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CONGRESS OF THE INTERNATIONAL ASTRONAUTICAL FEDERATION BUDAPEST HUNGARY 10-15 OCTOBER 1983 m m XXXIV CONGRESS OF THE INTERNATIONAL ASTRONAUTICAL FEDERATION

ABSTRACTS OF PAPERS

BUDAPEST, HUMGABr Oct. 10-15, FOREWORD

Abstracts included in this book art ordered according to the IAF nuuber assigned to each paper eooepted for presentation at XZZI? IAP Congress. Experience hae shown that the chosen arrangement is the nost conrenient one and allows the easiest access to the abstraots. The IA? paper nuBber can be found in the Final Programe of the Congress under: - the Technical Session,wbere the paper is presented - the author's name, listed at the end of the Programe. The Abstracts of the Student Conference and of Space Law Colloquium are at the end of this book. Abstracts of papers arriTed later than August 1st are not included in thie collection.

ftingarian Astronautieal Society - 2 -

IAr-83~O1 EXOSAT/DELTA - DEMONSTRATED SHORT-TERM BACKUP LAUIfCHER CAPABILITY THROUGH INTERNATIONAL COOPERATION by J. K. Oanoung, Manager, Spacecraft Integration, Delta Program McDonnell Douglas Astronautics Company G. Altnann, EXOSAT Project Manager, P. Eaton, Chief, Expendable Programs National Aeronautics and Space Administration J. D. Kraft, Delta Mission Analysis and Integration Manager, National Aeronautics and Space Administration ABSTRACT An important exploration of eosnie x-ray sources currently under wey Wan made possible by a unique example of international cooperation. The EXOSAT spacecraft, designed, developed, qualified, and prepared for launch by the European Space Agency (ESA), was successfully launched by the National Aeronautics and Space Administration (NASA) Delta launch vehicle in May 1983* EXOSAT was originally scheduled for launch on the European Ariane rocket, but due to unforeseen schedule realignments, ESA, in cooperation with NASA, selected the Delta for this mission in February 1983. The unique feature of this endeavor was the extremely short "lead time1* required to integrate the spacecraft and launch vehicle. This integration task, normally requiring 18 months of prelaunch preparation, had to be completed in only 3 months. Within this compressed schedule, the EXOSAT and Delta Projects had to complete not only the standard launch preparation activity (trajectory designs hardware drawings and analyses, operations planning, network support analyses, and hardware procurement and assembly), but a number of miasion-peculiar drawings and analyses (yo-yo despin and separation system designs, special experiment cleanliness requirements, special range safety analyses, and TM data link configuration requirements). Essential to the successful accomplishment of this seemingly Impossible task was the spirit of "International cooperation In space" - the theme of this year's IAP Congress. This paper desoribes (1) brief histories of the EXOSAT and Delta Programs, (2) the circumstances leading to this unusual integration activity, (3) the management and technical approaches for solving the sohedule compression problem, (1) the launch vehicle •edifications accomplished to satisfy the apaoeoraft requirements, and (5) a sunaary of those elements of the EXOSAT/Delta learning experience which could contribute to the achievement of continuing short-term backup launch capability. Several important conclusions are underscored by the EXOS&T/Delte experience. In forthcoming periods of high Icunoh rates and •ultiple payloads, there is a need for flexible scheduling in order to avoid oostly launch delays. This required flexibility can be aohieved by the short-tern osllup capability demonstrated by the EXOSAT/Delta mission, provided that a backup program is established and the neoessary management planning is implemented. _ 4. mm

IAF-83-02 THE NEED FOR ADDITIONAL SPACE SHUTTLE 0R8ITERS J. Jeffrey Irons Minority Technical Consultant Committee on Science and Technology Rayburn House Office Building - 2321 Washington, D.C. 20515 USA

Throughout recent fiscal year National Aeronautics and Space Administra- tion (NASA) authorization hearings, a number of witnesses have testified that the planned four Space Shuttle orblter fleet wilt be unable to adequately serve the projected space traffic requirements by the late 1980s. On June 15. 1982, the Subcommittee on Space Science and Applications held a hearing to examine the Issues associated with the need for Increasing the size of the orblter fleet. The Subcommittee on Space Science and Applications, one of seven subcom- mittees of the Committee on Science and Technology, has annual authorization of appropriations for NASA. A major portion of the civilian space agency's budget ts spent annually on developing the reusable Space Transportation System. As the system begins Its transition from developmental to operation- al status, a number of issues have emerged that require review by the Subcom- mittee. One of the most important and overriding issues is the need for additional orblters for the Space Transportation fleet. This paper deals spe- cifically with that Issue. A second, related objective of the hearing was to examine a concept which has been proposed by the Space Transportation Company, Inc. (SpaceTran) where- by the procurement of the fifth orbiter vehicle would be financed through In- vestments from the private sector. SpaceTran was formed in 1979 with the ex- press purpose of determining whether the private ownership and operation of a fifth Space Shuttle orbiter would be economically feasible. SpaceTran has re- ceived partial financial backing and support from the Prudential Insurance Company of America. In February 1982, SpaceTran submitted a proposal to NASA to procure an orbiter in exchange for exclusive marketing rights of foreign and commercial payloads aboard this vehicle. SpaceTran subsequently sent NASA a revised proposal In Hay 1982. To date, NASA has not evaluated the SpaceTran proposal. The Subcommittee attempted to examine fully the issues associated with the need for additional Space Shuttle orblters. Witnesses from within NASA, the American Institute of Aeronautics and Astronautics, Boeing Aerospace Company, SpaceTran, and Prudential Insurance testified on the requirements for a fifth or additional orblters; the feasibility and timing of the SpaceTran proposal; military and civilian launch requirements through the late 1980s; and the ability of the reusable Space Transportation System to adequately support both civil and national security missions. This paper addresses the previously mentioned Issues In detail, and sup- ports the discussions with excerpts of testimony and witness answers to written Subcommittee questions. - 6 -

IAF 83 04 DEVELOPMENT OF THE THRUST AUGMENTED VIKING ENGINE AND F1RSI STAGE DRAKKAR PROPULSION SYSTEMS FOR THE ARIANE 3 LAUNCHER. A. SOUCHIER, J. PASQUIER SEP Space and !iquid Propulsion Division On the Ariane 3 version of the Ariane launcher, 1st and 2nd stage perfor mances have been increased by use of a thtust augmented Viking engine. Other modifications for Ariane 3 include the use of two solid propellanl boosters 700 kN thrust each, burning for 28 seconds after lift off, and improvments 1n the third stage. All these modifications boost from 1750 to 2 585 kg the launcher capacity In geostationnary transfert .The program was decided at the beginning of 1980. First flight 1s scheduled for March 1984. SEP 1s the prime contractor for the studies and tests of the Ariane 3 first and second stages propulsion sy&tems (1e all the hydraulic and pneumatic systems Including the Viking engine).

The Viking thrust augmentation have beengobta1ned by chamber pressure augmentation from 54,5 10 Pa to 58,5 10 Pa. The pressure augmentation Increases the combustion Instabilities risks. Thus after the 10? launch failure following combustion instabilities in the Viking chamber It ap- peared that the thrust augmentation would be more difficult than planned. The Injector modifications developed after L02 flight were introduced on the Ariane 3 Viking but 1t was also necessary to change the fuel from pure UDMH to a mixture of UDMH an 25 % of hydrazine hydrate. First test with this new fuel occured in April 1901. With these two modifications Viking engines were able to operate satisfactorily at 65 10' Pa chamber pressure. During the ARiane 1 post L02 test program the strong effect of chamber configuration on combustion stability was discovered so it was decided to increase the stability margins by a chamber mortification on Ariane 3 : a circular gap at the upper junction between the composite throat and the chamber has been introduced to shift the chamber mecani- cal frequencies. This modification divides by a factor of three the cri tical combustion vibration level. A first chamber with such a modifica- tion was tested with succes 1n November 1981, since then other tests were conducted with success and decision to apply this chamber modifica- tion for Ariane 3 was taken in May 1982. Following all these stability improvmersts the first injector acceptance tests in December 1982 and January 1983 for ARiane 3 first flight ended with a 100 X success. For the first stage Drakkar propulsion system development, multiple lesis have been planned on the same propulsion bay with four engines on the PF 20 test stand at SEP Vernon. The propellents are fed to the bay in a configuration quite similar to the first stage flight tanks configura- tion. Thanks capacity reaches 220 tons as for the Ariane 4 launcher. Thus the tests may last for 210 s compared to the 135 s in actual Ariane 3 flight. First test the 9th of November 19B2 was stopped after 154 s followlnf a safety measurement failure not related to funct>onnai problems. However this test showed a thermochemical reaction between -7 -

the pressurization hot gases and propellent vapors in the UDMH tank. This problem was solved by decreasing the pressurization gases temperature 1n that tank. Mathematical models, scaled down tests and the following bay demonstrated this solution. The first following bay test occured 1n Janu- ary 1983. The end of these tests Is planned for September 1983 and the engine quali- fication Is scheduled for Octobre 1983. Other modifications have been developed for Ariane 3 such as the engine gimbalUng actuators hydraulic connection to Increase re11ability or new unions to bear without leakage the more severe vibration levels crested by the solid boosters operation. - 8 -

fAF-83-06 THE COST EFFECTIVENESS OF A MODULAR ROCKET - William Nagy and Howard C. Tlnney, THE BOEING COMPANY

SUMMARY This paper shows the methodology and mathematical formulations developed to compare, on an evaluation criteria basis of $/lb. of delivered pay- load, a modular booster compared to a single-purpose booster on a "cradle-to-grave system basis". It also shows that by the use of parameterization of the payload size, numbers and space locations, tlie use of subject uncertainty can be avoided. The paper also shows that a substantial number of, but not necessarily all, boosters have, in fact, on a worldwide basis, developed on a modular basis, but that the full power of the modular concept has not been exploited. BACKGROUND In the early 60's, Ihe USAF authorized a amiLlmillion Uollat, cJasslfirA, In-depth study of the future liquid-propelled rocket booster require- ments for space shots. One of the peculiar parameters of the stu:ly wan unidentified sizes, numbers and location of these payloads. The Boeing Company undertook the study at a time when cost-effectiveness and the cradle-to-grave systems analysis approach were still buzz word« over the horizon. While I cannot 9ay that we were alone as the first t< apply these analytical approaches, I can say emphatically that we independently Invented this approach and used it for the first time ;JS the basis of the study. METHODOLOGY Two basic system concepts were used: a unique booster for each space shot and a nodular concept. The comparison evaluation criterion was common: dollars-per-pound of delivered payload. Since the quantities, sizes and locations of payloads waa purposely not fixed, we used these parameters as floating for both basic vehicles. We then compared the range of each of these parameters over which each of the two vehicles van best. We found that the modular booster was superior over a much wJdet range of these parameters than the single-purpose vehicle on a dollars/ lb. of delivered payloads basis. —i 9 _

IAF-83-06

PARAMETERIZATION This tool provided a marked advantage over the use cf probabilities. We compared the effects of staging, propellants, length of burn, materials of construction, development cost and reliability on the evaluation criterion in terms of both cost and payload. He found that the use of high-specific Impulse propellants was the way to go.

WORLD TRENDS It is now of interest to note whether the world-at-large has accepted these forecasted trends. In a "mixed-up" way, they have. Here are some examples: the space shuttle, the Delta; the Ariane, the new private-sector German firm. It is also interesting to note that, as far back as the time study, the Soviets had implemented thia approach in a more-or-less fashion on the Vostok vehicle. Others. While I am not privy to the details of the new eleven million pound booster the Soviets are alleged to be working on, the odds are quite high that it, too, will be modular in some form.

CONCLUSIONS The thesis of this paper is that:

1) the modular concept provides a long-range flexibility, which the single-purpose vehicle does not, In a cost-effective manner;

2) that while the modular concept has been largely implemented on a "non-pureform", it has not been exploited to its full advantage; and

3) that it would be most likely, excepting very unusual circum- stances, to be to the economic and time advantage of nations to recognize the inherent values of a purer form of the modular rocket booster. - 10 -

IAF-83-08 SPACE SHUTTLE SAFETY REPORT — THE FIRST SEVEN MISSIONS Nelson E. Brown and Jeri W. Brown Lyndon B. Johnson Space Center National Aeronautics and Space Administration Houston, Texas U. S. A. By mid-1983 seven Space Shuttle missions have been flown tiy th«> United States, with 21 astronauts and various international OJMIU elements launched into earth orbit. The first four Mights (M'.-l through 4) were classified as test flights by NASA and designed In collect performance data on the Space Transportation System (SIS). Hie latter three flights (STS-5, 6, and 7) transported hoth payloads that remained attached to the Shuttle Orbiter and international communications with upper stages that were deployed by the Orbiter for insertion into geosynchronous . Precluding unforeseen major problems, by mid-1984 some 10 to 12 additional launches will be completed with about 50 astronauts participating. In future years, the STS flight rate will reach or exceed 24 annually with astronaut/crpwnipnibpr participation in the 100-120 range. As in the development of any complex aerospace program, problems and anomalies have appeared in the Shuttle Program thus far. On a flight-by-flight basis, each problem area is recorded and its resolution tracked and documented through completion. Problems and anomalies with potential safety implications for astronauts, ground crews and populations, STS components, and payioads are resolved prior to the next flight. Non-safety critical problems are normally resolved prior to thp next flight but, depending on operational criticality, ran be delayed to later flights to avoid Impacting payload manifesting ami mission schedules. Problems have occurred across several STS subsystems at various criticality levels. For example, on STS-1 a somewhat minor problem in the Orbiter flight software timing sequence between primary and backup computer operation resulted in a two-day launch delay. The computers control Grbiter operations. On STS-2, an out-of-tolerance lubricating oil pressure measurement on Orbiter auxiliary power units (API!) numbers 1 and 3 caused by clogged filters resulted in delaying the launch eight days. The auxiliary power units provide hydraulic power to drive the orbiter aerosurfaces, main engine control valves and gimble actuators, the brakes, nose wheel steering and landing gear deployment. Ais<», the planned 5-day STS-2 mission was reduced to 2 days-6 hours

In the flight of STS-3, during Orbiter tail-to- attitude, the payload bay doors jammed before fully closing on the first attempt but closed on subsequent testing operations. The probable cause suggested a foreign object jamming the latching mechanism. Also, the wrist TV camera on the Remote Manipulator System (RMS) malfunctioned due to an electrical short inside the camera power supply, thereby compromising the acquisition of RMS dynamic test data. Landing of STS-3 was extended one day due to wet lakebed runway conditions at the primary landing site. On STS-4, as during several other flights, various anomalies and/or malfunctions were recorded in the APU and fuel cell systems, such as oil pressure,, leakage, temperature, and heater operation. The Solid Rocket Boosters on STS-4 were destroyed on water impact due to malfunctions in the parachute deployment system. STS-5 crewmembers encountered problems with the extravehicular mobility units (EMU-integrated spacesuit and life support system) causing cancellation of the first Shuttle space walk. Inflight attempts to repair the EMU's were unsuccessful. Cathode ray tube (CRT) number 2 went blank 30 minutes into the STS-5 flight. Inflight maintenance was successful in restoring the CRT operations. The STS-6 mission was postponed due to a hydrogen leak in the Orbiter's aft compartment. The leak developed from a crack in a cooling tube in one of the three main engine nozzles. During ascent, a CCTV monitor bracket at the aft flight deck station debonded from the bulkhead. During STS-7, one of the Orbiter windows was pitted by a meteoroid. Approximately 375 off-nominal conditions/problems have been recorded through the flight of STS-7. Many of the off-nominal conditions were one-time, non-generic component malfunctions warranting only adjustment or repair/replacement. Others presented conditions that required real-time action to avoid compromising crew and equipment safety. Excluding the loss of two solid rocket boosters, all problems were resolved while limiting hazardous conditions to personnel and equipment within the program design guidelines. This paper summarizes a review of all documented problems, anomalies, malfunctions, etc. for the first 7 STS flights. Those problems having direct safety implications are identified and categorized with respect to personnel (flight and ground crewmembers), vehicle, and payloads/experiments. These problems are discussed with respect to their immediate (e.g., inflight repair) and/or long-term (e.g., system redesign) solutions. Based on the initial flight experience (STS 1-7), trends that could cause hazardous conditions for future missions are identified. Special emphasis is placed on international cooperation among vehicle, payload, and experiment engineers, designers, planners, and crews to ensure future program safety for both Space Shuttle operations and planning and implementation. - 12 - IAF-B3-H

Chemical Orbit Transfer Vehicles - Options for the Future

M. G. Wolfe and J. E. Bennett The Aerospace Corporation El Segundo, California

The United States National Space Transportation System (STS) is presently com- posed of the Space Shuttle (SS), for transfer of payloads from ground to low earth orbit (LEO), and the Inertial Upper Stage (IUS) and the commercially developed Payload Assist Module (PAM-A and PAM-D) series for transfer of pay- loads to higher energy orbits. Also, planned for the 1986-7 time period are the -derivative (Centaur G and G') cryogenic upper stages. In addition, it is anticipated that a number of spacecraft will utilize Integrated Propulsion Systems (IPSs) for orbit transfer rather than utilizing the available generic stages. (In the IPS concept the propulsive stage depends on the spacecraft sub- systems for all or some of such functions as guidance and navigation, attitude control, and power; and the propulsive subsystem may be physically Integrated into the spacecraft. Frivateiy-runded commercial interests will likely develop the Transfer Orbit Stage (TOS), which falls within this class.)

The Shuttle/Inertial Upper Stage (IUS) provides the capability to launch single spacecraft weighing up to 5,000 lb to high energy orbits. The recent approval of the Shuttle Centaur program will lead to this capability being doubled in 1986-87. At the same time, it is anticipated that requirements will eventually exceed these capabilities. Also there will be a need for more operational - ibility in orbit, such as low-thrust deployment, maneuvering on orbit, recovery of transfer vehicles and payloads, manned transfer and return, basing of transfer stages in orbit, and so on. It is necessary to investigate how the existing TUS and planned Shuttle/Centaur transfer vehicles can be used as departure points for vehicle developments that could satisfy these orbital transfer and operational needs.

It appears that the two generic etages, the IUS and the Centaur, by necessity, will provide the technology base for improvements in orbit transfer payload capebility and operational flexibility through the late 1980s and 1990s, and a number of potential scenarios can be developed using this guideline. It is appropriate to configure these scenarios in relation to potential near-tern, mid-tern and far-term requirements. For simplicity in this paper vehicle per- formances are normalized to geosynchronous equatorial orbit (GEO) payload capability.

Using the. IUS and the Shuttle/Centaur as a base, a set of near-tern, mid-term and far-term scenarios are constructed which provide graceful development paths to greater performance and operational flexibility. Supporting technologies that will be needed are also identified. Requirements to deploy, to high energy orbits, payloads of over 40,000 lb and recover payloads of over 20,000 lb are considered, and specific vehicle configurations identified. It is concluded that the IUS end Shuttle/Centaur technological base provides a firm foundation for the development of advanced chemical orbit transfer capability and the new technologies that vill likely be needed In addition can already by identified for the foreseeable future. - 13 -

IAF - 83-13

A Modular Orbit Transfer and Logistics Vehicle (IQTLV) for Future Orbital Operation

Dietrich E. KOELLE, Wolfgang KLEINAU, MBB/ERNO Space Division Ottobrunn/FRG

This paper presents the results of a recent study for the German space program* whereby the mission requirements and the basic modular approach have been established in two study contributions for ESA**. The future space operations scenario with permanent platforms requires a vehicle for orbital maintenance and logistics. This Is a new require- ment in addition to the present demand of propulsion vehicles/stages for high-velocity missions and planetary orbit injection (I.e. Galileo Retro Propulsion Module). As an economic solution, in order to avoid development of different types of vehicles, a modular approach is being presented, designated the "Inter- orbital Transfer and Logistics Vehicle" (IOTLV). The modular concept comprises 6 different modules which can be combined to different mission-dedicated vehicles. IOTLV MODULAR BUILDING 12 3 4 5 6 BLOCK SYSTEM

1 = Modular Orbital Propulsion System MOPS

2 = Modular Auxiliary Tank System MATS

3 = Modular Orbital Servicing System* MOSS

4 = Modular Equipment and Avionics System* MEAS

5 = Modular Orbital Re-entry System* MORS

6 = Modular Orbital Crew Cabin MOCC

* wfth or wMtwrt DSM lOeckinf Sit-MoMt) The basic unit is MOPS, the modular orbital propulsion system, used on all vehicle types. The propellant mass and performance can be doubled by an auxiliary tank module (MATS, and it can be made an autonomous ve- hicle by adding the equipment and astrionics system (MEAS). Manned ser- vicing operations are feasible by adding a crew cabin (MOCC) and the orbital servicing system (MOSS). Moreover a submodule for rendez-vous and docking (RVD-DMS) has been de- fined, which could be attached either to MEAS, MOSS or MORS depending on the mission requirements. With the above 6 elements more than 6 different IOTLV-types could be bui 11. up which would cover at least the 16 missions, defined in our studies. The main application of IOTLV Is devoted to (1) servicing and maintenance of a space station or of freeflying plat- forms in the low Earth orbit, as well as the implementation of logistics and refuelling of permanent space stations in a sun- synchronous orbit MOPS + (MATS optional) + MEAS + MOSS (plus the RVD-DMS attached to MOSS) (2) orbit reconstitution of a space station or boosting or reboosting of spacecraft, or collection of debris MOPS + (MATS optional) + MEAS (plus the RVD-DMS attached to MEAS) (3) retrieval of material processed In space or the application of rescue maneuvers MOPS + MEAS + MORS (plus the RVO-DMS attached to MEAS or MORS) (4) transfer of crews between the launch vehicle and the space station for crew rotation or to freeflying platforms for inspections MOPS + MEAS + MOCC (MSS optional, RVD-DMS-partly) (5) inter-orbit-transfer of spacecraft, acting as a autonomous stage, by example between LEO and GEO MOPS + (MATS-optional) + MEAS (6) boost augmentation, or perigee-respectively apogee Injection module MOPS + (MATS-opt1onal). The IOTLV-concept 1s conceived for the Interface considerations of the ARIANE-4 family and will be made compatible for the launch and retrieval through Shuttle by a cradle, a Spacelab Pallet-derivative. As a versatile teleoperating, commuting and logistics vehicle, the IOTLV would cover both, future needs for a European Infrastructure and a contribution to an international operation center. The basic MOPS employs an unified b1-propel1ant propulsion system for transfer and reaction control with a 2/3 kN transfer system and a number of 10 N-thrusters, exploitating current European technology under de- velopment or being Implemented In the Galileo retro-propulsion module. The module development can be performed by the European countries and/or in a coordinated effort with NASA.

-Study on Inter-Orbit Transfer and Logistics Vehicle, BMFT-DFVLR-BPT, 1983, 01 QV 432-AK/SN ** -Definition Study on European Spare In Orbit Infrastructure ESA A0/1-1.451/82F -Manned Space Station Support Study ESA AO/1-1.473/62 - 16 -

IAF-83-15 The Use of Long Tethera for Payload Orbital Transfer

by

M. Martinez-Sanchez Massachusetts Institute of Technology Department of Aeronautics and Astronautics

1. Introduction

Although rocket propulsion will continue for the foreseeable future

to be the primary method for moving payloads in space, we vill probably

witness a gradual progress towards exploiting for that purpose some of

space's unique environmental conditions. Planetary gravity assist, in

use today, represents one of the first such applications. Geomagnetic-

propulsion has been proposed, and looks particularly promising when im-

plemented by long tethers (Ref. 1). Solar sailing also remains a tanta-

lizing possibility.

In this paper we explore a variety of concepts for orbital transfer

which all exploit the substantial gravity gradients which can be produced

with very long, ultralight tethers. The recent initiation of the joint US-

Italian Tethered Sub- program is sure to stimulate research on a

broad range of similar applications, as well as provide fundamental data

and verification tests on some of them.

It is well known that in an extended orbiting body, only a certain

point (the orbital center) Is in true gravitational-centrifugal equilibrium,

ail others being unbalanced to various degrees. This aeans that internal

forces must develop to keep the body together. For elongated bodies, the

imbalances are such that the body tends to align itself with the local - 17 -

vertical, and a tension develops along the axis. For the limiting

case of a dumbbell in circular orbit, with masses mi and m? connected

by a mass-less tether of length L, this tension force, F, is

minis 2 F= 3« Lm12 i m,2 - — ~ (1)

where il2 is the angular velocity of orbital motion. If the tether is

now cut, the upper body is free to gain altitude, and it enters an

elliptical orbit whose perigee is at the release point (see Fig. 1);

simultaneously, the lower body enters a lower elliptic orbit, «;irh

apogee at the release point. At the point of maximum separation, 180°

after release, the distance between the two bodies is, to first order

in L/R (R - orbital radius), equal to 7L, and the center of mass,

again to first order, remains in its original circular orbit. Thus, if

one body is more massive, its altitude disturbance is proportionally

smaller, and we tend to refer to it as "the platform," while the lighter body is variously called "the satellite" or "payload."

From the description of the above idealized experiment, It can be seen that the tether acts as a momentum-exchange device which imparts an Impulse to one mass using the other one as the reaction mass. This opens up a number of possibilities that we wish to explore in what follows, but first it is desirable to define more precisely our concept of the tether as a momentum-exchange device.

Momentum exchange implies conservation of total aomentua along the orbital path, and therefore conservation of "AV" in the usual propulsive sense. - 18 -

Consider two alternative ways of raising the orbit of a mass m by a certain (small) amount: (a) to deploy m from another mass M by means of a tether of appropriate length L, and then release m into a higher elliptic orbit, and (b) to use a two-impulse propulsive transfer between the same orbits. It is understood that in case (a) the lower mass M is restored to its initial orbit by means of similar propulsive impulses. The statement, which is proven to first order in Appendix 1, is chat both methods use exactly the same net impulse,

AI •2 u L m (2) and therefore, would use the same amount of propellant if rockets of equal specific Impulse are used in the satellite and the platform.

This conservation property serves to set a limit to the kinds of orbital change schemes which are possible; the exception is that, as will be also discussed, long-term accumulation of very small second order effects can also be put to constructive use by means of tethers. Within these boundaries there is still a very wide range of possible applications and variations of these. For instance, the purely static release discussed so far ("hanging" release) can be replaced by release from a tether librating in-plane, the libration being controllable by tension control at the platform ("swinging release")* This node of operation increases or decreases the amount of momentum transferred, depending on the phase of the oecillat.on at release. It adds an element of timing requirement to the mission, but it affords additional flexibility in the choice of tether length. In fact, the concept can be extended to full rotation of the satellite-tether-platfors system ("spinning delivery")* with further additions to both complexity and flexibility. IAF - 83 - 16 Comparison of Advanced Propulsion Systems in Cis-Lunar Space Ulrich Thomas Technische Universitat Berlin Institut fur Luft- u. Raumfahrt 1000 Berlin 10, FRG Abstract This paper presents the results of a comprehensive analysis of near to medium term propulsion systems for cis-lunar space application. Space transportation systems taken into consideration are equipped with chemical engines fueled by and aluminium powder, oxygen ion engines, solid core nuclear engines and nuclear light bulb engines. Studies indicate that oxygen and aluminium-powder can be produced from lunar material. Liquid hydrogen for the nuclear engi- nes will be supplied from earth. The market envisaged are support of nuclear waste disposal on the lu- nar surface and/or construction of SPS in geostationary earth orbit. If these materialize they require mass flows from earth to lunar sur- face as well as from lunar surface to geosynchronous earth orbit. II is shown that the most fuel efficient permanent space transportation system is not necessarily the most economical choice. Preliminary re- sults indicate that for lunar surface to lunar orbit transportation liquid oxygen - aluminium-powder engines will be most cost effective with average specific transportation cost of 20 $ (1980}/kg. Liquid oxygen-/liquid hydrogen-engines are very competitive for lunar orbit - geosynchronous orbit roundtrips. Solid core nuclear engines can be employed for low earth orbit to lunar orbit transportation with spe- cific transportation cost of approximately 50 $ {1980)/kg. Nuclear light bulb engines raise these transportation cost to 100 $/kg be- cause of expensive engines used. The electrical ferry is the most fuel efficient transportation system, but high investment and hardware cost, spare part requirements and maintenance increase cost considerably. For these reasons the elec- trical propelled ferry is the most expensive vehicle for lunar orbit to geosynchronous orbit transportation, specific transportation cost for this alternative will be as high as 170 $ (1980}/kg. Thus it can be shown that no major breakthroughs in rocket engine technology are required for an economical lunar Industrialization. key words Advanced Propulsion Systems/Life Cycle Cost Analysis/Space Transpor- tation System Comparison/Specific Transportation Cost/Lunar Indu- strialization. - 20 -

IAF-B3-1B Shuttle/Centaur - More Capability for the 1980's Omer F. Spurlock NASA/Lewis Research Center, Cleveland, OH

In July of 1982 the decision was made by NASA to modify the Centaur uppet stage for use with the Space Shuttle. This high energy upper staqe, UBUKJ hydrogen and oxygen propellents, is a^new configuration of the stage currently used with the Atlas and previously with the Titan boosters. Atop the Atlas, Centaur has placed many commercial communications satellites in geostatlonarv orbit, launched several scientific satellites into low earth orbit, and boosted a series cf Mariner and Pioneer spacecraft to Mercury, Venus, Mars, and Jupiter/. As an upper stage on the Titan, Centaur launched the Helios, Viking, and Voyager spacecraft to the sun, Mars and Jupiter/Sat urn respectively. As a Shuttle upper stage. Centaur will continue to play a maim role in the exploration of the system. In 19B6, It will launch the International Solar Polar Mission spacecraft around Jupiter where it. will use Jupiter's gravitational field Lo fall back over the solar poles to exploit th«> out-of-the-ecliptic region of the solar system for the first time. It will also launch the Galileo spacecraft in the same year to orbit and probe Jupi- ter. The capability developed tc launch these ambitious missions will be available for future generations of large satellites devoted to serving the needs of man.

The Shuttle/Centaur and attached spacecraft will he carried in the cargo bay of the Space Shuttle into a low earth orbit. After a few revolutions of the earth, the Centaur and spacecraft will be deployed by the Shuttle and shortly thereafter the Centaur will ignite its engines and inject the spacecraft Into the desired final orbit.

The Shuttle/Centaur is designed to make maximum use of the existing Centaur design and therefore uses proven Centaur hardware wherever feasible. The major changes include increasing available propellents by lengthening the oxygen tank and lengthening and increasing the diameter of the hydrogen tank. Most other changes are safety related. It is designed to optimize the total vehicle system performance characteristics consistent with minimizing the impact on the Shuttle and meeting the safety requirements characteristic of a manned vehicle.

The Shuttle/Centaur has a 3.05 meters (120 in.) liquid oxygen tank and 4.32 meters (170 in.) liquid hydrogen tank holding a total of about 20,865 kg (46,000 lbs.) of propellents. The tank walls utilize the thin-ekin and pres- sure stabilization technology developed for the Atlas and Centaur tank de- signs. The tanks are insulated with foam blankets to Minimize the boil-off of cryogenic propellents. A vacuum bulkhead separatee the two tank* to reduce heat transfer between the oxygen and hydrogen tanks.

The main propulsion system is similar to that of the Atlas/Centaur and con- sists of two Pratt and Whitney Aircraft RL-10A-3-3A engines rated at 73,392 newtons (16,500 lbs.) nominal thrust, each operating at a 5/1 mlxtute ratio of oxidizer to fuel. The specific impulse of the engines in 446.4 seconds with the incorporation of a silver throat. - 21 -

In-tank propellant sensing probes indicate propellent levels during flight. With this information, engine mixture ratio is adjusted throughout flight such that at propellant depletion residuals are minimized for maximum vehicle performance.

The reaction control system for the Shuttle/Centaur used for attitude control during coast phase consists of twelve 27 newtons (6-lb.) hydrazine thrusters. The thrusters are fed from a positive expulsion bottle capable of holding 77 kg (170 lbs.) of fuel. Additional bottles can be added if future missions require more control capability.

The Shuttle/Centaur uses an autonomous inertial guidance and control system independent of the Shuttle to provide near optima] trajectories to desired injection conditions. This flexible system is very accurate and has proven high reliability over the 67 flights of the Atlas/Centaur and Titan/Centaur vehicles. An onboard digital computer manages the vehicle systems and programs all required vents and maneuvers after separation from the Shuttle.

The interface between the Shuttle and Centaur is the Centaur Integrated Sup- port Structure (CISS). The CISS, which is installed in the Shuttle cargo bay, provides the mechanical, electrical, and fluid interfaces between the Shuttle and Centaur systems. The CISS includes the support structure and erection mechanism for the Centaur. The propellant fill and drain lines pass ftom the umbilicals through the CISS to the Centaur. The electrical interface between the Shuttle and the Centaur is also routed through the CISS.

Because the Shuttle is manned, numerous redundant electronic and fluid system/components are required. To save Centaur stage weight, the CISS in- cludes as many of these items related to Shuttle safety as possible. Redun- dant computers, valves, and other components are thus mounted on the CISS rather than attached to the Centaur. The Centaur is supported from lift-off to deployment in a quiescent state, with the CISS monitoring Centaur systems to insure Shuttle safety. This serves to increase the mass fraction of the Centaur, improving mission performance capability. Since the CISS is returned with the Shuttle, its components are reusable, cutting costs.

The performance capability of the Shuttle/Centaur for planetary missions is greater than any other United States launch vehicle to date except the and exceeds the Saturn V for deep-space missions. For the Galileo mission the Shuttle/Centaur will send a 2550 leg (5632 lb.) spacecraft to Jupiter in 1986 at a C3 of 80 km2/sec2. The International Solar Polar Mission spacecraft weighing 372 kg (820 lb.) will set a new speed record for man-made objects, leaping toward Jupiter at a C3 of 133 km2/see2. The capability of the Shuttle/Centaur in about 5897 kg (13,000 lb.). The cargo bay length available for spacecraft with the Shuttle/ Centaur is about 9.1 meters (30 ft.), half the length of the bay. A shorter version of the Shuttle/Centaur will also be available, increasing cargo length capability for long payloads to 12.2 meters (40 ft.) but reducing payload capability to 4536 kg (10,000 lb.).

In summary, the addition of the Centaur to the fleet of Shuttle upper stages offers attractive possibilities for large earth satellites and ambitious interplanetary exploration. This reliable high performance stage will be available in 1986 to serve the needs and aspirations of both the commercial and scientific communities. - 22 -

IAF-83-21 COMMERCIAL ATLAS/CENTAUR PROGRAM D. E. CHARHUT J. E. NIESLEY GENERAL DYNAMICS CONVAIR DIVISION

General Dynamics Convair Division has been successfully launching the Atlas/Centaur launch vehicle for the past two decades. Half of the launches have boosted communication satellites into orbit and the success record established over the last twelve years is 95 percent. Firm Atlas/Centaur launches now extend into 1*387. even though NASA had scheduled to phase out the vehicle by 1981 with the advent of Shuttle. During the last few years, it became increasingly clear that Shuttle capability to carry all space traffic was optimistic. Ariane's entry into the marketplace certainly proved that an expendable launch vehicle could attract customers if the launch costs were competitive. With the new Federal Administration's philosophy of less government and more free enterprise, it appeared the time was ripe to evaluate a commercial launch vehicle venture using the flight-proven Atlas/Centaur design. The initial step in making such an evaluation was to determine size and stability of the market. Commercial and foreign communication satellites were selected as the target market since their projected growth was rapid, the market was reasonably stable, and they require launching on schedule. Approximately 200 of these type spacecraft were forecast for the 1906-95 time period, with about a third of these in the Atlas/Centaur class of payload capability. Atlas G/Centaur delivers 5,200 lb. (2,360 Kg) Into synchronous transfer orbit which 1s more than adequate to launch direct broadcast satellites planned for the mid 1980s. However, this capability exceeds require- ments for the PAM-D and PAM-DII class spacecraft and is Inadequate for an INTELSAT VI launch. Therefore, General Dynamics has designed a family of launch vehicles called Atlas Il/Centaur which will have the capability of launching dual PAM-DII spacecraft, or a large, direct broadcast satellite and a PAM-DII satellite. The larger of these vehicles delivers 11,200 lb. (5,100 Kg) Into geosynchronous transfer orbit. This family of Atlas II/Centaur vehicles, combined with the Atlas G/Centaur, has the capability of addressing most of the communi- cations satellite market over the next decade. As a means of Implementing the commercial Atlas/Centaur program, General Dynamics has formed a separate commercial entity called "CommSpace" on March 1, 1983. The paper discusses current status of the Atlas/Centaur program, In- cluding launch history, vehicle success record, and current flight schedule. Events leading to the decision for commercialization are covered, Including: assessment of launch demand versus Shuttle capa- bilities, commercial market growth, Ariane market entry, and the current administration's policy which supports commercial space enterprises. A brief summary of the market analysis 1s presented showing probable Shuttle overflow and an assessment of the communications satellite market. The proposed commercial Atlas/Centaur family is presented, Including the current vehicle called Atlas G/Centaur and growth vehicles named Atlas 11/ Centaur. Vehicle elements required to satisfy the various mission require- ments are outlined, as well as design features of the family and its per- formance capability. The paper also discusses availability of the various Atlas/Centaur versions and the commercial organization called "ConwSpace" which will Implement commercialization of the Atlas/Centaur program. 1AF-82-23 PROCESSING CARGOES TOR THE FIRST TWO OPERATIONAL STS FLIGHTS AT KSC John J. Neilon NASA, Kennedy Space Center, FL ABSTRACT The principal "customer" of the Space Transportation System is the deployable or free flying payload. In the early years of the program at least this class of payload is dominated by "the conmercial geostationary connunication satellite. The capability of the STS, as opposed to a typical expendable launch vehicle, allows several of these payloads to be assigned to the same flight. To the payload processing cctmunity at KSC, the challenge was to find or create facilities for customer preparation of such payloads in a timely fashion, to devise methods to verify the orbiter/ cargo interface before the actual insertion into the orbiter, and to integrate the various payloads into a single cargo. NASA's typical approach to such a situation is to survey facilities used in previous programs and attempt to adapt them to the new problem at hand. In this case, the unmanned or expendable programs have for years had a requirement similar to that of the STS, to provide suitable areas for a customer to check out his spacecraft, mate it to an upper stage, if required, prior to mating with the launch vehicle. For an individual payload of the size compatible with the Delta, this process can be carried out in similar or the very same buildings used today. In the case uf such payloads, since they must be launched with others in the cause of economy, integration of the several payloads into a cargo requires an integration facility capable of acccmrodating hazardous materials. In the case of larger payloads requiring apogee and perigee motors larger than Delta class, the actual mating of upper stage of spacecraft also takes place in the integration facility. Fortunately, a building used for preparation of Titan Centaur class payloads was available at KSC and was capable of modification to meet the STS cargo requirements. These modi- fications accommodated not only the mechanical work stands required for physical mating and assembling the cargo elements but also the particular ground support equipment and simulators required to verify the cargo to orbiter interface before actually mating with the orbiter. Concurrently with the facility modification and the development of the GSE and simulators, processing plans and procedures were formulated to meet expected workload.

Vfe can now look back to the actual processing of the cargoes for the first two operational flights of the STS (after a four-flight orbital flight test). The cargoes for these two flights were, appropriately enough, geostationary comnunication satellites and their accompanying - 25 -

apogee and perigee stages. .For STS-5, the principal payloads were the ANEC C-3 and the SBS-3 satellites, both manufactured by Hughes Aircraft Company and both boosted into geosynchronous transfer orbit by the McDonnell Douglas Astronautics Company PAM-D solid motor and into synchronous orbit by Thiokol STAR-30 apogee motors. The principal payload for STS-6 was the Tracking and Data Relay Satellite (TDRS) intended for government use in support of the STS. The Space Comn/TRW spacecraft is boosted into geosynchronous transfer and thence to synchronous orbit by the two-stage Boeing Inertial Upper Stage (IUS). The assignment of the two spacecraft of STS-5 emphasizes the cooperative and international features of the Space Transportation System—one satellite owned by a commercial American organization and the other by a quasi-governmental organization of another country, in this case Canada. The facilities utilized for these missions and the modifications necessary to adapt them to STS use are described as are the processing plans. The successful checkout and launch of these missions indicates the soundness of our approach. Much work remains to be done in applying the lessons learned in these flows to the task of simplifying and improving procedures toward the objective of a more economical and efficient operation. - 26 - IAF-83-25

IRIS - A NEW ITALIAN UPPER STAGE SYSTEM

Prof.Ing. E.VALLERANI Ing. F.VARESIO Ing. L.BUSSOLINO Director of AERITALIA AERITALIA Space Sector AERITALIA Space Sector Space Sector IRIS Program Manager IRIS System Engineer

AERITALIA Societa Aerospaziale Italians 41 Corao Marche, 10146 TORINO (ITALY)

One of the moat interesting possibility offered by Space Shuttle, exten ding ita capability, ia to support the flight of upper stage systems that can place satellites or payloada in geostationary transfer orbit or high energy orbit. This attractive capability has stimulated the development of a family of upper stage systems capable to fulfil the requirements of a large variety of spacecraft and payloada. One component of thia family is represented by IRIS System (Italian Re search Interim Staga), an upper stage of the Space Shuttle completely conceived and developed in Italy by National Aerospace Industries lea- ded by Aeritalia. The IRIS program is sponsored by the Italian Government through the "Piano Spaziale Nasionale (P.S.N.)" of the "Consiglio Nationale delle Ricerche (C.N.R.)". The objective of IRIS System ia to provide a commercially interesting and reliable launcher system for injecting a nominal payload of 900 Kg mass in geostationary transfer orbit. Payload of 600 Kg mass can be al^ so launched using a solid rocket motor off-loaded down to 75Z as well as payloads in the range from 450 Kg up to 600 Kg can be orbited with a combination of solid rocket motor off loading and different orbit transfer strategy. The IRIS System consists of: - an Airborne Support Equipment (A.S.E.) that is attached to the Shut- tle orbiter cargo bay and is a reusable module with all subsystems necessary to fulfil the mission requirements. - IRIS Spinning Stage (I.S.S.) module that is spin stabilized, deplojra ble and expendable stage carrying the payload to be launched. - 27 -

The A.S.E. module supports the composite (I.S.S and the payload) in car_ go bay during launch and ascent and deploy it once in orbit via a sepa- ration subsystem. Various A.S.E. subsystems allow to perform the IRIS mission: - the spin table spins up the composite for stabilization. - The sunshields protect the payload from the environment influence with fixed and movable "clam shell" parts that allow the I.S.S. and payload deployment utilizing a proper separation device. - The data handling, incorporating a redundant microprocessor, can con- trol, monitor and command the A.S.E. mechanisms. It actuates arm and disarm functions of ISS and payload providing al- so control and monitoring of all functions of payload up to the deploy^ ment. The ISS provides payload with the needed power for the coasting phase lasting 45 minutes, during which the composite is going away from the Shuttle. Once the correct position on orbit is achieved, the solid rocket motor gives the necessary impulse for the injection of the payload in the ge£ synchronous transfer orbit. The ISS module is consisting of an advanced technology and a payload attach fitting, on top of the motor, supports the payload interface (ARIANE SYLDA Type) and a circular platform, on which are the ISS main subsystems: - the nutation control subsystem that has to control the attitude of the composite, once deployed, reducing the nutation; - the electrical sequencing subsystem that performs the preprogrammed mission sequence, commanding all the operations of the composite up to the final payload separation; - the telemetry subsystem collects the performance data and transmits them to the Orbiter to verify the correct operation of IRIS. The IRIS program is now nearing to the completion of phase B and is going to the development and qualification phase necessary for flight. This paper describee the background, the configuration and the perfor- mance of IRIS System. IRIS payload requirements are also indicated: the IRIS program develop- ment plan as well as the progress status are briefly discussed. - 28 -

IAF-83-29 THE SPACE STATION AN OVERVIEW OF THE DESIGN PROCESS Clarke Covington Manager, Space Station Project Office Johnson Space Center Houston, TX 77058

ABSTRACT

The primary purpose of a permanent space station is to physically accommodate a desired set of missions and to provide the space-based utilities and services necessary to support these missions and itself over an extended period of time. The space station can be thought of in two functional parts. One is the "core" part of the station which includes the volume, habitability, operational equipment, and all the accouterments necessary to optimize the productivity of the space sta- tion crew members for the management and service functions that they provide in support of the missions. The other part of the station in- cludes the mission-specific facilities which are attached to and oper- ate with the core to accomplish individual or classes of missions. To be responsive to user needs, the space station design process begins with mission requirements which are time-phased by need or de- sire for inclusion into a "mission model." From this model, an overall system architecture is defined which includes the basic manned space station, other space elements which operate with or are operated from the manned space station, and mission-specific facilities and modules which are attached to the core and become a part of the space station. Design requirements for each of the system elements are then developed from the system architecture requirements. Mission requirements that drive design requirements include low- earth-orbit free-flying satellites and platforms requiring periodic servicing or unscheduled repair; launch and recovery of reusable upper stages for transporting commercial satellites to geosynchronous orbit or unmanned scientific spacecraft to interplanetary trajectories; assembly operations for constructing satellites too large for deploy- ment from a single shuttle payload bay; and dedicated attached modules or pallets for science, applications, and space processing development. From specific requirements for these missions, mission-specific facil- ities can be defined to support them. A flight support facility is re- quired with the equipment to launch, recover, and service Orbit Trans- fer Vehicle (OTV) and Teleoperator Maneuvering System {TMS) space sys- - 29 -

terns. This facility has to include subsystems for tracking, remote control, and berthing as well as equipment and operational techniques necessary for module replacement and propellent transfer. Satellite servicing facilities can use some of the same equipment required in a flight support facility; i.e., tracking, remote control, and berthing of satellites brought to the station by a TMS for servicing. In addi- tion, facilities are required for removing products and resupplying new raw materials for space processing satellites, or film and tape for science and applications satellites. Assembly facilities are somewhat configuration-dependent, but include things such as manipulators, EVA systems, jigs and fixtures, and checkout equipment. Attached mission modules levy design requirements for mechanical, electrical, and fluid interfaces; proper clearance and reach envelopes for Installation and removal; and special attitude or pointing constraints. The design of the permanent space station includes two basic tasks: the arrangement of the overall external configuration and the interior design of the pressurized modules. The external configuration must be developed with both engineering and operational needs considered, some of which seem at times to be in conflict. Design drivers include clearance requirements for orbiter safe docking including thruster plume effects and contamination con- trol; OTV and TMS launch and recovery; control dynamics; clearance for assembly and construction of other space systems; power generation and thermal control; pointing and viewing; antenna and attitude control thruster locations; and safety. Interior design involves crew size, total habitability optimiza- tion, crew station design, health maintenance facility requirements, waste management layout, lighting, eating facilities layout, and rec- reation and exercise requirements; also, floor layout, subsystems access for maintenance and repair, hatch size and stowage, noise abate- ment, and crew safety. Tradeoffs for subsystem selection, design, and development include electrical power generation, distribution, and storage; thermal con- trol; life support; environmental control; propulsion for attitude con- trol and altitude makeup; guidance, navigation, and control; communica- tions; and data management. This paper will explore the space station design process and show examples of reference systems selection and design. - 30 -

IAF-83-31 JAPANESE FREE-FLYING SATELLITES

Kyoichi KURIKI*, Makoto NAGATOMO* and Tatsuo YAMANAKA** * Institute of Space and Astronautical Science ** National Aerospace Laboratory

Concept study of energetics laboratory and IR bionocular telescope have been provided as candidate free- flying satellites serviced by NASA space station by Task Team of Special Panel for Space Station, Space Activities Commission (SAC) of Japan for direction of SAC's planning. The conceptual study of energetics laboratory consists of modules commonly or uniquely used for the experiments of Space Experiment (SPEX), Advanced Propulsion Test (APT), Space Radar (SRAOAR), Microwave Energy Transmission Technology (METT), Solar Array Deployment (SADE) and Space Laser (SLASER). The architectural options are complexes of tethered satellites, sub-satellites and free-flying Bus platform periodically serviced by Teleoperator. Bus platform is co-orbiting with and ahead of the space station.

Bus platform consists of electric power, thermal control, communication and data management, attitude control, berthing port, propulsion system and experimental equipment. Strawman time-phased missions are SEPAC, MPD/ION, COPREX, METRAS/MINIX, 2-D, TETHER and LAP in time period of 1991 - 2000. The mission periods are 2-6 years. Bus platform grows evolutionally.

IP observatory consists of two infrared telescopes and a common focal plane detection system. They are useful as a general purpose telescope as well as a high resolution interferometer. The telescopes are either cooled or non- cooled, but the detection system is installed in fully cryogenically cooled chamber. The cryogens are supplied by an onboard liquefier or by retrievable storage tanks. Telescope aperture is 1-2 m in diameter, primary F-ratio is F/1.5, Cassegrain F-ratio is P/10-15, Nasmyth F-ratio is F/20-30, span of the telescopes is 5-10 m, angular resolusion 300 micron is 30"-60" (single) and 5"-10" (double). Instruments are infrared camera (2-dimensional detector array and i-dimentional detector array for far IR), wide band photometer and polarimeter with full wave- length coverage spectrometers and interferometer. - 51 -

IAF-83-33 BUS PLATFORM OF SEEL K.Kuriki and M.Nagatomo Institute of Space and Astronautical Science H.Saito and H.Obara Mitsubishi Electric Corporation

abstrac_t Many Japanese missions inplemented with Space Station in 1990,8 require the use of free-flying platform. Most of these missions belong to the field of "Space Energetics", and are proposed to establish the technological basis of space enery exploitation and environmental welfare or more specifically the space power satellite (SPS). To implement these missions effectively, the develoment of Space Energetics and Environment Laboratory (SEEL) is proposed by Institute of Space and Astronautical Science (ISAS). SEEL is an experimental facility complex. It is a part of and receives various services from Space Station. In SEEL, Bus Platform Iβ the main facility and Teleoperator and sub-satellites are sub-facilities. Teleoperator is an unmanned on orbit eervicer maneuvarable by the tele-command from Space Station manned base. Sub-satellites are mission peculiar, and their configurations are various according to missions. Hide variety of space experiments related to the development of SPS can be done using SEEL.. These are basic experiments on delivery of microwave energy to the earth, transmission of energy between space stations, technical experiments on transportation, orbital traffic control, and- assessment of disturbance to the space environment, etc. Space-Energetics mission proposed at present are Space plasma experiment Advanced propulsion test Space rader Microwave energy transmission technology Solar array deployment Space laser Bus Platform is the main facility of SEEL and commonly used in these experiments. Bus Platform is an unmanned, mu 1 t- i -pay 1 oail platform which is detached from and <:o-.>ibi';: with Slpnce Station manned base. It is controlled and operated from Space . f> tat ion operations center which ts set up on npace Station manned base. Bus Platform consists <>f Service Mission Modules. Service Module is the central «ire of Bua Platform and performs all house keeping fiinntions '>f the entire Bus Platform. Mission Modules are attached to ttn- berthing porta of Service Module and accommodate mission ecm ipnitjn ts. Adoption of modular design enables on orbit replacement of equipments and provides flexibility to add IK-W technology as it matures.

When a mission is completed,the Mission Module is removed from Service Module and a new Mission Module is attached to it on orbit. Mission Modules accommodating large mission payload is attached to Service Module after undergoing assembly, deployment and check-out at Space Station assembly area. These change-out, maintainance and supply services nr*> performed by Space Shuttle in the initial phase and by Telooperntor after it becomes operational.

By its own nature, SEEL Bus Platform is required to capability of supplying Misson Module large amount of electric power. Implementing high power experiments on HMK Platform detached from Space Station manned base, makes possible the avoidance of interference with Space Station manned base .

Service Module and initial Mission Modules are delivered to the vicinity of Space Station manned base by a single :*

The orbital conditions are considered to be 400 thru 5O(M;»n altitude, at inclination of 28.5 thru 55 deg. Bus Platform attitude control subsystem has several control modes corresponding to inertlal pointing, narth pointing etc. Sparc Station operations center commands the specified mode. Orbital maneuver is also commanded from Space Station operations center. Communication link is set up only to lh» Space Station manned base. Communications are accomplished all through the Space Station manned base. Operation Ul"«» is 5 years, which can be extended to 10 years by the minor refurbishment after "> years. The longest, free-flying peritui without, service is 1 yesr. Propulsion subsystem nonslUiiifs a IHDIIUIC and is replaced once a year on regular basis. Fl'-ctrira) power subsystem provides mission payl oads viitj. 10kw of |iow")' under any conditions. Two ext.endabl e/r«'H.i »•• < -"I- - I «• p.iHdles with 10 two blankets each, generates maxsttrini j.«5w<.r of ISkwfUni,). Ha.-ti wing in the f u 1 1 y-px tended pos i ' i •••«, is ab'iiil. 'Vm I ong 8.6m wide. Tnitial Service Module ran B»ryic" H Mission - 33 -

IAF 83-39 OPERATIONS/SERVICING OF A SPACE BASED OTV ON A SPACE STATION 0. STEINBRONN E. HUJSAK J. MALONEY

GENERAL DYNAMICS CONVAIR DIVISION

Comparative studies of space based and Earth based reusable orbit transfer vehicles (OTV's) have until recently provided little Incen- tive to convert to space based operations. A main cause for this has been failure to recognize that for full benefit, a space based system must be designed for the space environment. Carry-over of ground launched vehicle design philosophies Into space based vehicles must be abandoned, the primary reasons being: 1) Space Shuttle cargo bay volumetric and dimensional constraints no longer bound the con- figuration; 2) Structural and propellent conditioning load penalties associated with ground launched vehicles are relieved; 3) Vehicle and subsystem complexities for loading, emergency dump, and safing are eliminated; and 4) Weight reductions are made possible by operation 1n space at reduced propellent vapor pressures. A second major consideration when addressing the economic benefits of a space based OTV Is recognition of the potential for low cost trans- portation of propellants to the Space Station for OTV use. This low cost transportation can be achieved through several means, Including scavenging of propellants from the Shuttle external tank on volume- constrained Shuttle flights, or through adaptation of the shuttle external tank to serve as an efficient bulk carrier of propellents. The former method provides essentially "free" propellent to the Space Station for utilization by an OTV. This paper primarily addresses the operation and servicing of an OTV on a Space Station. The design of a space based OTV 1s addressed to the extent necessary to allow adequate definition of the required operations. Section 1 addresses the projected benefits of a space based OTV (economic, performance, etc.) In a summary fashion. Design of a space based OTV, as addressed in Section 2, is governud by new sets of requirements, which allow a new vehicle configuration. A fortunate configuration outfall is the ease with which modular approachps apply, enabling flexibility in sizing of the vehicle simply by changing the number of propellent tanks. Modular approaches also enhance main- tainability, and can be accomplished in a manner that enables easy re- placement of manjor subsystems, and easy access for simple repairs or* adjustments. Section 3 addresses the operational and servicing aspects of the OTV on the Space Station. Servicing a space based OTV on a Space Station implies transferring the ground based operations currently carried out at KSC for upper stages into low Earth orbit. Previous studies have shown that approximately 55 people were required on the ground for the hands-on operation of turn- ing around a ground based OTV. Obviously, we must change the approach for a space based OTV if the full economic advantage of this approach is to be developed. Major maintenance issues are addressed which affect both the Space Station and the design of the space based OTV. A three level main- tenance approach and OTV modular construction will minimize the man- power required to actually turn the OTV around while attached to the maintenance berth. Using robotics for routine remove and replace operations will also minimize manpower requirements. Extra-vehicular activity (EVA) will be used for tasks where man's unique capability can be used to the greatest advantage. Additional major issues concerning the type of support required from the station can also be resolved by the recommended maintenance philos- ophy. An example is the type of maintenance facility for turning around the OTV. Four options are considered for the Space Station OTV maintenance facility; two pressurized hangar module configurations; non-pressurized shelter; and an option without a shelter structure. Efficient servicing of the space based OTV will integrate requirements for maintenance, fueling, payload installation and vehicle reconfigura- tion. Space Station facilities and OTV geometry are determined in a way that provides for accomplishment of activities by the most direct routes, without relaxation of safety. Section 4 concludes the paper by summarizing the benefits and operational capabilities of a space based OTV. Those areas are highlighted where further study and/or technology development is required to make efficient operation of a space based OTV possible and to fully develop Its potential. - 35 -

IAF-83-40 SATELLITE SERVICING FROM A SPACE STATION by K.J. Forsberg, H.T. Fisher, J. Thielen Lockheed Missiles & Space Co., Inc. Sunnyvale, California, USA

Support for satellite servicing operations, Including maintenance, repair, and resupply, is one of the major benefits to be provided by a Space Station. Many satellite systems have been, or are being, designed for on-orb1t servicing from the Shuttle; examples are the Solar-Maximum Experimental satellite, the , and the Advanced X-Ray Astronomical Facility. The space Station offers a more cost-effective base for routine scheduled servicing for appropriate missions. Major repairs, refurbishment, and equipment update may be done at the Station as a more energy efficient and cost effective alternative to the present concept of satellite retrieval by Shuttle and return to ground for major operations. This paper focuses on two Issues: orbit mechanics considerations for space based operations, and design considerations for typical on- orbit servicing activities. Both the promises and limitations of space based activity must be thoroughly understood before the Space Station can be properly designed to achieve its ultimate potential. Operations from the space station are of two basic groups: onboard and remote. In addition, there are health and maintenance activities on the station itself; operations include docking maneuvers, stage assembly for orbit transfer vehicles (OTV), interaction with payloads mounted on or tethered to the space station, construction and assembly of very large payloads in an attached mode, and spacecraft servicing at the station (as a complement to remote servicing). Remote operations include servicing and support of various space operations for four categories of free-flying spacecraft. First, satellites with the same inclination, orbit plane, and phasing as the space station and within a few miles of the station altitude, are readily accessible at all times and line-of-sight communications and control are possible. This first category includes the concept of free-flying clusters that may contain production facilities for material processing In space or free-flying platforms for various scientific experiments. The second category covers support of satellites in nearby inclinations (within 15 deg from the space station inclination), with the restric- tion that orbit transfer be made at nodal coincidence. Bounds are provided by the OTV capabilities and payload size. - 36 - The third category involves orbit transfer from the space station to any satellite in low earth orbit (LEO). The delta V required for a roundtrip maneuver will reach about 30,000 ft/sec, which could require a prohibitively large quantity of propellent unless advanced electric propulsion systems are used. Thus, for early station opera- tions, satellites in this category will likely be serviced by one-way missions only. Also, station-baserf .-Kiisions in this category should be restricted to critical activities that warrant the energy expendi- ture, such as the Space Shuttle rescue mission. The support of geosynchronous earth orbit (GEO) satellites is also possible from a space station. In fact, the energy to reach GEO is less than that required to support LEO satellites at non-optimum transfer times, since a large plane change from one LEO to another requires a 3 burn maneuver with apogee over twice GEO altitude. While all of the above categories of space based operations are important to establishing requirements for and configuration of a space station, misconceptions seem to have developed about LEO satellites servicing from a station. Often, it is not recognized that the interval between nodal coincidences for a satellite and a station in a 28.5-deg orbit will range from 50 days for a high altitude satellite to several years for a satellite at an altitude near that of the station, thereby significantly limiting opportuni- ties for minimum energy transfers from the station. Thus, this paper will concentrate on the second and third categories of remote operations discussed above. In the design of satellites for servicing, care must be exercised in selecting components for replacement on orbit. Trade studies on reliability versus maintenance costs are key in this decision process. Orbit replaceable unit (ORU) size and complexity must be traded against the number of spares and amount of special test equipment required. Simple ORU configurations with only a few components will reduce the individual ORU cost but increases the number of different ORUs required in inventory on-orbit. Larger ORUs with more components are more expensive, but simplify the inventory problem. The proper choice will be based on the specific spacecraft design. Consideration of spacecraft servicing requirements must be given careful attention in space station early phases design to ensure that proper capability is developed for this important function. Equally important, however, is the need to design spacecraft to permit on-orbit servicing from either space station or Space Shuttle. - 37 -

1AF-83-45

Abstract SPACELAB - TEN YEARS OF INTERNATIONAL COOPERATION

By Michel Bignier Director of Space Transportation Systems European Space Agency James C. Harrington Director of the Spacelab Division National Aeronatuics and Space Administration Michael Sander Director of the Spacelab Flight Division National Aeronautics and Space Administration Spacelab is an outstanding example of a successful international cooperative program. ESA representing 10 European partner nations designed, developed, and paid for most of the Spacelab hardware and software, provided the first Spacelab to the U.S.A. at no cost and is assisting the U.S.A. in Spacelab operations. Europe for the first time is now directly involved in manned systems. NASA representing the U.S.A. initially defined the concept and the requirements for Spacelab, assisted ESA during system development, procured a second vehicle and will operate both of them with the Space Shuttle. The U.S. financial commitment to the Spacelab system not counting payloads or follow-on missions is substantial, although only one-half that of Europe* s.

The paper briefly reviews the events leading to Europe's decision to develop the Spacelab as part of the Space Transportation System, and also the three formal international agreements which define the roles and commitments of the U.S.A. and European partners in this cooperative venture. The paper also describes, briefly, accomplishments and plans in the three principle aspects of the program, i.e., development, operations and utilization. It also identifies the particular activities and areas where ESA and NASA are supporting each other. The paper ends with some conclusions on international cooperative programs in general and the particular qualities the teams must demonstrate to accomplish a successful joint program. IAP-83-48

?JJLJ OF NASA SPACE STATION SYSTEM ACT IV]X J FS

E. Lee Tilton, III E. Brian Pritchard NASA Space Station Task Force

NASA is presently conducting a planning activity that will eiwihle the United States Administration and the Congress tn make an informed decision on whether the United States should develop a Space Station System as the next major initiative in space. The Space Station System is viewed as an evolutionary system nu«l* up of manned and unmanned elements that serve specific user needs. Tin long term growth of the System and the Introduction of new capabilities and technologies to meet a maturing use of space are

1) A research facility for science, applications, and technology development which may Include attached laboratory modules, co-orbiting laboratories and a test range.

2) A transportation node serving as a base for both low energy and Mpli energy orbital transfer vehicles. This includes propellent storage and handling facilities, spares storage, payload/transfer vehicle mating and preparation facilities, and paylood collection and preparation for return to Earth via Shuttle. -39-

3) A satellite servicing/assembly facility which serve* at a baae for routine servicing (eg: fluids resupply, instrument calibration* preventive maintenance), aatellite repair (eg: aodttlc or component replaceaent), aasetibly of satellite elements and checkout. 4) An observatory for terrestrial, solar, and astronomical viewing which may Include both attached and co-orbiting elements. The accommodations discussed are just the beginning of a continuing Space Station System definition process that will continue for at least two additional years to produce a low risk, carefully conceived • development plan that would ley the gtouadeerfc for th» initial spe capability in 1991 and, thus, the framework for the evolution of thj System. •'...' Just as the physical definition of the Systea is belmg planned in great detail, so are the potential management aspects of the progtea. All aajor past NASA prograas are being reviewed to determine level of success of the aanageaent techniques employed. In addition• mew aenage- aent ideas froa NASA, industry, and abroad are being aaaessed as poten- tially applicable to a Space Station System Frograa. The following management areas have been identified thus far for careful attention and planning. User requirements must be considered froa the beginning of the planning effort. Failure to do this in the past has resulted in leas - than friendly user Interfaces further resulting In costly operations and schedule slips. Utility of the Systea is paramount, perhaps being analogous to an industrial park, where profitability to the operator and productivity for the user are aeaaures of success, . The growth and evolution of the Syetsm must be such that new technology can be introduced at all levels when appropriate. This would challenge traditional design methodologies and require development of apace age aaintenance and aystea integration techniques* A closely related area of concern is that of Syatea Operations. Philosophies of operation must serve the user. Levels of Systea autonomy would be different from current systeas and aay evolve as new subsystems and capabilities are introduced. Commercialization of certain aspects of Systea operation, ownership, services and access must be considered and appropriately instituted. Such unprecedented actions would surely require government and industry cooperation at the national and international levels In innovative ways not currently practiced. Finally, the application of organisational structures, relationships end contracting methodologies must serve all of the above needs. Various changes in past and present methods are being evaluated through discussion with potential program participants and review of past and current program successes and failures. Development and operating coats will be of critical Importance and'low cost development, construction aw! aanageaent techniques are being sought and challenged Including the costing practices theaselves. IAF-83-49 The Utilization of Spacelab Roy C. Lester National Aeronautics and Space Administration George C. Marshall Space Flight Center

The transitJon of the Space Shuttle to operational readiness has inaugurated a new era in space. The Space Shuttle com- prises the National Aeronautics and Space Administration primary transportation system into near-earth orbit and provides the scientific community with a major new capability to send a variety of scientific instruments into orbit, to operate them under manned or automated control and to return them to the investigator. Included in this transportation system is the Spacelab which has been developed by the European Space Agency under an international cooperative agreement with the National Aero- nautics and Space Administration. This paper describes the general characteristics of Spacelab and discusses its past, current, and planned utilization.

To date, the major emphasis has focused on the development of the hardware and on the first two flights whose primary purposes are the engineering verification of the Spacelab systems and to demonstrate the capability to use these systems to conduct scientific investigations over a wide variety of scientific disciplines. The experience gained from planning these early flights has shown that mixing disciplines with conflicting requirements on the same flight significantly compounds the complexity of the mission and leads to an inefficient use of the spacelab and shuttle resources.

To minimize the complexity and to better utilize the Spacelab and Shuttle capabilities, a new utilization concept is being developed. This new concept, called "Dedicated Discipline Labs," involves the grouping of scientifically compatible instruments into an appropriate carrier and regularly flown at intervals on the order of six months to two years. The design approach of the Dedicated Lab allows for the evolution of individual instruments and the addition/deletion of instruments without major redesign of the entire payload. Inherent in the concept is the cost advantages of leaving the payload integrated with the spacelab hardware between flights. The long term goal is . to evolve the Labs into low earth orbiting facilities for space stations. IAF-83-50 A Space Station Experiiient on Large Antenna Aaseably and Neasure«ent

Takashi IIDA», Yoshiaki OHKAMI**, Seishlro KIBE**, Ken1ichi OKAMOTO*. Hajime KOSHIISHI»», Masao NAKA", and Hiromichi YAMAMOTO" 'Radio Research Laboratories, Ministry of Posts and Telecommunications 2-1 Nukuiklta-machi, 4-chome, Koganei-shi, Tokyo, Japan 164 '•National Aerospace Laboratory, Science and Technology Agency 1880 Jindaiji-machi Chofu-shi, Tokyo, Japan 182

A large antenna in space is a key device for future remote sensing technology as well as space communications. The antenna, having a large epprtur* than the fairing, of the transportation vehicle, must be de- ployed or assembled in space. Various types of deployable antenna are realized or proposed so far. Meanwhile, the assembly antenna in space could accommodate future requirements of both high frequency and large aperture. This' is why it has primarily a fairly accurate reflector sur- face. Although the Operator-controlled manipulators or the extravehicu- lar activity are required for assembling such an antenna in space, the Space Station can offer such operations. This paper proposes an experiment, on assembling a large antenna at the P["iri> Htution and discusses a realizable procedure of the experi- ment. The objective of this experiment is that a large antenna of 10 in d lawyer i« assembled in space and at the same time the problems occur- r«»rt It thp iisfinmbling process are clarified by conducting following

H) Assembly of test articles by manipulators. (11) Measurement of characteristics of the assembled antenna. a. Mechanical performance measurement: (a) Surface accuracy, (b) Thermal distortion, (c) Characteristic frequency, and

IAF-83-53 JAPANEASE MISSION MODEL FOR SPACE STATION

Sh1gem1ch1 Sonoyama*, Makoto Nagatomo** and Tatsuo Yamanaka** * National Space Development Agency ** Institute of Space and Astronautical Science *** National Aerospace Laboratory Missions relevant to NASA space station study have been collected by Special Panel for Space Station, Space Activities Commission (SAC) of Japan, and by Space Station Symposium held by four organizations responsible for Japanease space development activities In October 21, 1982. Classification of mission Items Into disciplines and the mission requirements have been prepared to study preliminary concepts which provide focus and direction for SAC's planning and general Informations for mission proposers, user communities and potential users of the space station how their experiments would be Incorporated Into the space station program. Collected themes are classified Into seven disciplines, I.e., Science Observation, Earth Observation, Communication and Navigation, Material Processing, Life Science, Space Technology Experiment and Subsystem. Each discipline Is classified Into several sub-disciplines. Science Observation 1s listing radio, Infrared optical, solar- terrestrial X-ray and Gamma-ray observations. Contents and methods of the proposed missions are diverse over wide areas. Common requisites of them to the station or platform are summarized as follows. (1) High attitude stability. The requirements are varied from 1 degree to 10~z arc-seconds. Most of them are within 1 arc- second. This suggests that accomodation on an Isolated platform 1s preferable. (2) Low contamination, thermal emission from the structures of MSS Is very hampering for Infrared observation. That of small dust particles hanging around the MSS would be easily detec- ted as spurious stars and become annoying Images for observation. Gases evaporated or exhausted from MSS would be absorbed on the cold telescope mirror and fatally degrade their reflectivities. (3) Infrared, submilUmeter and gamma ray observations require to be supplied cryogens such as liquid helium or liquid nitrogen for cooling the detectors and the Instruments themselves. (4) Electric power. Most of the missions require relatively small electric power for operation, I.e., less than 1 Kw. Earth Observation Is listing weather radar, Lidars, real time report- Ing system on ocean conditions, laser ranging and land observation. General characteristics of the proposed missions are categorized Into the following common requirements. (1) Advanced earth observation experiments. LSS sensors such as large antennae, lasers and onboard data processing are advanced technologies. Man-tended space experiments are proposed to develop more easily these technologies In MSS rather than by means of conventional satellites. (2) Evaluat- ion of sensors. Evaluation of sensors prior to flight is difficult. Utilization of MSS is beneficial. (3) Real Time Reporting System on Oceanic Conditions 1s expected to realize systematic fishing con- trolled by scientific management of oceanic resources. (4) Meteorol- ogical, geodestic, plate tectonic and earthquake forecasting experi- ments are proposed. Most of them are attached to MSS. Specialists- tended are required. Material Processing describes the activities 1n the three sub- disciplines such as basic material science, space processing experi- ment and commercial space processing test. Basic material sciences are fluid dynamics, physical chemistry, thermodynamics and statistic?.! dynamics, crystal growth and physical metallurgy. Unique equipments are required. Space processing experiments are relevant to homogeneous - fine-structured electronic materials, single crystals, ceramics, alloys, composites and organic materials. Common equipments such as furnaces are required. Commercial space processing tests are relevant to compound semiconductive single crystals, si-ribbons, optical fibers and alloys. Various unique equipments and large electric power are required. Answers to questionnaire sheets from twenty-two current researchers relevant to micro-gravity give priority to space process Ing experiment in MSS. Life Science describes biology experiments, space medicine, controlled ecological life support system and bio-processing experiments. Biology experiments in an artificial gravity field are major proposals. In space medicine, cardiovascular system, musculoskelted metabolism system, bloody and Immunological study are major. Many experiments relevant to controlled ecological life support system are proposed. Bioprocessing experiments require free-flow electrophoresis, cell cultivator, centrifugal separator, chematograph, freezed dry unit and freezer. Space Technology Experiment has four goals, i.e., (1) to support Japanease space station mission activities, (2) to develop LSST, (3) to provide high power system and (4) space system verification tests. Some of missions categorized 1n Earth Observation and Communication and Navigation are Included in the Space Technology Experiment. Concerned subsystems of the space station are attaching pressurized and exposed elements, subsatelUte type platforms, a teleoperator, an orbital transportation system and logistics. XXKIVth IAF Congress Abstract to the paper:. IAF-83-54 Authors: H. Ley; H. Sax Title: "European Utilisation Aspects for a Space Station"

In order to be prepared for a later decision upon European participation In U.S. Space Station activities, the results of the ESA-study-titied "European Utilisation Aspects of a U.S. Manned Space Station" - will be presented. In addition the results are extended to manned and unmanned space sta- tion. The following main Hems will be discussed: - Identified candidate payloads and benefits for the disci- plines o Material sciences o Life sciences o Commercial processing o Space science o Space applications (Earth observation, communication) o Technology testing o Longterm new utilisation fields - Mission Identification o Orbit requirements o Resources requirements (technical) o Crew Involvement o Operational requirements (functional) • Impact on system architecture o Manned, man-tended, unmanned platform o Transportation* logistics, service vehicles - Assessment of utilisation potential of possible european elements - Programmatic synthesis and time-phased european mission scenario IAF-85-57

International Experimental Satellite Comaunication Systea

Authors: 7.L. Bykov, V. Libsch, B. Balabanov, J.Zygierewicz, J.Wt

Within the international cooperation program of the socialist countries "INTERKOSMOS" an experimental satellite communication system was designed for the research in propagation of radio waves at frequencies above 30 GHR and for the research of new methods of Information transmission. Bulgaria, Hungary, German Democratic RepnbJie, Poland, SoTiet Union and Ceechoslovakia take part in this program. She terrestrial part of this systea consists of facilities at the international measuring centre Dubna near Moscow and all member-countries of IHIEHKOSMOS also operate their own experimental stations. The experimental systea utilizes the "Loutch" satellite located at 53°Bf which carries a 14/11 SH* traasponder. In Dubna the main 12-metre antenna earth station is located which transmits experimental signal according to an agreed program. The down-link signal in the 11-GHe band is being received by receive-only station /2nd class type/ with 3- or 4-metre antennas. These stations provide long-term measurements of radio wave attenuation caused by precipi- tations along the down-link. Attenuation and depolarization measurements in terrestrial links in 11, 20 aad 30 QHE bands, using propagation along the projections of satellite links, complement the system. Along the aeasuring links, measurements of rain rate and other meteorological parameters are provided. She data from the measurements gained at the international center Dubua are processed by a computer and the results are periodically eraluated by the specialists from meabercountries. The introduction of the international experimental satellite system into operation represents an important contribution by "IKHSEOBIfOB" countries to the peaceful use of the * - 48 -

IAF-83-58 OVERVIEW OF NEW TECHNOLOGY FOR FIXED-SERVICES COMMUNICATIONS SATELLITES E. BERTENYI TELESAT CANADA

Telecommunications via satellite has become a routine commercially oriented activity. Space technology has matured over the years to the point where the design and implementation of cost effective satellite communications systems is now a relatively straight-forward engineering task. There is nevertheless an ever present demand for more, cheaper and better RF channels, and more cost effective systems. This, and the growing need to more effectively utilize non-renewable resources such as frequency spectrum is the driving force behind the efforts of satellite system designers to apply new technology to spacecraft design. The underlying theme of this paper is the need for co-op- eration between development of technology and the design- ers of communications satellite systems. The paper re- views how the application of new technology could improve the overall performance of fixed services communications satellites, and consequently what areas of new technology are of particular interest. A starting point is a better utilization of the on-board generated RF power. High gain narrow beam antennae, with beams shaped to optimize performance, promise not only a reduction of spacecraft primary power requirements but also a higher degree of frequency reuse capability. Array type antennae with distributed RF amplifiers might offer efficient beam shaping, electronic beam steering which could significantly reduce spacecraft attitude control requirements, and potentially high reliability with grace- ful degradation, particularly if solid-state RF amplifiers are employed. Interconnectivity between the coverage areas could be pro- vided by on-board switching, which would also improve sys- tem flexibility and could provide a capability for in-orbit system reconfiguration to accommodate changing traffic re- quirements. -49-

Inter-satellite microwave or laser communications links would further increase the flexibility of the space seg- ment by providing interconnectivity between areas served by separate spacecraft. They would also permit space segment reconfiguration to accommodate changing market requirements, 6r to alleviate the effects of a partial system failure. There are other areas as well, where the application of new technology would result in higher cost effectiveness by reducing the spacecraft weight or by extending the service life of the space segment. A fault tolerant on- board computer could provide a high degree of system flexibility by controlling on-board switching and system configuration in addition to efficiently performing the attitude and orbit control functions for dynamically com- plex structures. It could also provide on-board trend monitoring which promises a potentially higher space seg- ment reliability with early indication" of impending failures. Autonomous spacecraft operation could also be implemented to reduce the impact of temporary ground control interrupt on the service life of the spacecraft. Advanced electrical power storage devices promise lower weight, higher reliability and longer life. Advanced propulsion systems could significantly reduce the on- board fuel requirements. A brief description is presented of an advanced fixed service communications satellite to illustrate how the applications of new technology might influence system design in the next decade. - 50 -

IAF-83-59 ATHOS, AN EXPERIMENTAL TELECOMMUNICATION PROGRAM TO PROMOTE NEW PLATFORM AND PAYLOAD TECHNOLOGIES Didier Lombard - Centre National d'Etudes des Telecommunications Georges Delmas - Centre National d'Etudes Spatiales

. The ATHOS project has been developped by the OGF and the CNES in response to an RFP issued by the European Space Agency and will serve as a pay load in the qualification launch of the ARIANE IV launch vehicle at the end of 1985.

. This technology satellite project is intended on the CHIP hand to validate the Eurostar satellite platform, which is an advanced version of the European ECS/TELECOM 1 platform, particularly well suited to the new ARIANE IV launcher, and on the other hand, constitutes a natural application environment for the stiidle'. conducted at the CNET on future satellite telecommunications systems. . The Eurostar platform makes use of the most advanced technoin gies : carbon fiber structures, unified bi-liquid propulsion anil stabilization subsystem, ultra-light solar arrays, Nickel Hydrngpii used to accomodate a 1250 to 1800 kg overall spacecraft mass. . The payload consists of 6/4 Ghz and 30/20 GHz teleconmiinUa tions modules, a propagation module and technology packages.

The 6/4 GHz payload will be used for experimentation of transponders capable of generating a high power flux density OVPT the service zones. It consists of eight 36 MHz bandwidth transponders, using 16 Watt saturated power TWTAs, and a multi-spot beam antenna. In addition, 1t will give the opportunity of testing new device*, such as solid state amplifiers developed for ESA. The 30/20 GHz payload will allow for testing satellite telecom- munications system concepts and technologies In these new frequency bands, through field trials. It implements three 100 MHz transponders and a 4 x 4 microwave switch matrix, intended for evaluation nf the on-board switching concept. In addition, the payload comprises a dedicated module for propagation experiments in the 20 GHz, 40 GHz and 90 GHz frequency bands. -51-

IAF-83-61

POWER CONDITIONING SYSTEM OF AN INTERNATIONAL AMATEUR RADIO SATELLITE

Richard Redl Antal Banfalvi Technical University of Budapest P.O.Box 91, Budapest, H-1502, Hungary The main goal of the AMSAT Phase III type spacecrafts is to facilitate communication among the amateur radio people all over the world. However, the experience gained by the novel technological solutions used in the design, construction and operation of the spacecraft (and of the ground terminals, too) is almost as important for the par- ticipants as the main goal, itself. The Amateur Radio Club at the Technical University of Budapest was responsible for the so-called BCR unit of the Phase IIIA, B and C satellites. The BCR units, each of which comprises a fully redundant battery charge regulator, digital-to-analogue converters as interfaces between the on-board computer and the regulators, an extra 10 V regu- lator for all spacecraft logic (including the computer), telemetry circuitry, etc, was designed and manufactured by the volunteers of the Radio Club in Hungary. Guidance and supervising was provided by AHSAT-DL, who had previous experience with similar energy systems.

Several interesting novel system-level and circuit-level solutions are used in the power handling subsystem of the spacecraft. E.g. maximum power-point tracking principle is applied for quick charging of the battery under com- puter control and with power-flow interrupting possibility in order to prevent battery overcharge. At interrupted power flow there is virtually no power loss in the main regulator and in the summing diodes of the solar arrays. The logic power supply, while maintaining hot redundancy together with a separate, remotely located regulator on board, can operate down to 0.3 V input-output voltage difference at 10 V output and at very high efficiency due to a special lossless base drive circuit.

Currents are measured and data are sent to earth from nine branches of the BCR circuitry. The current telemetry system operates with zero dc voltage drop in the main current carrying routes and with negligible power drain - 52 -

of the necessary active circuits. Possibility of connecting an auxiliary battery in the system whenever the main battery fails or degrades is also included in the BCR. Switch-over from the main battery to the spare one takes place by latching type re- lays. Also latch relays provide switch-over at the input of the two regulators which are to be used with cold redundancy for battery charge.

Fuses provide separation of filter capacitors and semiconductor devices from the main unregulated bus at catastrophic failures resulting in shorted circuit for the bus. Some of the key technical parameters and features of the system are as follows: - average input power from the solar arrays: ~40 H - batteries: NiCd, main battery capacitance 6 Ah, auxiliary battery capacitance 4 Ah, re- dundant "cold storage" spare concept - array voltage, battery voltage adjustment under computer control, allowing exact temperature com- pensation

- power conversion efficiency of the battery charge regulator (including summing diode losses): ~88 % - power conversion efficiency of the logic power supply: -89 %,at 10 W, ~79 % at 2 W output power level

- dropout voltage of the logic power supply: -O.3 V at 2 W, "0.6 V at 10 W output power - mass: 1280 g - dimensions: 235x239x40 mm The paper will introduce the basic philosophy of the applied battery charge regulation principle which is be- lieved to be not widely known. Also the numerous novel circuit solutions used in the BCR will be presented. At last the most important technical parameters and the lightweight and inexpensive construction will also be shown. - 53 -

IAF-83-62 L-band Transistor HPA with Adaptive Bias

Y.Hase, S.Miura and H.Morikawa

Radio Research Laboratories, Ministry of Posts and Telecommunications 2-1, Nukui-kitamachi 4-chome, Koganei, Tokyo 184, Japan

The Aeronautical Maritime Experiments System (AMES) for domestic satellite communications of aircrafts and small ships will be installed in Engineering Test Satellite-V (ETS-V), which is scheduled to be launched in 1987 with H-i launch vehicle by National Space Development Agency of Japan (NASDA). In the system, C-band frequency for earth-satellite link and L-band frequency for satellite-aircrafts/ships link are used.

L-band High Power Amplifier (HPA) of the AMES transponder is under development by Radio Research Laboratories (RRL). The last stage of the HPA consists of 20W-class transistor and its efficiency is expected to be more than 20*. In the case of SCPC used in the AMES, the HPA must be a linear amplifier, otherwise a large sum of Inter Moduration (IM) products generated in the HPA would make interference w.ith the communication channels. Therefore C-class amplifier with high efficiency can not be used. However, A-class or AB-class amplifier with good linearity has poor efficiency and is not suitable for large power transponder.

From this point of view, an adaptive bias method is adopted for the HPA. With this method, both high efficiency and good linearity can be obtained over a wide range of input power since the bias current of the transistor is adjusted automatically according to the input level of the amplifier. That is to say, the transistor operates almost in B-class at low level and in C-clasa at high level. Th« efficiency of the adaptive bias amplifier is able to reach the same as that of C-class amplifier.

The HPA has more than 60 dB of gain. It consists of six stage transistor amplifiers, of which the initial four operate in A-class because of their low handling power. The last two transistors operate in adaptive bias. The circuit of the adaptive bias amplifier is shown in Fig.l. By adjusting bias voltage and resistor, we can obtain the beet linearity. Data of the Bread-Board Model (BBM) of the HPA which was already made are shown in Table 1. We will probably be able to reduce IM to -20 dB or less if the efficiency is reduced to about 20%. Proto-Flight Model (PFM) of the transponder is expected to be assembled in 1985.

Table 1. Data of the BBM of the HPA

Frequency 1543 MHz + 5 MHz Maximum output power 43 dBm Gain 63 dB Efficiency 27.6 % at 43 dBm output (Efficiency of power supplies is included) Weight 1.7 kg 3rd IM (2 carriers) -17 dB to carrier level (2 dB output back-off) Pig. 1. Circuit of the adaptive hi a?; o- T O O o o 777771 J Ce L Vcc

777777 > Re

Vad

77777 - 55 -

IAP-G3-64 THE EFFECTIVENESS CASCADE MAJORITY COMMUNICATION SYSTEM B.V. Roshchin, R.R, Mazepa Intercosmos Council, USSR Academy of Sciences How in satellite communication systems linear meth- od such as frequency-division multiplex, time division multiplex and waveform-division multiplex are used. From the above method the beat effectiveness *f the using frequency band and satellite tranemitter-relay po- wer have the time division multiplex. Yet the work organization of satellite communicati- on system v/ith non fixed channels meets some difficulties, Among non linear methods of multiplexing the most interest has the majority multiplexing. Using this method or the method of time-di.vision multiplexing the multiple syRiials has the minimal peak factor. So the satellite trersm-l' fcer-relaypowe r can be ueet! effectively. The cascading can be uuod for organization overflow majority multiplexing dividing compressed channels In groups including J or 7 cli'Aimola in each. In this article iJio 'iffectiverieas pf cascad majo- rity multiplexing ia ren-mrchcd. It is shovm that reducing of activity of multiple- xing channels has led to the automation increasing ef interference killing fnalures without any changes in algorithm of channel S'-'pavafcion. Caecad majority multJplexing is the method of mul- tiplexing with fixed channels that have the moat simple procedure organization of multiplexing. IAF-83-66 ADVANCED SATCQM: STATE-OF-THE-ART TECHNOLOGY IN OPERATIONAL SERVICE John Clark, John Keigler, Brian Stewart • RCA Corporation

ABSTRACT

Channel demands on the RCA Americom domestic satellite communica- tions system have continued to increase rapidly since the first launch in 1975. After deploying four of the firet generation 24-channel C--haw1 spacecraft, Americom introduced an advanced satellite design in 1982 which has more than twice the traffic capacity of the original series plus spacecraft bus improvements that simplify operational control an well as extend mission life. With increased traffic capacity and longet life, the advanced SATCOMs continue their competitive reduction of cost per satellite circuit per year.

The applications of new technology to are in both the com- munications payload and the spacecraft bus. A new high-gain, shaped- beam antenna increases the gain over the service area while retaining the frequency reuse scheme of overlapping, cross-gridded reflectors pioneered on SATCOM. On SATCOM VI (now designated SATCOM I-R) a mode B» reconfiguration of the antenna beam is commandable on-orbit to respond to post launch changes in the service area and/or assigned longitude station. In addition to improved channel frequency response from Hgbi weight elliptic-function multiplex filters, the replacement of travelling wave-tube amplifiers by solid state power amplifiers in the transpnnilpr provides improved linearity and liigher reliability for long life operation.

Maintaining the general arrangement of a rectangular box structuti? and deployed solar arrays of the original SATCOMs, the advanced design spacecraft contains new technology in each subsystem. With the transfpi orbit-mass Increased from the original 900 to 1250 Kg and solar array area increased from 7 to 12 m-2, the advanced design is still compatible with the volume constraints of the Delta fairing, with a structure nta«;s ratio of less than 62 of lift-off weight. Refinements of attitude control logic have reduced station-keeping operations for orbit inclination and longitude drift control to simple START/STOP command*, and introduction of high-specific-impulee electrically heated thrustero on SATCOM I-R extends the mission life to ten years.

Early application of state-of-the-art technology to operational programs Is continuing by RCA Astro-Electronics on other progr-uas as well ae SATCOM. Simplified multiplexer and antenna feed networks arc being introduced to reduce weight, while lover noise figure receivers and higher power transmitters will further improve the receiver - 57 -

of nerit, G/T, and the equivalent isotropically radiated power. Coaaandable spacecraft roll offset will permit in-orbit antenna pointing optimisation, nickel-hydrogen batteries are being applied to realize reduced weight per ueeable ampere-hour, and heat pipes are being used to spread the thermal dissipation from higher power transponders. -58-

TAF-83-67 A Control method of Antenna Pointing Error Due to for a Spin-stabilized Satellites T. IZUMISAWA, M. SHIBAVAMA and S. SAMEJIMA Yokosuka Electrical Communication Laboratory Nippon Telegraph and Telephone Public Corporation 1-2356 Take, Yokosuka, Kanagawa, Japan Abstract The orbital inclination of a geostationary communications satellite must be kept within a specified narrow range not only to simplify the tracking equipment of a ground station antenna but also to maintain the satellite antenna pointing accurately to the specified narrow coverage. However, the orbital plane of a geostationary satellite inclines at a rate of approximately 0.8 degrees per year, due to lunar and solar perturbations. Therefore, a North-South (N-S) station keeping maneuver must be performed periodically to keep the orbital inclination within an allowable range.

The fuel consumption necessary to perform the N-S maneuver is more than 30 times that of the East-West (E-W) and Attitude maneuvers, and accounts for majority of the total fuel consumption. Therefore, the life span of a communications satellite has been virtually limited by the amount of the fuel to control the orbital inclination. After most of the fuel is consumed, the orbital inclination grows up out of its range and the antenna pointing error will exceed the allowable limit.

The antenna pointing error due to the orbital inclination can be separated into two components: one is the North-South error (N-S error) and the other is the East-West error (E-W error). Under normal operating conditions in which the satellite spin axis is kept perpendicular to the orbital plane, both errors show diurnal sinusoidal variation. The N-S error reaches its maximum when the satellite is located at its highest and lowest latitude positions in the orbital plane because of the satellite roll error. The E-W error reaches its maximum when the satellite passes through its ascending and descending nodes because of the satellite yaw error. The magnitude of these errors depends on both the latitude of antenna coverage center on the earth (bore site position) and the orbital inclination. The N-S error can be minimized by changing the satellite spin axis toward an optimal direction from nominal orbit normal direction. The E-W error can also be reduced by adjusting the antenna despin bias. - 59 -

In this paper, algorithms to control the attitude and the antenna despin bias of the satellite are described. Experimental results on antenna pointing error correction, using the Medium Capacity Communications Satellite for Experimental Purposes (CS), are also given. The overall C/N_ (carrier to noise power density ratio) for a K-band (30/20GHZ band) satellite link was measured for 24 hours, by setting the satellite attitude and the antenna despin bias in the following three conditions. In the first case, the attitude was maintained at its nominal position which is perpendicular to the orbital plane and the antenna despin bias was fixed to its nominal value of zero degrees. In the second case, the attitude was adjusted optimally with the antenna despin bias fixed to zero, in order to remove only the N-S error. In the final case, both the attitude and the antenna despin bias were adjusted to minimize both the N-S and the E-W errors. When the measurement was performed the inclination angle of the CS was 0.8 degrees. Diurnal Co- variation of 0.8 dB peak-to-peak in the first case was reduced to 0.6 dB in the second case, and to 0.2 dB in the final case. These results showed good coincidence with the computer prediction results. - 60 - REFERENCE NUMPBR OF PAPER IAW-β 3-68

AM OPTIMAL ACTIVE CONTROL STBTEM WITH FOURIER TRANSFORMED PROCESSED STATES FOR FLEXIBLE STRUCTURE IN SPACE by Achille Danesi Aerospace Department, Rome University - Italy A new strategy in controlling the modal shapes of L.3.3.(lar- ge structure in space) components is presented in this stu- dy. An active low authorithy modal control system, consisting of a discrete number of independent servo system units di- stributed along an L.S.3. flexible cantilever columns sup- porting RF radiators, is provided to measure and control the local deformations in order to obtain a modal shape ehich results in an acceptable pointing error for the RF radiators. Each servo system unit is conceived as a compact low weight- small size closed loop digital control unit in which a mo- dal sensor, a force-mass actuator and a microprocessor are the costituent parts} the microprocessor in each eervo loop is a real time-high speed FFT dedicated processor computing, at discrete time intervals, the structural mode frequency spectrum from the time functions measured by the displace- ment and rate sensors* In the same time slot the correspon- dent spectral error in respect to a desidereti frequency spectrum established by the designer and stored in a micro- processor FROM area, is computed. The inverse fast fourier transform, computed with the same algorithm employed for the FFT calculation, applied to the spectral error function yields, in the time domain, the digital information driving the digital actuator in its control effort in the range of - 61 -

the frequencies which is recognized to be dominant for the frequencies which is recognized to be dominant for the application at hand. In this study particular emphasis will be given to the spectral error digital filtering pro- blem in the aim to obtain an high precision model-follo- wing process resulting in a high pointing accuracy* Follo- wing an introduction stating the problem, the fundamentals on the control strategy adopted are presented and the ac- tual implementations is described. The modal shapes obser- ved as a result of digital simulation with and without the active modal control are presented and the comparative ef- fects on the pointing accuracy are discussed particularly in respect to the digital filtering solutions adopted in the design. - 62 -

IAF-83-69 Radiation-Proof Satellite Technology

V. Poulek Czech Technical University Prague, Czechoslovakia

Solar arrays are at present the most advantageous sjurce of power for artificial satellites. In spite of it even this source has some considerable shortcomings. An important problem is the damage of solar arrays caused by corpuscular radiation, whether it is by cosmic radiation or nuclear radioactivity. While the other electronic parts can be effectively protected with protective covering, solar arrays, which form the largest part of the satellite cannot be protected in this way. It practically means that during the ten years of the service life of the satellite the solar arrays on the present communication satellites lose about one third of their performance becauce of cosmic radiation. Moreover, if the satellite was affected by nuclear radiation, these losses would be even greater and might completely stop the satellite working / e.g. damage after the Starfish nuclear teat in 1962 /.

The solar arrays are damaged mostly by high energy charged particles. This damage, however, can be removed - 65 -

by laser annealing. Regeneration tests of the damaged solar arrays were carried out successfully in earth laboratories.

The author proposes to place a laser equipment on the satellite to regenerate the solar arrays directly in orbit. Especially advantageous is the application of the laser in spin stabilized satellites. Since the solar arrays of this type of satellites are placed on the spinning covering of the satellite, a deployable beam placed on the stabilised platform can be constructed, equipped with the eliding laser device which will irradiate rotating surface of the satellite. During each revolution of the satellite, the laser placed on the stabilized platform will irradiate a narrow strip on the periphery of the satellite. By gradu- ally shifting the laser device from the upper end of the rotating covering to the bottom end, the whole surface of the solar arrays will be irradiated in certain time* The efficiency of the regenerated arrays can reach 95 * of the initial performance*

The regeneration device will be controlled and powered fully independently* Also, the sise of this device and its weight will require no changes of the satellite construction nor the change of the necessary launcher. Therefore, it would be possible to add this device to various types of satellites, even to those whose constru- ction did not originally take account of using such a device* - 64 -

IAF-83-71 INITIATION OF BROADCASTING-SATELLITE SERVICE IN THE UNITED STATES OF AMERICA John F. Clark RCA Corporation P.O.Box 432, Princeton, New Jersey 08540, U.S.A.

ABSTRACT

This paper traces the evolution of the U.S. Broadcasting-Satellite Service (BSS) systems with emphasis on the explosive developments which have occurred since the 1981. International Astronautical Congress in Rome.l In October 1981, seven additional proposals to provide direct BSS (or DBS) service to individual dwellings were accepted for filing by the Federal Communications Commission (FCC). This made a total of eight such proposals which had been accepted for filing through 1981. Their common purpose was to provide DBS service to viewers in the con- tiguous United States (CONUS), and to at least parts of Alaska, Hawaii, Puerto Rico and the Virgin Islands, by a system which is economically viable, supported entirely by some combination of subscriber and/or advertiser revenue. These systems are described in some detail in Reference (1).

The FCC established an Advisory Committee in 1981 to assist in its preparations for the Region 2 Administrative Radio Conference (RARC) which was convened on 13 June 1983 to plan the BSS In the Western Hemisphere. The Advisory Committee completed its initial assignment and reported to the FCC in Hay 1982.2 The following quotations are contained In the Executive Summary:

"DBS will come to pass in more than one country within this decade. It can and should come to pass in the United States in this decade. These...convictions (are) based on our recognition that the tech- nical foundations of DBS are now solid...(We) list three of the most significant outstanding nonregulatory challenges: to develop space-qualified high-powered (several-hundred-watt) satellite travelling-wave-tube amplifiers capable of reliable operation for seven to ten years; to design and mass-produce low-cost (a few hundred dollars, Installed) reliable DBS home terminals which produce high-quality TV; to provide programming sufficiently

1. Clark, J. F., Planning for the Broadcasting-Satellite Service in the United States of America, Space, Mankind's Fourth Environment, L. C. Napolitano, Editor, Pergaaon Press, New York, 1982, pp. 169-176.

2. Clark, J. F., Chairman, Final Report of the Advisory Co—ittee on Preparations for the ITU Region 2 BSS Planning Conference,14 May 1982. - 65 -

distinctive and attractive (in either standard or [high-definition television] HDTV format) to develop an economically viable market share. These challenges...are arranged in ascending order of difficulty...(The) first two are well on the way to solution. The third is beyond this Committee's purview..."

In July, 1982 a joint two-week RARC-83 Conference Preparatory Meeting (CPM) of CCIR Study Groups 4, 5, 9, 10, and 11 concluded its hectic but productive sessions. The ranges of values of the key down- link planning parameters selected by the CPM include those recommended by the FCC Advisory Committee in every case. Important examples include: 18-24MHz bandwidth, 53-60 dBW equivalent isotroplcal.lv radiated power, 6-10 dB/K home terminal receiver figure of merit (C/T), and 12.5-14.5 dB carrier-to-thermal noise ratio (C/N). The perception that RARC-83 preparations were proceeding smoothly was only partly correct. At the CPM, the U.S. position tended toward the higher values of power and C/N, and the lower values of G/T, while the Canadian position tended to the opposite ends of the respective ranges. These positions are not econom- ically illogical because of the high U.S. population density compared to that of Canada.

Following the 1982 CPM, the FCC asked its Advisory Conmitee to review the conclusions of the CPM. The most significant new Committee findings were in the areas of home terminal antenna reference pattern, protection ratio templates, and feeder link planning parameters. Specifically, use of modern offset-fed home terminal antennas less than 1 m in diameter can permit orbital spacing as small as 10° between sate- llites serving adjacent service areas, with adequate protection margins against Interference.

In the fall of 1982, the FCC granted all eight applicants construc- tion permits conditioned on the outcome of RARC-83. At this writing (27 June 1983), the Satellite Television Corporation (STG) Is the only applicant to have signed a contract (with RCA Astrc-Electronics) for procurement of its DBS spacecraft. The remaining seven applicants have until December 1983 to take that step under their construction permits.

Because this abstract is due near the mid point of RARC-83, con- clusions based on the RARC outcome must wait until the IAC presentation of this paper. That presentation will focus on the probable future roles of full-power DBS systeme, proposed lower-power interim systems, and the possible effects of the RARC-83 conclusions on the implementation of the broadcasting-satellite service. - 66 -

IAF-83-72 TELE-X Per Zetterguist Swedish Space Cooperation

TELE-X is a multi-mission satellite in a telecommunications eystem, which will serve users in Sweden, Norway and Finland with data and video communications and direct TV broadcasting. The system will initially be set up for experiments and preoperational service, but it is designed with a view on a future operational satellite communi- cations system in the Nordic area.

The TELE-X satellite will operate in Ku band and is intended for small, low-cost data and video earth stations. To make this possible, the satellite uses high-power TWT:s (230 W) and a transmission system with frequency division multiple access and a single channel pec carrier concept (FDMA/SCPC).

The overall program, comprising both the satellite and the earth stations, is managed by the Swedish Space Corpor- ation. Nordic companies participate to a large extent in the industrial organization.

The satellite will be launched by Ariane in 1986. - 67 -

IAF-83-73 The Terrestrial Coverage of the Geostationary Satellite Beaji Bao Miaoqin, Zhou Xianven Institute of Spacecraft Systea Engineering,CAST ABSTRACT Thia paper gives a vector aethod to solve the geoaetric problea about the geostationary satellite beaa coverage* First,the relation between the antanna beaa and the coverage area is sought under the oondition of neglecting the attitude and orbit errors,then the beaa directional change induced by the errors is considered.Thus the required beaa can be solved for a given service area, with the actual errors being taken into aeount. The aethod given by this paper can be used in the beaa design of the power and disturbance budget of the satellite links.The difference between thie paper and soae present papers is the use of the vector aethod and the consideration of the attitude aad orbit errors. - 68 -

C.3 IAF-83-74 High Power equipment for TV-SAT/TDF-I Repeaters Volker LUCKBRT ANT Nach i icht entcchnik GmbH

Abstract -

The high power hardware is described for the repeaters of the Gentian/ French direct broadcast satellite TV--SAT/TDF-1.

The high power section of the TV-SAT/TDF-1 repeaters (.nmprises the following equipments:

FET driver amplifier TWTA 's High Power Isolator High Power Switch Output Multiplexer RF-Harness.

Based on the specific High Power features of the equipments ISIP i*>peatei lay-out and the resultung constraints for the bus concept will lip «leiiveil.

Futthermore, the relation is explained between the electrical, merhaim a! and thermal interfaces of the High Power Equipments to the satellite structure, thermal control and power conditioning. -69-

" ON BOARD AND GROUND EQUIPMENT FOR TV BROADCAST APPLICATIONS :

STATE OF THE ART AND EVOLUTION "

ABSTRACT - REF IAF 83-75

Equipments built by THOMSON and its subsidiaries In the field of TV direct broadcast by satellite, are described. Among these equipments are :

- Payload of the French TV satellite TDF 1, built by THOMSON-CSF within the framework of related franco-german cooperation, on behalf of Eurosatellite. Eurosateilite 1s a subsidiary of European companies, mainly, THOMSON-CSF and AEROSPATIALE for FRANCE, MBB and AEG- TELEFUNKEN for GERMANY.

- Main parts of the French up-link ground station, allowing to transmit TV programme from ground to the satellite. These equipments are deve- loped for the French broadcasting administration TDF, under the res- ponsabnity of TELSPACE. TELSPACE 1s a joint venture which major shareholder Is THOMSON-CSF.

- Consumer receiving equipments developed by THOMSON-BRANDT.

In conclusion, the main possible evolutions of the equipments described above are presented, allowing to meet the requirements of various systems of TV direct broadcast by satellite.

CO-AUTHORS: C. MICHAUD - THOMSON-CSF - Division Espace A. RABAOEUX - TELSPACE D. SAMSOEN - THOMSON-CSF - Division Espace J. SHEPHERD - THOMSON-BRANDT - 70 - IAF-83-76 TRANSMITTING ANTENNA FOR DIRECT BROADCASTING SATELLITES WITH RADIO FREQUENCY BEAM FINE POINTING CAPABILITY D. Fasoid* *Messerschmitt-Boe1kow-B1ohm GmbH, Space Division, Antenna Department, Ottobrunn; F.R.G.

INTRODUCTION In 1977 the World Administrative Radio Conference WARC settled regula- tions defining the coverage and the co- and cross-polar pattern of the transmit antenna of future direct broadcasting satellites in the 11/1? GHz band within the regions 1 and 3 i.e. Europe, Africa, Asia,Australia and CCCP. The conference results force severe requirements on the effi- ciency of the transmit antenna. In the joint Franco-German project TV-SAT/TDF1 two direct broadcasting satellites - TV-SAT for Germany and TDF1 for France - are going to be manufactured and qualified. The launch is scheduled for 1985. ANTENNA CONCEPT The paper presents the design objectives and measured results concerned with the TV-SAT transmit (Tx) antenna including the RF-sensor for beam fine pointing. The electrical requirements are based on the WARC regu- lations and additional pattern tolerance requirements of the customer. Fig. 1 shows the specified outer and inner radiation pattern envelopes which may not be exceeded by the actual antenna pattern. The required cross-polarization discrimination of s 33 dB is the most critical design aspect because of the highly elliptical beamwidth of 1.62x0.72 degr. specified for Germany. The basic electrical requirements for TV-SAT in- cluding the fine pointing capability via RF-sensor and APH (antenna pointing mechanism) are listed in Table I. 0 dB \ \ Frequency 11.; - t?.i mi 10 Polardatlon dniilar left h»nl '!*) EtBf 6S.« Ml - «S r 3.7; »5f. *l!irt

ir«to 9 Kand Trackin; Cipablllt> ? aits, oi*t!ioflonal •30 i 1 N • 0.3 *.r. morrat nncnoi' 1 \w ARC ii.roi nu / 1 circular ]»ri ftand ((HT9 -40 \ —3° -1° 2" Kwommct MouiCTWuts rot i»-s«i

1. Pattern Tolerance Mask foi TV-SAT Tx-i«n(enria. • 1.7 to 13.1 GHz. Major Beam AxK - 71 - A trade-off between applicable antenna typs,like offset Cassegrain an- tennas and multifeed antennas showed that under the constraints of the ARIANE launch fairing and the above given requirements a focus fed single feed offset reflector antenna is the optimum solution. The Tx-antenna is mounted on a carbon fibre re-inforced plastic (CFRP) tower with a night of 2.9 m and consists of an elliptical CFRP offset reflector with aperture dimensions of 2.7x1.4 mand an elliptical corru- gated feed horn. A fine pointing capability of the Tx beam is provided by means of an RF-sensor system that consists of an antenna pointing mechanism that properly tilts the reflector and a mode coupler. The mode coupler operates at 17.3 GHz and is integrated in the Tx feed sys- tem, whereas the tracking receiver is mounted in the communication module. The high cross-polarization discrimination of 2 33 dB of the Tx-antenna is obtained with an elliptical corrugated horn with vari ing corrugation depths along the horn circumference and an adapted hybrid mode launcher at the horn throat. For cancellation of the cross-polarization caused by different phase dependences in the principal planes of .the ellipti- cal corrugated horn, a phase-compensation section is connected to the feedhorn. This unit is foil owed by a septum polarizer and jnode coupler which detects the Ax, Ay and £ signals for fine tracking. The optimization of the antenna geometry like minimum reflector dimen- sions, focal length, offset angle etc. was performed by CAD techniques. As an example Fig. 2 shows the measured co- and cross-polar far field pattern of the Tx-antenna at the mid frequency of 11.9 GHz. Additional measurement results which had been obtained with a complete functional model of the Tx-antenna including the RF-sensor and tracking receiver will be presented. Emphasis will be drawn to degradation effects that occur for the antenna pattern, if the antenna beam is shifted by tilting the reflector via the APM and by thermoelastic deformation of the reflector. CONCLUSION The results obtained during the development phase of the TV-SAT Tx-an- tenna show, that a very compact and effective satel 1 ite antenna for direct broadcasting satellites with low cross-polarization i -33 dB) and side!obes (s -30 dB) and highly accurate RF-sensor fine pointing capability 0.06 degr.) can be designed by applying a focus fed offset reflector antenna with an elliptical corru- y^ \! ' MMAHTENKA! I • "j gated feedhorn element. Table I! summarizes some of the performance co*o»u«! data obtained with the TV-SAT ' """ Tx-antenna.

Reflector Oinensions 2.7 » « 1.4 . Foul Length 1.5 » BMt tfrHiystn) Ti i !« Beacon 3 I.J Cmlh. i -33 m 1st SUelokc Cain (Incl. w losses)!* Offset of tetcon SUtixi us-a t 0.15 *fr. Fig. 2: M»Mwem»nt remits ot TV-SAT T« antenna Title ii: owwcrnisric MT* OF TV-SH n-urniiu - 72 -

1AF 83-77

TITLE : ORBITAL DATA GATHERING SYSTEM : COMPARATIVE ANALYSIS BETWEEN MICROWAVE AND OPTICAL SOLUTIONS.

AUTHORS : H. ESCHAPASSE - L. FRECON - J.P. POULIQUEH - E. SEIN.

ORGANIZATION : CENTRE NATIONAL D'ETUDES SPATIALES J^ Avenue Edouard Belin

31055 TOULOUSE CEDEX

INTRODUCTION -

In the ninety's, one of the STAR system mission (STAR = BaTellite d'Application an Relais) have support high rate data links (about 400 Mbits/s) from earth orbit satellite to the ground through geosfa- tionnary relay satellites.

Two options are candidate to get intersatellite links : microwave {.A = 0.1 m) and optical (i= 0.8 mm) systems.

This communication purposes concern the comparative analyses between the two solutions from the point of view of antennas acquisition and tracking systems.

1<- GENERAL CHARACTERISTICS OF BOTH MICROWAVE AND OPTICAL TECHNOLlXUKS -

We shall present characteristic microwave and optical parameters of the T.A.S. (Tracking and Acquisition System) impressed by high data rale link budget requirements :

- antenna diameters - beamwidth - steering angles : . in a 240* angular cone for the Low Earth Orbit (L.E.O.) sei.elli (altitude orbit = 1 200 Km) •. in a 30* angular cone for the geostationnaiy relay satellite.

2.- TRACKING AND ACQUISITION SYSTEMS DESCRIPTION -

The main important features could be summerized In :

- acquisition and tracking mode - pointing precision in fine tracking - coarse and fine steering assembly - alignment assembly - acquisition time - beacon systems - weight and power budgets - gimballed systems. - 73 -

Then we point out critical technology issues needed by the lifetime of STAR systems (10 years) :

- microwave system . ntonopulse sensor . gimbal mechanism antenna . control loop . beacon

- optical system . pulsed semi conductor laser . line of sight steering and stabilization (scanning and rotating mirrors) . position detector.

3.- INFLUEHCE OP BOTH TECHNOLOGIES ON THE STAR SYSTEM -

It could be important to analyse advantages and drawbacks of each technology before choice. So, we must balance weight and power criterias (leading to the 4 : 1 weight advantage of lasers over milli- meter wave system) by tracking and acquisition subsystem's ones.

We point out the assessment parameters of T.A.S. feasability.

- system complexity.

- components and systems reliability.

Then, we consider the impact of integrating each alternative systems on the respective satellites.

- attitude stability problems caused by inertia of moving systems - stability requirements for performing specifications of high accurate pointing - constrains on attitude control - thermal requirements for equipments.

CONCLUSION -

The acquisition and tracking subsystems will take an important place in the technological choice for the STAR payload.

Accordingly, before choice, further studies must concerned gimballed mechanism and semi conductor lasers time life.

Re'fe'rence : Les satellites de localisation et de relais de donn6es STAR. "*~ 33e Congress of the International Astronautical Federation Sept. Oct. 1982 - PARIS - FRANCE. B. CUHBELIE - H. ESCHAPASSE - O.P. POOLIQUEN. IAF-83-79 Mexican National Satellite System Miguel E. Sanchez Ruiz Secretaria de Comunicaciones y Transportes Robert D. Briskman COMSAT General Corporation

The Government of Mexico is implementing a domestic satellite communications system to meet various telecomm- unications requirements over the next decade. The system is planned to provide a wide variety of services includ- ing television distribution, expanded telephony, improved data transmission and special ones catered to the require- ments of business and industry. Also, widespread distri- bution of educational television and rural telephony will be provided. The system is named "Morelos."

Mexico is currently using satellites extensively for domestic communications. Over two hundred earth stations are in operation using space segment leased from INTELSAT. This traffic will provide an excellent base when the Mexi- can satellites, described subsequently, go into operation during the middle of 1985 and will provide an initial fill- factor ensuring favorable economics.

The heart of the program are the satellites which are being built by Hughes Aircraft Company for launch by the space shuttle in April and September 1985. The satellites will be controlled from a master tracking, telemetry and command earth station located near Mexico City. The communications portion of the satellite provides a hybrid C and Ku frequency band capability. The satel- lite will be equipped with 12 narrowband (36 MHz) trans- ponders and six wideband (72 MHz) transponders at C band and four very wideband (108 MHz) transponders at Ku band. The narrowband C band transponders use 7 watt tube type transmitters with 14 for 12 redundancy; the wideband C band transponders use 11 watt tube type transmitters with 8 for 6 redundancy; the Ku band transponders use 20 watt transmitters with 6 for 4 redundancy. The previously described transmitters are fed to a combined C and K band antenna which provides high eirp throughout Mexico. In - 75 -

particular, the Ku frequency band eirp is greater than 44 dBH almost everywhere in Mexico which permits the dis- tribution of educational television via inexpensive earth stations having small diameter antennas. A planar array is used for Ku band reception. The satellite bus is spin stabilized with deployment of a telescoping solar cell drum and the erection of the C/Ku antenna done by ground command after the satellite has been placed in geosynchronous orbit. An attached McDonnell-Douglas PAM-D perigee stage is used to put the satellite in an elliptical transfer orbit following its ejection from the shuttle; the satellite is placed in the geosynchronous orbit by firing a STAR-30B Thiokol solid rocket motor (incorporated into the bus) near apogee of the elliptical transfer orbit. The satellite is 216 cm in diameter and 660 cm high after orbital deployment.

The satellite is designed for a 9-year life and incor- porates considerable redundancy. The satellite mass is 1240 kg in transfer orbit, 666 kg in geosynchronous orbit at beginning of life and 521 kg at end of life after expenditure of the hydrazine propellent used for station- keeping and attitude control. The solar panels supply 940 watts of DC power at beginning of life and 760.watts at the end of 10 years. During eclipse, 830 watts of power will be supplied by two nickel-cadmium batteries.

The domestic satellite program described will bring the benefits of high technology to the Mexican people and provide both improved and new communications services economically. - 76 -

IAF-83-83 COORDINATION AND MANAGEMENT OF THE INTELSAT TDMA SYSTEM B. A. PONTANO, R. J. COLBY

International Telecommunications Satellite Organization 490 L'Enfant Plaza, S.W., Washington, D.C. 20024

ABSTRACT

INTELSAT will introduce 120 Mbit/s Time Division Multiple Access (TDMA) into its communications network in the late 1983/early 1984 time frame. The system will initially operate with INTELSAT V satellites and later with satellite switched beams on the INTELSAT VI satellites.

A network within the INTELSAT TDMA/DSI system comprises four reference stations per satellite and a number of traffic terminals. The four reference stations operate in two pairs. Each pair provides network timing and controls the operation of the other reference stations and traffic terminals. Reference stations will include a TDMA System Monitor (TSM) which will be used to monitor system performance and diagnose system faults. The traffic terminals transmit and receive bursts in accordance with their traffic requirements. The operational focal point for the TDMA system is the INTELSAT Operations Center TDMA Facility (IOCTF). The interworking of the reference stations, the TSM and IOCTF to control, coordinate and manage the TDMA system is described in this paper. The IOC controls, coordinates and maintains the TDMA/DSI networks by the use of data, voice and TTY links to the reference stations. Using the data links the IOC can access the majority of the mimic displays available to the reference station operator perform remote system start-up and initiate and cancel burst tine plan rearrangements. The leased voice circuits enable the IOCTF to access the Engineering Service Circuits (ESC) order wire system in each network using the reference stations as "gateway terminals". A BTP for the INTELSAT TDMA system will contain all the operational parameters for the terminals in the network.

To ensure that critical elements of the BTP have been correctly loaded into the terminals, they are grouped into a special format and transmitted front the IOC using the CCITT X.25 data protocol for error protection. When successfully received, the data is translated and stored in -77 -

the background memory which will subsequently be used to control the terminal when the new time plan is envoked. To obviate loss of traffic when new time plans are envoked the INTELSAT TDMA/DSI system provides a fully synchronous Burst Time Plan rearrangements capability. This involves changing the position and/or length of some or all bursts within the frame of any TDMA transponder. The reference stations and IOCTF facility are capable of initiating and cancelling Burst Time Plan rearrangements.

To assist in the maintenance of INTELSAT'S quality of service criteria, all TDMA terminals are capable of exchanging alarms. The alarms are selectively addressed to the terminal originating the burst. The use of these alarms to diagnose system problems is described in the paper. The reference stations log all alarm conditions and can assist traffic terminal operators in diagnosing faults. Since the reference station displays are available to the IOCTF it also logs the alarm incident and assists in fault location, especially when a larger scale network problem exists.

The paper conclud-es by giving a number of examples of management and coordination procedures including: o System start-up o Burst Time Plan generation and distribution o Burst Time Plan change procedures o System monitoring and failure diagnostics o System line-ups. IAP-83-84 RESULTS OP THE DEVELOPMENT OP MULT1PLEACCE3S EQUIPMENT FOR THE SATELLITE COMMUNICATION SYSTEMS IN THE USSR V.M, Dorofeer, V.M. Teirlin Intercoemos Council, USSR Academy of Science* The paper presents the main results of theoretical and experimental studies performed within the scope of work on the development of multiple-access equipment utilized in the USSR satellite communication links* The major technical characteristics of frequency and time division multiple access equipment are given* The results of experimental studies and operation of TDMA equipment at 40 Mbit/a and FDltt equipment uaing the "Single Channel per Carrier", Delta-modulation and "Multi-channel Digital Stream per Carrier" methods are reported. lAf -83-85 " '?** " ABSTRAC1 1HE PROGRAM MANAGEMENT OF THE TELESAT SPACE SEGMENT (A Program Manager's Recollections) by J. S. Korda Manager, Spacecraft Programs Group Telesat Canada

Telesat Canada came to being on September 1, T969. The Canadian Parliament stated our mandate as: "...to establish satellite telecommunication systems providing, on a commercial basis, telecommunication services between locations 1n Canada.* Telesat Canada Act In fulfilling this requirement we started commercial operation on January 1, 1973, and thus became the world's first domestic satellite communications system. The "Telesat Story" has been explained and extolled many times over the years; how we grew In employment from less than 25 to a staff of 500; how our capital assets expanded from $74 million (CAN) In 1972 to $380 million (CAN) In 1982; how our earth station network consisting of over 120 Installations covers every region of Canada including the Arctic as far north as 80" with Took angles of less than 1". The backbone of our operation and our success has been our satellite network. The first launch took place on November 9, 1972, and since then we have launched six more satellites, and two more spacecraft are 1n storage awaiting launch In 1984. Our satellites grew 1n size and complexity from 560 kg Transfer Orbit Weight and 12 RF channels to 1217 kg and 24 RF channels. They operate In the 6/4 and 14/12 GHz bands. They encompass spinners and body stabilized designs. While the beginning was extremely simple: start working!, the Telesat Canada Act has spelled out a challenge as well: be commercially viable! To strive for technical excellence and be a money-maker at the same time 1s an Inherent contradiction to all engineers. Thus the program manager starts with several handicaps both Inside and outside his organization. Essentially he must reconcile the roles of Genghis Khan and a father confessor. The performance specifications of our first spacecraft contract were relatively simple, but endless hours were spent on the "management* aspects. To a large extent our original managerial philosophies are still In evidence. For example, contracting for "performance" Instead of "design" was one of the more significant decisions which still - 80 - Influences our procurement process. While supplying "performance" Instead of "design" opens up competition and Innovation, It does require a different approach for "verification". Thus careful «nd. In most cases, arduous negotiations are In order before awarding a contract. In 1970 we Introduced the concept of a Test Matrix which, we believe, was a novel approach at that time. We also Introduced a very elaborate testing sequence for the transponder subsystems as WPII as for the fully assembled spacecraft. These tests are not only extensive but carry heavy penalty testings for failures. We believe, and the subsequent results have verified that we are rtqht In our approach. Besides performance and verification the third part of our technical "triumvirate", ihe product assurance requirements, Including design reviews, parts procurements and burn-1n criteria, quality Inspections and reports, gives us reasonable assurance that the final product Is not only technically sound, but capable of attaining the Intended lifetime. So far we have discussed the easier part of any program; deciding between technical "Imperatives" and "niceties". Now, we have to agree on the price. Since our contracts are always fixed price with 1n-orb1t Incentives, and since we are a small company without outside financial affiliations, we drive a hard bargain. The program manager not only has to make recommendations for fair price assessment, but also recommend deletions In order to arrive at a reasonable budget consistent with providing an acceptable product. Within five years of the first launch we were In our greatest expansion program concurrently contracting for five advanced spacecraft having two different payloads to be supplied by two prime contractors. As an added challenge It was planned tc launch all five spacecraft within a two year period; the first two on three months centres, one on a Delta and one on the first commercial Shuttle flight! Oespite all the careful preparation 1n arriving at a mutually satisfactory contract., throughout Its execution conditions, assumptions and requirements do change. A Contract cannot be looked upon as being the "eleventh" commandment! To be responsive to and responsible for this dynamic situation, we, as customer and program management, have to be Intimately Involved In all phases and yet we must keep In mind the "performance" oriented, fixed price nature of our contracts. What does the future hold? As somebody said: predictions are difficult— especially 1f they Involve the future. On a very personal note, It Is my belief that our company and all similar sized domestic and/or regional commercial satellite communications carriers will opt for small, relatively simple designs Instead of large platforms. This 1s believed to be true not only because of financial but also because of national political considerations. TAF-83-86

COMMERCIAL COMMUNICATIONS SATELLITE MARKET AND TECHNOLOGY IN THE 90'S

Dr. R.T. Filep Communications 21 Corporation Redondo Beach, California

ABSTRACT The commercial communication satellite market has experienced a phenomenal growth during the past five years and is scheduled to grow at an equal or greater rate through 1995. Current and planned expenditures are provided in relation to ITU regions, as well as an assessment of the worldwide market in relation to communication satellite frequencys and services. Attention is also given to generic launch vehicle requirements.

Commercial communication missions in this time period may require ceTtain technological capabilities that could be tested via a low earth orbit space station. The results of a user requirement study conducted with common carrier, spacecraft manufacturers, and research personnel to identify such technologies is reported. Antennae, structures, and propagation needs are discussed. - 82 -

IAP-03-Ba INCREASING THE SHIFBOBHB TELEMETHIC SYSTEMS CAPACITY WITH THE CHANNEL FREQUENCY DIVISION

Blas;hevitch,B,I,t Kushnereveky J.V., Modla R.N., Pogribnoy V.A, Intercosmea Council, USSR Academy of Sciences The systems mentioned in the title are widely uaed for researching tho upper atmosphere and the outer apace du- ring parallel transmission of high-speed signals from se- veral transducers (not more than 20) • Exacting demands are placed upon their capacity to ensure an adequate ac- curacy of the system as a whole since the quality of the channels is limited* The capacity of the given telemetric systems ia deter- mined by the speed of responce of the subcarrier frequency oscillator (SPO), as well aa by their possibility of pre- processing the input data* Considered are construction principles of high—precision SPO. the speed of responce of which does noii exceed one cycle of the basic osciJla- tions and which simultaneously provide the signal prepro- cessing. The eaaence of thia processing lies in transfor- ming lit(UΑ ratio or U/^C/Ji product of the two signals in- atant values into the ratio frequency deviation, as well aa in transforming the j/3 C/^/lSy instant signal value* into the ratio frequency according to the relationship

where 4?- the scale coefficient. High speed oT reeponce and the etability of the trans- mitting characteristic is achieved through the use of two-point integrator. The above mentioned possibility of the signal preproceasing is ensured by the use of one of the signal being processed as a reference signal, The mentioned principles are realized in the SFO» co- vered by the PRD3-2 multi-channel telemetric aystema/the Processing and Recording Data Syatema/and F3U -I the Frequency Subcarrier Unit/, - 8? -

IAF - 83 - 92 The Active Microwave Instrument (AMI) for ERS-1 B. TheiLe, G. Dieterle, W.I. McMillan The Active Microwave Instrument (AMI) shall be flown aboard the first ESA remote sensing satellite ERS-1. The AMI is a 5.3 GHz radar and performs three distinct measurement functions: Imaging, Observation of ocean waves and wind measurements over ocean. Imaging and wave observation employ the synthetic aperture radar (SAR) technique. The wind measurement is based on the determination of the ocean surface radar reflectivity (scatterometer) which in turn is related to the wind speed. The AMI uses the same radar electronics for SAR and scatterometer functions. The antennas are different. The SAR uses a 10'1m planar wave- guide array. The scatterometer has a set of three planar antennas. SAR and scatterometer functions have their de- dicated on board preprocessors. In-flight calibration can be done by means of an onboard calibration unit. The in- strument's mass exceeds 300 kg. Power consumption in imaging mode is slightly above 1kW, the imaging data rate is about 100 M bit per second. An extensive ground pro- cessing is required to generate the final products. - w - IAF - 83 - 93

INCREASE OP THE SEPARATING CAPACITY OF PASSIVE RADIOMETRIC! SYSTEMS

THROUGH JOINT PROCESSING OP VISIBLE RANSB DATA

D. Mishev - Central Laboratory for Space Research at the lhilgnrian Academy of Sciences

Various passive radiometric systems for measurements of natural Irradiation of natural formations are applied in the remote sensing of the Parth.The application of these systems is United to a cexteJ- dogree by the relatively large aperture of the antenna system and in consequence low separating capacity is obtained along the jwrface of the studied natural formation* This paper examinee the possibility for eignifleant improvement of the separating capacity ef passive radiometric systems through tfr joint processing of the data with those- from the multicliBgn#l vi- spectrometrlc systems*

Some results are given as obtained with the application of tfa* • oxamined method,including implimentatione id thin the project Bulgaria'1300-11, IAF-83-94 RESEARCH AND DEVELOPMENT OF SYNTHETIC APERTURE RADAR Y.Itoh Y.Hisada National Space Development Acjency of Japan ABSTRACT A synthetic aperture radar (SAR), one of the promising micro- wave sensors for earth observation, is being researched and developed by National Space Development Agency of Japan (NASUA). The preliminaly study was started in 1979, and the research on critical technologies is now carried on. It is planned that SAR will be equipped as a payjoad for the earth observation satellite in near future such as Earth Resource Satellite - 1 (ERS-1) of Japan. And the fundamental policy in the research and development of SAR is to make the system design simple for the test operation and to get the better image data than those of SEASAT SAR. Under above requirements, the specifications of the SAR system during the research and development phase were determined as follows; Frequency L-band Polarization H-H linear Orbit 570 km sun-synchronous Off-nadir angle 33° Swath width 75 km Resolution 25 m x 25 m Multi-look number 4 (azimuth) Signal-to-noise ratio 7 dB Signal-to-ambiguity ratio 20 dB. In order to realize the system which satisfies these specifi- cations, we started the research and development on the following critical technologies. 1) to keep the antenna panels flat in the space environment 2) to obtain high power by a solid-state amplifier 3) to get a high time-bandwidth-product (TBP) device for the pulse extension 4) to achieve high frequency stability with a crystal oscillator The antenna is one of the components that we are making an effort in the research and development now. The antenna of SAR consists of micro-strip array of 1,024 elements and its dimensions are 2.1 m x 12 m. Due to the constraints of 2.2 m diameter of H-I launch vehicle's payload section, the antenna must be deployable. A solar paddle deployment mechanism is applied to the antenna expansion. The deployment sequence consists of three stages as shown in Fig.l. In the first stage, the antenna package is released to the right angle to the sidewall of a spacecraft. In the second stage, each half of the antenna deploys to the opposite side of the center arm simultaneously. In the third a*si, », the deployed antenna tilts to the off-nadir angle. Tn eaci: .age, spring-work - 86 -

latch-up mechaniam is employed for locking. Some trial products, hinqes and partial model of antenna pan«?| , have already tested. The acquired data from these tests such as latch-up accuracy of the hinges, thermal sttain of the panel m\A the radiation characteristics of the micro-strip array antenna ware very well as we planned. Reflecting upon these results and experiences, the full-scalp bread board model with dummy panels was made arH tested to be tjreai success. A thermal model of the antenna pane] will be manufactured and tested by March 1984. We are also making an effort in developing some of the elect Ti<~ai components. Critical components such as a chirp modulator with a surface acoustic wave (SAW) dispersive delay line (DDL), the so]id state high power amplifier including exclusive power supply, the stable crystal oscillator and a part of control unit were produced by way of trial. Tests of these components were carried out without serious trouble. Major results of these research are 400 - 700 of TBE by .'*AW DPI,, 600 watts of output power by a single amplifier and 10 ' of frequency stability in short time scale by an oven-controlled c-ryslaJ oscillator. The bread board model of the electrical portion wilt be eompl*»•<».? by March 1985. The preliminaly design review will be held by 1985 through Mi«»«.«« trial products, tests and analyses.

90*

let stage 2nd' stage

Spacecraft

SAR Antenna (KFRP,N0MEX, CFRP,Almi,CFRP) Center Arm {CFRP)

3rd stage

Fig.l The deployment sequence of SAR antenna. - a? -

IAF-83-95 MICKOWAVB RADIOMETRIC INVESTIGATION OP CLOUD CHAPJlCTfiRISTICS PttOM THE SATELLITES L.M, Mltnik Intercoamos Counoil, USSR Academy of Sciences Information en tho cJoud cover parameters ia essential in investigations of atmospheric procasosi of the different scaler*, in studies nf the ocean urn) atmosphere interaction, :1 n moilelling cf antropoi.;enic effoofc on climate as well as in solution of other practical and theoretical problems, A body of data on oloudineaa eharaoteristics are increased aignificaiitly due to meaauremants from tha satellites. Micro- wave radiometric acnalng data became valuable source of in- formation on cloudiness. It was caused by lenacr values of the attenuation of omission at the •'itmonphsre in comparison with IR ran^a, distinct apect.ral relationships of thia attenuation with liquid water content, tomporature and phase state of olou'ls, precipitation characteristics and in— tc/rrafcod water vapor contoi.it of the atmosphere. Outgoing radiothermal radiation spectra of the ocean-clo- udy atraoaphere system obtained in numerical and real experi- ments permit to estimate ths variations of the brightness temperature T^ resulted from cloud parametria chances and servo as the oasis for development of solution methods of the inverse problems. This variations are maximal over the frequency ranges V~ cf 30-50, <~75-110 and'~Ii:5-I7o GHz. At ^ 2*75-110 GHz there

are considerable Tb increases evon though value of integrated cloud liquid water Q is small* The brightness temperature contrast of cloudy region against the oloudless background constitutes ^10-18 K at V ^25-50 GHz and~'2'3-45 K at V^75- 110 GHz when Q = 0,2-0»3fec/ni' an d oloud temperaturo is In the range from -10 to +10 C (it is typical values for Cu and As cicada). Because of integrated oloud liquid water of a major part of the Earth1s cloud cover ie not exceed 0,1- 0,2 kg/m it is oxtrnmely advisable to us* a epeotral region close to 90-100 GHz for sensing of the atmospheric parame- ter a. Along with the cloudiness parameters multichannel mio» rowave radiometric measurements make possible to estimate integrated water vapor of the atmosphere, the ocean eurfaoe temperature and state, that is L-nportant to study cloud dy- namics, heat and moisture exchange between the ocean and the atmosphere. Specific difficulties in interpretation of satellite mea- surements of cloudiness characteristics occur through avera- ging of the microwave emission within the boundaries of re- solution element and beyond them with weight which in deter- mined by antenna pattern of radiometer. To estimate T, field spatial structure restoration errors occuring due to averaging it is used data of clouds microwave emission measurements from the R/V Academician Alexander Nβ- smeyanov in the Atlantic, Indian and Pacific oceans in sunnier

1982, The smoothing of highfrequenoy components of Tb field spatial variations spectrum are well appeared in the compari- son of the results of microwave vessel obsorvatlone with date, of satellites which have different resolution element else*. - 80 -

IAF-83-96 HYDHOrHYSICAL ANALYSIS OP REMOTE OCEAN MEASUREMENTS PROM SPACE O.K. Korolaev, V.K. Kosnyrev, V»N, Kudryavtaov, V.S» Suetin Marine Hydrophyaical Institute, Ukrainian SSR Academy of Sciences, Sevastopol, USSR Over two years tho USSR has successively conducted experiments with the oceanographic satellites "K0SM03- 1076"» "K0SM03-I15T", "JNTERC0SM0S-2I". Remote measure- ments were carried out in optical, infrared and microwa- ve spectra of electromagnetic radiation. The apparatus for remote sensing involved a spectrophotometer of visib- le band, infrared radiometer, microwave polarimeter and microwave spectrometer. After being appropriately correc- ted the data from remote measurements were translated .in- to physical characteristics of the ocean and presented aa corresponding charts. Of particular interest were calculations of ocean sur- face temperature which were performed using data from microwave measurements. The constructed charts show all the basic large-scale features of temperature field in the North Atlantic, The most pronounced of them is a zone of higher temperature gradients, associated witli frontal zones of the Gulf Stream and the North Atlantic Current. Axe3 of these currents vary with time, wifch existing bo Mi seasonal oscillations of the current axis position and wave-like oscillations-meanders* To construct each chart measurements from 5-7 satellite trajectories over 3-5 days were used. Maximum deviations of the current axis from .its mean climatic position reached 350 km* Based on average monthly charts of ocean surface tempe- rature , as averaged by 5 trapezia, the dynamics of tempe- rature anomalies in the North Atlantic was followed. The temperature anomalies were obtained by subtracting climatic values from average monthly ones and were described by 5 gradations within -3+5 C* A simple advective model based on the linearized equation of heat conduction was employed in order to.calculate transformations of temperature ano- malies. The calculation* involved data on velocities of surface currents in the North Atlantic estimated by the diagnostic method. The calculation procedure consisted in predicting the position and intensity cf anomalies one month ahead comparing them with satellite data. The ana- lysis has shown that the position of predicted anomalies is rather well described, the r,m.e. error in temperature prediction being 1-1,5 C* The use of remote sensing data with application of hyd- rodynoriic models will make it possible to gain an insight into the ocean depths* The dependence cf dispersion r«ia- tion for internal waves on the vertical diaLribuiion of Brunt-VSiatflS frequency forma the foundation for one of auch methods, Aβ shown by calculations, it ia possible to determine bedding and thickness of the aoasonal fchermo- cline and density drop in it, na well as parameters of the main thermocline from the given dispersion relation. Another method, which uses measurements of horizontal temperature gradients and siopes of the level as its ba- sis, enables calculation of water temperature and current velocity, in fact, at all ocean depths rather hjRh accu- racy. - 90 -

IAF-83-97 Determination of Ocean Reflectance by Hultlspectral Reaote Sensing B. Piesik, G. Zimmerma'.nn • Institute for Space Research, Academy of Sciences of GDR, Berlin .

Summary . . The reflectance of the atmosphere-ground system is measured by a multichannel spectrometer MKS on board-the satellite "Intercoamos 21" in 13 narrow spectral channels between 400 and 900 nm /1/. The aim of this experiment is the in- vestigation of ocean reflectance and its dependence on wavelength A and on suspended material (phytoplankton). To get thi.s information from the radiance measurements the datas has to be corrected for the influence of the atmo- sphere and surface reflection.- This can be done by i sing the measurements in some of the channels:

The measurements in the absorption channels of the 02-A- band near 760 nm and in the. nearby atmospheric window 75B nm are used according to a method, proposed by Badaev and Halkevich /?/. As the result one gets a splitting of the radiance-in the window at 758 nm into the "path ra- diance". Lp and into a ground contribution and also the optical thickness T.. at 758 nm can be determined. By usins the strong correlation of optical, thickness at different wavelength (corresponding to Tawartkiladse /3/)- as well as between r.ptical- thickness and -"normalized" path radiance (corresponding to Badaev et al /4/) the path radiance f.p and opt ical thickneb-s t for every other channel can be calculated. With these parameters Lp(^) , v(A) the ra- diance leaving the water surface at h is easy to com- pute. - 91 -

Because we do not know-wether the correlal.i <>n ''Hindi s«/i •nrca".. are representative alsn for other oecnn regions*. i-«; nxamln ed some alternatives to this procPRHlrw? concept: Instead of using, the riatan in /}/ we nsp I ho wnvelou/'.ih 7'> and 794 (and at "clear water oomllfcicmn" alr.<> f>7fi) Tm- Uie determination of 9t in the often nn«d rrlallnn for the aeroaol optioal thiekneaa: .

ae • ae

Instead of using the datan In /'l/ we use resulLn of n calculations as e.q. Gordon eh ai /S/ tocompute the radiance. In the paper more details are reported about the algorithms and some results of "corrected ocean refleot.-im-s" are fshown and discussed.

Literature

/1/ K. Bisohoff et al Acta ., Vol. 10, No. 1 p. 11. 1'Wl /?/ Badaev, W.tf. ; Malkevich, M.S. Fiz. Atmosf. 1 Okeana 1'i. No. 10, p. 10??, tQ7« (in russian)' /3/ Tawartkiladse, K.A. Fiz. Atmosf. i Olreana 1?, No. r>. p. 1'if,, 1076 (in russian) /k/ Badaev, W.W.J Koslov, G.M., Tnch^rninnlniw, W.N. Fiz. Atmosf. i OlfPana 17. Tin. 5, p. Vt?. 1'i«1 (in rus.siarO /5/ Gordon, H.R. Appl. Opt.. Vol. 17, Wo. 10. p. - 92 - 1AP-83-I0I THB ATMOSPHERIC IMPACT ON THE SPECTRA AND IMAGES OP NATU- RAL FORMATIONS AS OBSERVED PROM SPACB Kondratyev K.Ta., Koeoderov V.V., Smokti O.I* The USSR Academy of Sciences Obtaining and interpreting the pictures and spectra of the Berth's surface are one or the most important direc- tions of the present-day space studies* The efficient use of such information depends on correct consideration of the distorting effect of the atmosphere in machine proces- sing and analysis of the spectrophotometry information obtained from space* The methodical basis for such consi- deration in the visible spectral region (0,4-0.8 urn) is the conception of the transfer function for the atmosphere- surface system 1-3 • Software means involved in machine processing of the information should be realised, in a way to provide real time filtration of the useful signal about a natural formation under investigation against atmosphe- ric interferences* The corresponding algorithms and techniques are dis- cussed necessary for atmospheric correction of images and spectra of natural formations in the 0*4-1*5 urn wavelength region* Practical problems are considered In detail, connected with application of analytical solutions and spherical harmonics techniques to numerical processing and atmosphe- ric correction of multispectral Images from space and the data of the scanning systems. The effect is studied of an elongated atmospheric phase function and its vertical va- riations as well as of non-Lambertian reflection from a surface on the spectral* spatial and angular changes of the transfer function* The efficiency of the proposed al- gorithms techniques and schemes for atmospheric correcti- on is illustrated on the basis of the analysis of the Barth*s surface Images obtained from the satellite system "Meteor"• - 93 -

IAF-83-102 METHODS OF DETERMINING OPTICAL ATMOSPHERIC PARAMETERS BASED ON SPACE-IMAGERY EARTH-SURFACE DATA

Agapov A.V., Usikov D.A., Fomenkova M.N. USSR Academy of Sciences, Moscow Space Research Institute Remote sensing results showed that the distorting effect of the atmosphere consists in that an earth-sur- face space-image differs from an appropriate near-earth image by distortion in color transmission and by chang- es in spatial contrasts. It is difficult to reduct a space image to a near- earth one due to lack of efficient methods for simulta- neous measurements of atmospheric parameters.

Two methods are considered in this report. The first method is based on the fact that one and the same surface region photoed different spectral bands has different spatial contrasts and, therefore, the change in these contrasts carries the information about optical properties of the atmosphere.

For the second method it is essential to use the track multispectral information obtained in absolute units of brightness. Such data together with albedos known for certain surface regions allow optical atmos- pheric properties to be determined using the changes in brightness of reference objects,

These methods were experimentally tested in the joint Soviet-Bulgarian experiment "BUlgaria-1300-2". - 94 -

IAJ?-bJ-T03 RESULTS OP SPACE EXPERIMENT ON OCEAN STUDY G.K, iCorotaev, V,S. Suetin, Yu.V. Terekhin Marine Hydrophyaical Institute, Ukrainian S.S»R. Academy of Sciences, Sevastopol, U.S.S«R. Construction of apace ayatom for remote sensing from satellites is one of the moat important problems for 'le- va "loping methods of ocean obaei'vations. Experiment with special satellites "Kosmos-1076"» "Kosmos-1151" was the firat atage in solving this problem. Methodical problems of remote measurements of oceanic parameters as well as masa automated processing of observational results were solved during the experiment. Determination of basic fea- ture of the ocean - field of surface temperature preci- sely enough to solve the problems of oceanology, is se- rious problem. An estimate of possibility of remote measurements o£ disturbance parameters, optical characteristics of water, boundaries of ice cover, atmospheric parameters is also of a great interest. Set of scientific instruments for experimental arti- ficial satellites contained multichannel radiometers of VHP and thermal IR band, spectrofotometer of visible and near IR band. Software for mass processing ef infer- mation using computer was created in the course of expe- riment. The system was used to process and interpret the data of measurements obtained during more than a year and a half. The proceaaing included the creation of ope- rational mass of intensities of radiation of the "ocoan- -atmosphere" system, plotting charts of the most impor- tant parameters of the ocean, an estimate of accuracy in results trustworthiness* Ocean surface temperature is determined with an accuracy of 1.5 , wind speed in near water layers - with an accuracy of 2 m/s. The method for calculating the depth of surface turbulent layer in the ocean based on the data of successive measurements of surface temperature field were worked out. Variability of the Gulf Stream frontal zone position was analysed. Hydro- physical parameters were calculated using the algorithms based on the models of connection between values of radi- ation measured from the satellite and parameters of the ocean and atmosphere* The data obtained was analysed as a whole statistically to correct calibration of radiome- ters and specify some model characteristics* Simultaneous measurements of radiation in the set of channels were used for single determination of hydrophyaical parameters. Measurements at a wavelength ef 3*2 cm in two pelariaa- tj ona at an angle of 60 to the vertical in the TOP band contained the moet quantity of information from standpoint of calculation of the ocean temperature. Tracer way of ra- diation measurements did not allow ue to obtain detained features of temperature, wind* clc)u

IAF-83-104 DYNAMICAL INTERACTION OF THE SENSIBLE HEAT RELEASED BY SEA SURFACE TO THE OUTBURST OF THE COLD AIR Lai-chen Chien Institute of Physics, Academia Sinica, Taipei, Taiwan 115, China

A1r-sea Interaction during the period of the outburst of the cold air plays an Important role in a wide range of weather, climate and ocean problems. It has become significant problem to treat the effect of the sensible heat released by sea surface 1n relation with the large-scale atmospehric motion. In winter, the high pressure center originating over North China and Siberia. During the period of the outburst of the cold air, the polar continent air mass diverged outward from its center counterciockwisely and crossed the isobaric lines. Entering the East China sea, the dry polar con- tinent air mass absorpted heat and vapour, and was modified as maritime air mass. The sea surface temperature has been recognized as an significant factor to estimate the amount of the sensible heat transported to the atmosphere and 1s an Important input for the numerical weather prediction. In this study, the sea surface temperature Is determined from the radiance detected by the Advanced Very High Resolution Radiometer on the TIROS-N/NOAA satellites. As 1s well known, the problem in obtaining the sea surface temperature deals with cloud filtering and water vapour correction. In the absence of cloud and water vapour absorption, the brightness temperature observed with a space-borne window radiometer Is equal to the sea surface temperature. Various multiple spectral window methods are used to detect cloud-free radiance. And then water vapour absorption Is corrected. The cloud parameters can be inferred along with the sea surface temperature. In numerical experiment, a four-level primitive equation model in pressure coordinate is used to investigate the atmospheric motion over the East Asia during the period of the outburst of the cold sir. And the twenty-four hour forecast 1s performed for the case of interested. The results show that the sensible heat released by sea surface plays an Important role in atmospheric motion during the period of experiment. IAF-83-105 REMOTE SENSING OF PRECIPITABLE WATER BY A THERMAL INFRARED MtfLTICHANNEL APPROACH C.IJlivieri Dipartimento-Aerospaziale,Universita di Roma,Italy

Water vapor in the atmosphere is an importrant constituent because it plays a significant role in the absorption and emission of radiative energy.Measurements of this constituent, aside from being an aid in the understanding and prediction of weather and climate, allow to improve the accuracy of the remotely sensed surface temperature when water va- por window spectral regions are used; in fact it is necessary U> apply a correction for atmospheric water vapor absorption which canses an un- derestimation of the actual temperature. Satellite sensing of the pre- cipitable water in the atmosphere has been accomplished in the micro- wave and thermal regions of the electromagnetic spectrum. Since the bulk of the water vapor is contained in the lowest layers of the tro- posphere, transparent regions have been used to seek information about that. Previous studies showed that a precipitable water assesment can be obtained over the oceans on a large spatial and temporal scale with a satisfactory accuracy either from passive thermal infrared or micro- wave radiometric data whereas the total water vapor content over land masses can not be inferred satisfactorely (in both spectral regions), because of the large temporal and spatial variability of the physical state of the surface. The algorithm here proposed to infer the atmos- pheric precipitable water uses measurements in three channels, cente- red at 10.8, 11.9 and 12.7 micron(hereinafter called channel 1,2,3 re- spectively) . In order to combine the equations derived from the radia- tive transfer theory applied to each channel, all the radiances were reduced to the same wavelength (ch. 1 as reference) and the atmospheric contributions were correlated ,being not independent .A simple ratio of differences in radiometric measurements was found to be linearly de- creasing with atmospheric precipitable water, developping a radiative computation scheme which can simulate the spectral radiances at satel- lite with a resolution of 0.1 cm" in the water absorption region of in- terest. This simulation program synthetized spectral data for several different mean atmospheric conditions over the Italian seas. The neces- sary measurements to validate the algorithm were obtained by AVHRR/2 of the NOAA-7 satellite for the channels 1 and 2 whereas. ch3 was simu- lated on the base of the spectral response filter of a channel of the Goes/5 satellite.The prec$itable water so inferred on a small spatial and temporal scale differ by no more than 0.35 g/cm from independent water vapor data obtained by radiosounding. - 98 -

N° 9146 IAP-83-106 F- 1O-22'2

ACTIVE MEASURES. FOR REDUCING THE GLOBAL CLIMATIC IMPACTS OF ESCALATING CO- CONCENTRATIONS

by

S. S. Penner, A. M. Schneider, and E. M. Kennedy

Energy Center and Department of Applied Mechanics and Engineering Sciences University of California, San Diego La Jolla, California 92093

Abstract

The global buildup of CO2 produced by fossil-fuel burning and possi- ble associated long-term climatic changes have become the subject of in- tensive investigations and discussions. Although the time scale on which significant climatic changes (e.g., mean temperature changes of several degrees, appreciable changes In global and regional rainfalls and winds, etc.) are expected to occur is long, it has been noted by many observers that the magnitude of the energy system is so vast that remedial changes in the primary resource mix should preferably be initiated within a decade or sooner.-

The notion that the most economical energy source will be replaced globally in response to long-term climate model predictions may well turn out to be untenable. However, before policy matters of this type can be discussed reasonably, it is apparent that careful assessments must be made of alternative global measures that do not require curtailments of fossil- fuel applications.

This study on active measures for reducing climate changes caused by escalating CO2 concentrations deals with potentially important areas of research. It is not a recommendation for implementation of a program.

We find that reductions in the solar input to the earth by reflect- ing sunlight directly are prohibitively costly. On the other hand, de- sired changes in earth albedo through judicious Introduction of small particles can probably be accomplished at very low or negative costs through the appropriate use or alteration of combustors on high-flying aircraft. - 99 -

IAF-83-107 Advanced Visible and Near-Infrared Radiometer for Earth Observation

Syunji Takamura and Tsunehiko Araki of NASDA Ryushi Kuwano, Riichi Nagura, Yoshito Narimatsu and Tetsuya Satoh of NEC

At present, the National Space Development Agency of Japan (NASDA) is developing a Visible and Near-Infrared Radiometer (VNR) to be mounted on the earth observation satellite. This paper reports an outline of the VNR. The VNR images earth's surface by separating the reflected light on the earth's surface into four bands from visible to near-infrared in wavelength. The light reflected from the earth's surface is applied through two dioptric telescopes into the VNR. Then,each incident light is divide3 into two bands through a prism and filters of the telescope and focused on CCDs (Charge Coupled Devices). Since the VNR uses CCDs, a ground resolution of 25m (corresponding to one CCD element) and a swath width of 150km on the ground are achievable by electronic acanning using the movement of the satellite. In order to achieve these capabilities, three CCDs (about 6000 elements)/band are arranged on the focal plane of the optics of the VNR through half-prisms so as to be equivalently continuous. The CCDs output analog image signal from each band is converted to a digital signal of 8 bits by a signal processing circuit, and transmited as the processed signal to the transmitter of the satellite.

In order to achieve this wide swath width with the limited weight and dimensions, the optics should provide a wide field of view. Through examination from various angles, it has been* determined to adopt aspherical dioptric teles- copes for obtaining high-resolution performance while maintaining a wide field of view. At present, a high- accuracy aspherical lens manufacturing technique is also being developed while enhancing the development of the VNR in the initial phase.

As discussed above, a lightweight, high-performance, high-reliability and low-power consumption VNR system can be constructed by adopting electronic scanning using CCDs and aspherical dioptric telescopes. The development technique of this VNR system, will facilitate expansion of the swath width, improvement in resolution, and development for the stereo and mid-infrared radiometers. The authors will accomplish the trial manufacture and testing of the VNR system and check its optical and electrical performance charactefistics. - 99/a -

IAF-83-109

THE SPOT-HHV HSTBUMENT AN OVERVIEW OF DESIGN AND PERFORMANCE

J.P. MIDAN CENTRE NATIONAL D» ETUDES SPATIALES Toulouse - France

The HRV /High Visible Resolution/ is an Earth Besource Sensor built by MATRA for CNE3 for the SPOT Series of spacecraft* The SPOT spacecraft will be placed into orbit early in 1985*

After a brief review of the basic SPOT mission features# this paper deals with* 1* Detailed description of HEY performance requirements, system and main sub-system design, and technologies involved* 2. Typical problem areas Involving extensive design trade-off analysis and testing* Two detailed examples are used as illustrations ii - mechanical design and thermal distortion analysis and results - signal-to-noise analysis and calibration considerations. Keywords - High Resolution Visible, SPOT Earth Remote Sensor* Charge coupled Device, Off-Nadir Viewing, on-board computer* - 100 -

IAF-83-110

DESIGN AND DEVELOPMENT OF AN OPTICAL SCANNING MECHANISM (OSMA) WITH MINIMUM MOMENTUM TRANSFER Leondro B. Ferndndez Sdinz, Erardo Herrera, Jose M. Bajo, Harry J. Mallard. SENER, S.A., Dept. Aeroespacial. Madrid, Spain.

The scanning elements of the radiometers for sun-synchronous, Earth Resources Missions need to be scanned in an accurate and reproducible manner, not only because of linearity,repeatibility and pointing stability, but also because their oscillatory motion must not introduce intolerable disturbances to other satellite- mounted instruments.

With these considerations in mind a development model has been designed, built and actually tested under cover of an ESA contract.

The model consists of the following units: Mirror, Compensating Inertia, Motor, Sensor, Control Electronics and Off-Loading.

Both the Mirror and Compensating Inertia are mounted on Flexural Pivots (Bendix) and they oscillate within an active range of -6 degrees at a nominal frequency of 8.4 Hz, but in phase opposition. The turn-around is produced by cantilever spring bumpers attached to the Compensating Inertia.

The loss of energy taking place during the collisions is compen- sated in each semicycle by a pancake torque motor (Aeroflex) actua- ting on the Compensating Inertia to minimize the disturbance on the Mirror.

Two pancake optical encoders (Heindenhaim), 18000 lines,constitute the sensing unit which give the necessary signals for the Control.

The electronics perform the control of the velocity, the position and the frequency of the motion, and also provide the necessary scan information during tests and generate the motor driving signal. - 101 -

To protect the OSMA against the launching environment, an Off-Loading mechanism has been incorporated into the design and is released by means of two pyrotechnic cutters.

The paper will present the design and performance requirements, the final configuration (If/eight 11.38 Kg) and the design criteria, with particular emphasis on the materials used. (Carbon Fibre- Delrin for the collision points; material being used to dump out the remaining vibration on the bumper spring between collision, etc.)

The difficulties found with the different components and those found during performance will be discussed. (Assembly of the pivots, number of lines in the encoders, influence of the inertia on the frequency of the motion, induced vibration of the structure by the collisions on the bumpers, jitter, etc.)

The modifications necessary to overcome the shortcomings in the initial design and during tests will be explained in detail.

The results of the tests will be compared with the requested per- formance (Steady state power below 15 Watts). The test equipment will also be described.

Finally it will be demonstrated that the concept of two inertia* moving in phase opposition to cancel out the momentum transfer is a valid one. - 102 -

IAF-83-111 PANORAMIC IMAGING BLOCK FOR SPACE P. Greguss Applied Biophysics Laboratory,Technical University Budapest Panoramic imaging systems which render "pictorial rep- resentation encyclinfi the spectator* (after Webster's Dic- tionary) have been known since 1878, when Mangin, a French astronomer, constructed his first panoramic stellar tele- scope. The latest model was developed by Space Systems Research Labs for the Naval Training Equipment Center, Or- lando, Florida, in the late seventies. These systems use either scanning techniques, i.e., the panoramic image is a result of rotating conventional imaging optics, or the pan- oramic image is formed by a single shot as a result of com- bination of lenses and mirrors. Independently of the im- aging method used, these solutions are so sophisticated that their application as space optical sensors are techni- cally prohibitive. The scope of this presentation is to describe and demonstrate in functioning an imaging block developed in our laboratory, which could be used for 360° panoramic imaging in space.

The basic problem of both the panoramic imaging and the reconstruction of the recorded image issues from the fact that a cylindrical volume has to be projected onto a 2-D surface. It follows from the definition of panoramic imaging that the resulting image must have a 360° horizon- tal field angle, while the vertical field angle is the sum of the field angles below the horizon and above the hori- zon. It can be shown that the resulting 2-D image will be a plane ring image with the width of the vertical field angle, and in this the radial lines represent vertical field angles, and concentrical rings represent varying ho- rizontal field angles at constant vertical field angles.

Our single-block panoramic imaging system is the com- bination of diversely shaped refracting and reflecting sur- faces, which, if properly designed, is capable of recording, in a single shot a 360° panoramic image of the space around its optical axis. Since in the formation of the resulting ring-shaped image a relatively large volume in the center part of the imaging block has no role at all, it can be removed. The resulting imaging block looks like a donut, thus we named it "panoramic donut lens*, PDL. Naturally, the non-image-forming part of the imaging block is not nec- essarily to be removed, it can be used as a part of another optical system, e.g., as a part of a fish-eye lens which, then, covers that viewing angle in the direction of the op- tical axis which is originally excluded from the viewing - 103 -

angle of the PDL. Depending upon the material from which the PDL Is manufactured, panoramic Images can be recorded In UV, visible and IR. In order to have ultimate performance the shape of the refractive and reflecting surfaces should be aspherlc, preferably parabolic, which means that practical difficul- ties in the production of these surfaces with high degree of precision required arise. However, after computer sim- ulation studies we have found that the manufacturing costs of our PDL can considerably be reduced if a certain - well defined - degree of image quality reduction is permissible. In this case, some of the parabolic surfaces can be re- placed by the so-called "best fit" spheres according to a formula we have developed. The image created by PDL gives the viewer an extraor- dinary experience of seeing in every direction, however, with some restriction in the vertical viewing angle. 2he examination of such an image makes it clear that when the cylindrical space is flattened this way, two things are mapped onto the representation plane$ 1. the perspective image of the cylindrical space (with the above restriction), 2. the visual world imaged exhibits no boundaries or breaks of any kind, similarly to the visual world surround- ing us, nevertheless, one has to turn himself to perceive the entire space, although its interpretation needs some exercise and experience. However, by projecting such a ring image through a similar PDL onto a cylindrical screen, the distortions issuing from the principles of the Imaging mechanism itself disappear, and the spectator gets the im- pression as if he himself would stand in the center of the space imaged. IAP - 83 - 112

NEW GENERATION OF SPECTROMETERS FOR MfcASUREMKNTS OF SI'KCTRAL REFLECTIVE CHARACTERISTICS Mlshev D,N.,Krumov A.Ch.,Potkov D.I.,Tsonov D.Ch.,Zhivkov S.K..

A review is made on the phylosophy of the design of ground- based multichannel spectrometers for measurements of solar radiation,reflected from various natural formations within the visible nnd the near infrared ranges of the electromagnetic spectrum.Important specifics of the new generation of the ground spectrometers are the improved functional possibilities for the management of the scientific experiments and TOT the specialized processing of the obtained da.ta»The instumonts enable performance both in automated nio.de of operation and within the payload of complex measurement equipment.The incor- poration of proper computer techniques provides for the increa- sed lnteligenoe and adaptivity ,which nafegwrards the precise resolution of scientific,methodological and applicable tasks* - 105 - IAP-83-113 BAS - the project of an earth-atmosphere-speotroptaoto- meter for basic research by Or. Ulrich Leiterer and Dr. Michael We Her DDR-1231 lindenberg, Aerologisches Observatorium des Meteorologischen Dienstee der DDR Summary: The earth-atmosphere-spectrophotometer BAS is intended to be used for basic research in the field of remote sensing. The main advantages of BAS are the possi- bility of a high-accuracy calibration in absolute units utilizing the extraterrestrial spectral solar energy dis- tribution end its simultaneous use for radiance and for irradiance measurements; e.g. the same spectrophotometer BAS to measure immediately one after the other the high irradiances of the sun (transmission measurement) and "ae- ry low radiances of water surfaces. Data evaluation will be made immediately by the BAS-lin- ked computer for field measurements. Further important technical parameters of BAS are the scanning of the spectral range 0,38 to 1,12 /um in 40 steps within 3 s, a mean half-band width of 12 nm for each step, working temperature range from -20 °C to +40 °Gt low mass of about 4 kg, power supply by rechargeable bat- tery pack, remote control gear up to 20 m distance. BAS is also suited for measurements to be made from airbor- ne and shipbome platforms as in trackless desert* and high mountain regions. Different applications are shown by some examples, e.g. for transmission factor, total optical depth, aerosol depth, irradiance, radiance, directed reflection coeffi- cient, albedo, indicatrix and eontreat. - 106 «

IAF-.83-114

iNFORMATHlN EXTRACTION FROM THEMATIC M/M'PHR DATA

Edward Lee Til ton, II!

National Aeronautics and Space Administration National Space Technology Laboratories NSTI-, Mississippi 39529 U.S.A.

The Landsat-4 spacecraft, launched on July 9, 1982, is eqtilppiul witli 3 rnw electro-optical sensor expected to advance the remote sensing < ap.iH 1M i»"» of Earth resources satellites. An experimental instiument, I he Tli<

Over the past decade, land cover mapping has been conducted with n<1 IIM t t solar energy in the green, red and near infrared portions of the flcririinn;; netic spectrum with an 80-meter instantaneous field of view (IFOV). By w-in this mul ti-spectr.'.l capability, Landsat specialists have shown that it is possible to apply objectivej digital data processing techniques to del int-.-it»' a wide variety of surface cover in an efficient and highly repetitive In^'s.

However, the TM contains significeptly narrower hands in the same r^Kl'1" <3!; the MSS. Also, new spectral intervals are being sampled, intervals not pi» viously available for remote sensing analysis. The Increased numhei avnl narrower bands should measure surface phenomena more precisely than pvei before. In addition, the TM's spatial resolution (1FOV) has been impnived. Covering an area 1/7 the area of the MSS, the TM will allow smaller fen!ores on the surface to be observed. Finally, the improvement in radiometric re- solution is noteworthy. The TM is designed for eight-bit digUiznt J->n (2 *H> levels) compared to the seven-bit digitization (64 levels) of the MSS. Tin- increased sensitivity, complementing the spatial and spectral performam-p parameters should dramatically enhance the overall performance IFVPI to -a degree not experienced before with earth viewing sensors^

Scientists at NASA, National Space Technology Laboratories {NSTI-), Farrb Resources Laboratory (ERL) conducted an evaluation of l.andsat l> TM data, soon after its launch, to examine the potential of this new electro opt>« il sensor for providing Improved Information for renewable resources and land cover studies. Investigations of TM data included forested wetland, urhaii and agricultural land covers using a scene of data collected over Arkansas and Tennessee on August 22, 1982. Standard digital Information extract inn techniques were employed and classification accuracies were assessed for p-»« l> application study area.

1. A unique wetland ecosystem Jn northwestern Tennessee was ssle« !*<1 i" evaluate the TM's capabilities for delineating forested wetland land tv»«*>r types. The extremely heterogeneous area encompasses a lake with npe'i uah'r. - 107 -

floating aquatics and emergent vegetation and is surrounded with transition grasses, brush, and forested cover types Including cypress, mixed hardwoods, and mixed willow/cypress.

2. Categorization within urban land cover from space has not been successfully achieved with traditional optical sensors. These complex, spectrally and spatially diverse phenomena, represent a particular area of interest for TM investigators. Within the August TM scene, a small city of < 15,000 population in northwestern Tennessee was selected to test the TM data characteristics. Six specific urban land covers were classified in- cluding commercial/industrial, residential, agriculture/bare soil, transition/ grassland, forested land, and roads/inert materials, employing only spectral analysis procedures.

3. TM data were evaluated for mapping agricultural land covers over a study area previously mapped with MSS data. The area Is a well managed homo- geneous agricultural region with the primary crops including rice, soybeans, wheat, and to a lesser degree grain sorghum, and hay.

The investigations discussed in this paper have examined the digital classi- fication of TM data for three land cover applications. In each case, the accuracies achieved with a single date TM data set exceeded a 90% correct confidence level. The improved spectral and spatial properties of the TM data expand previous earth observing capabilities. The urban example alone demonstrates that it is possible to classify complex urban components where formerly an urban area the size of the one examined could barely be digitally or visually discriminated from MSS data.

Although the TM offers a significant improvement in spectral resolutions over what has previously been available on the Landsat MBS, the increased spatial resolution of the TM presents even more interesting opportunities for research. Since the TM is a new electro-optical sensor, it is axiomatic that further work be conducted to understand the spectral properties and characteristics of the system. T-o fully exploit the capabilities of the TM, however, both the spectral and spatial attributes of the data must be examined. The next step in the evaluation process, therefore, should assess the interrelation- ships of these factors by employing new spectral pattern recognition tech- niques along with spatial, textural and contextural classifiers.

In summary, the investigations described in this paper have explored the capabilities of TM data for discriminating land covers within three particular cultural and ecological realms. Although the work presented here has been initial in scope, the results indicate how useful the Landsat-4 TM will be in providing researchers with a new capability to monitor the Earth1s environ- ment and landscape. ^- 108 - IAF-83-II5 SOVIET EARTH AMD ATMOSPHERE REMOTE SENSING SPACE VEHICLES N.N.SHEREMETYEVSKY, JU.V.TRIFONOV, INTERCOSMOS COUNCIL AN USSR.

1, LAST YEARS THE USSR HAS INTENSIVELY DEVELOPED THE EARTH AND ATMOSPHERE REMOTE SPACE TECHNOLOGY BOTH FOR HYDROMETEOROLOGY AND FOR THE EARTH AND OCEAN RESOURCES RESEARCH. THESE DEVELOPMENT WORKS HAD EXPERIMENTAL AND OPERATIONAL STAGES, THE REPORT DEALS WITH THE MAIN CHARACTERISTICS OF THE SOVIET SPACE VEHICLES AND THEIR INFORMATION - METERING COMPLEXES JUST AS ALREADY IN USE SO UNDER DEVELOPMENT FOR THE USE IN THE NEAR FUTURE, 2. IT IS POINTED OUT THAT AT PRESENT IN THE FIELD OF SPACE SYSTEMS FOR HYDROMETEOROLOGICAL PURPOSES THE USSR OPERATES METEOSYSTEM NAMED METEOR-2 , WICH PRINCIPALLY DIFFERS FROM THE EARLIER GENERATION SYSTEM AS FOR THE QUALITY OF THE OBTAINED INFORMATION,, SO TO THE SCOPE OF THE MEASURED PARAMETERS. "METEOR-2 VEHICLE, ITS BLOCK-DIAGRAM AND DESIGN PROVIDE HIGH RELIABILITY, MORE PRECISE ATTITUDE CONTROL AND MORE POWERFUL ENERGY SUPPLY, SO THIS VEHICLE MAY BE USED AS A BASE ONE FOR FUTURE DEVELOPMENT OF ITS INFORMATIONAL CHARACTERISTICS, THE REPORT GIVES DATA,CONCERNING COMPONENTS COMPRISING TETEOR-2" SYSTEM AS WELL AS THE VOLUME AND PARAMETERS OF THE GLOBAL AND LOCAL METEOINFORMATION,OBTAINED FROM THE SYSTEM CONSISTING OF THE THREE VEHICLES. ALSO TRENDS OF FUTURE DEVELOPMENT OF SPACE METEO- ROLOGICAL SYSTEMS USING BOTH LOW-ORBIT VEHICLES v. RETEOR-2 TYPE) AND GEO-STATIONARY METEOROLOGICAL SATELLITES ARE CONSIDERED IN THE REPORT. 3. AS FAR AS SPACE VEHICLES FOR EARTH RESOURCES RESEARCH IS CONCERNED IT IS SAID THAT THE SOVIET VEHICLES OF THE FIRST GENERATION FOR SUCH PURPOSES LAUNCHED IN ACCORDANCE WITH THE METEOR-PRIRODA PROGRAM HAD BEEN BASED ON THE EXPERIENCE GAINED IN USING METEO- ROLOGICAL INFORMATION FOR GEOLOGY AND OTHER BRANCHES OF ECONOMY. FOR THESE REASONS THE SPACE VEHICLES ARE EQUIPPEI WITH MULTISPECTRAL DEVICES OF LOW RESOLUTION (0.2-0.I KM) AND WIDE FPV, SPACE VEHICLES LAUNCHED TO THE SUN-SYNCHRONOUS ORBIT AND EQUIPPED WITH ELECTRO- JET THRUSTERS FOR ACCURATE ORBITAL CORRECTION HAVE BEEN SUCCESSFULLY OPERATING UNTIL NOW, AND THE INFORMATION OBTAINED IS WIDELY USED IN THE INTERESTS OF VARIOUS BRANCHES OF NATIONAL ECONOMY, E.G. POLAR FLEET* FORESTRY AND GEOLOGY. As A RESULT OF REALIZATION OF EXPERIMENTAL AND OPERATIONAL WORKS TO RESEARCH EARTH RESOURCES FROM SPACE THE USSR HAS BEGUN PREPARATORY WORKS AIMED AT THE DEVELOPMENT OF THE CONSTANTLY OPERATING EARTH RESOURCES RESEARCH SYSTEMS WITH HIGH INFORMATION CAPABILITIES USING ELECTRO-MECHANICAL SCANNERS. THE PA- RAMETERS OF A PERSPECTIVE SPACE VEHICLES FOR EARTH - 109 -

RESOURCES RESEARCH ARE GIVEN IN THE REPORT. AT THE FIRST STAGE OF DEVELOPING OF SUCH A SYSTEM TEST FLIGHTS OF A NEW EXPERIMENTAL SECOND GENERATION SPACE VEHICLE WITH THE MULTISPECTRAL SYSTEM FRAGMENT (OF UP TO 8C M RESOLUTION) TOGETHER WITH SOME OTHER INFORMATION EQUIPMENT ON-BOARD WERE HELD IN 1980. IT IS POINTED OUT THAT THIS SPACE VEHICLE AND THE FRAGMENT SYSTEM HAVE BEEN SUCCESSFULLY OPERATING UP TO NOW; AND MAIN RESULTS OF OBTAINED DATA APPLICATION IN AGRICULTURE ARE LISTED. H, FOR A VARIETY OF ASPECTS CONCERNING THE DEVELOP- MENT OF THE REMOTE SENSING DEVICES THE USSR PERFORMS SUCCESSFUL CO-OPERATION WITH SOCIALIST COUNTRIES WITHIN THE BOUNDS OF THE INTERCQSMOS COUNCIL. IT IS OUTLINED IN THE REPORT THAT THE USSR SUCCESSFULLY CO-OPERATES WITH THE DDR INSTITUTES IN THE FIELDS OF CONSTRUCTION AND TESTING OF FACILITIES USING FOURIER SPECTROMETER-INTERFERO- METER DESIGNED FOR PROCESSING OF RECOVERY METHODS OF ATMOSPHERE HUMIDITY PROFILES, AS WELL AS IN THE FIELD OF DEVELOPMENT OF THE FRAGMENT EQUIPMENT. A PARTICULAR ATTENTION IN THE REPORT IS PAID THE CONTENTS AND RESULTS OF THE SOVIET-BULGARIAN CO-OPERATION IN DEVELOPING THE UNIQUI SPECTROMETER AND UNF EQUIPMENT FOR EARTH RESOURCES RESEARCH VEHICLES DESIGNED BY BULGARIAN SCIENTISTS AND TO THE SUCCESSFUL OPERATION FOR MORE THAN 1,0 YEARS ON-BOARD OF THE SOVIET HETEOR-PRIRODA SPACE VEHICLE. SUCH A CO-OPERATION, IT IS SAID, IS PERSPECTIVE AND IMPORTANT. - 110 -

IAF-83-117 ESA'S PLANS FOR FUTURE EARTH OBSERVATION PROGRAMMES

Dr. J.N. de Villiera European Space Agency

The European Space Agency is studying a variety of potential future satellite missions in Earth Observation. In the field of remote sensing of the oceans the ERS-1 satellite, described in detail in other papers, and projected for a 1988 launch, has now completed its Phase B. A second flight model is anticipated, and recent studies have examined ways of augmenting the capability in the area of ocean colour monitoring. The mission of *ny advanced land observation satellite must take account of the particular requirements and constraints in a European context, and the need to advance beyond the scope of the existing and approved land missions of other countries. , Europe's contribution to the World Weather Watch, will continue to provide data until 199^/6 through an Operational Programme. For the period beyond this, preliminary studies have examined options and scenarios, particularly in the areas of short term forecasting ("nowcasting"). The problems of climatology and atmospheric research often become global in nature. Observations by a system of instruments ara needed. Emphasis has been given to defining the characteristics of such systems before commencing instrument definition work. Such systems would be effectively realised by embarking instruments on a Buitable aet of other satellites. For other area* a single satellite, or payload, would be sufficient. The physics of the solid earth has a variety of objectives of which the majority that space techniques might address could be covered by an appropriate precise point positioning satellite mission. Studies have determined the feasibility of a satellite concept for addressing at the centimetre levelt moqitoring of crustal distortion in earthquake areas determination of inter and intra tectonic plate motions monitoring the kinematics of the earth's rotation precise determination of points on the earth's surface. - Ill -

Thie satellite concept, P0P5AT, combines many of the advantnqes rjf existing space techniques without incurring their disadventaqeR. In particular, a high orbit and all weather precise rarcqe end range rate tracking are used. The tracking technique is planned tn be tp.Hted on the F.RS-1 satellite. The First Spacelab payload recently launched included two iPinotr sensing experiments. The follow-on European Retrievable f,'nrrier (F.URECA) may have application to Earth Observation missions not needing more than about 6 mnnthn in orbit, but able tn benefit from retrievability. - 112 -

IAF 83-119

CO-OPERATION TO ACHIEVE A GLOBAL METEOROLOGICAL SATELLITE SYSTEM

JOHN A. LEESE World Meteorological Organization (WMO) Geneva, Switzerland

ABSTRACT

Meteoiological satellites present an outstanding example foi the theme of the thirty-fourth International Astronautical Coiujiess i.e. "Co-operation in Space". The present network of polar-orbiti mj and geostationary meteorological satellites represents nearly ?b years of international co-operation. This network produces meteorological data which can be acquired through direct braodcas*. from satellites by more than 1000 stations located in 125 countries. The meteorological community and its international organization (WWi) are striving to find ways to assure the continuous availability of and access to satellite meteorological data.

The final report of the Second United Nations Conference mi the Exploration and Peaceful Uses of Outer Space (UNISPACE-82, Vienna, 9-21 August 1982) stressed that all countries should :,-ontj ni;e to have access to meteorological data. To fulfill this objective, the Conference made the following recommendations to WMOi

To undertake a study concerning the possibility ot setting uj an international structure providing continuous availability of and access to satellite meteorological data;

- To ensure optimal use of space techniques. In particular, in the related aspects of facilities for data reception and processing, data analysis and data disseminationi

To continue its examination of the feasibility of setting uj. regional or international centres for meteorological data reception and analysis.

The recommendations of UNISPACE-82, noted above, present e formidable challenge to WMO and its Members if we are to successfully achieve a highly reliable and continuously operating global meteorological satellite system.

It is instructive to examine also the role that interneticnal co-operation played in the development of the current satellite network. Meteorologist? were very enthusiastic from the start of Hie - 115 -

"space age" more than 25 years ago about the potential benefits that could t>e gained by viewing the weather patterns from high above the earth in a properly equipped artifical satellite. However, it took a tremendous effort by many persons in a number of international bodies to achieve the network of meteorological satellites which exists today. Examples of specific actions by WMO, the UN General Assembly and other international bodies aie described in the complete paper. These actions together with other international collaboration resulted in the establishment of the Global Atmospheric Research Programme (GARP). GARP envisaged large-scale atmospheric data-gathering projects requiring multinational support. Extensive national and international planning was undertaken, aimed at developing the support required to carry out these projects successfully, in particular, for developing the essential satellite meteorological systems. The meteorological satellite system developed for and operated during the GARP Global Weathei Experiment in 1979 demonstrated a significant impact on the accuracies achieved in numerical weather prediction.

We can now see that the peak of operational satellite activity to date occurred in 1979, as part of the field phase of the Global Weather Experiment (First GARP Global Experiment - FGGE). Duri a that period there were five geostationary satellites plus the pole -orb- -intj satellites operated by the USSK and the USA. It shou J be noted that this level of satellite activity has not been achit ' d since aovember 1979. Our view of these problems could be great ., influenced by where we live on the earth and oui personal knowledge of budget plans by the countries or consortium of countries now operating meteorological satellites. However, there would probably be a full agreement among us that the operational continuation of meteorological satellites should be ensured by all means.

The fundamental problem we now face is therefore how do we assure the continued and reliable operation to provide the existing capability to the worldwide user community. In order to define an approach to solving this high priority problem of operational continuity, we need to identify practical means - with sane alternative options - of contributing to a co-operative system. For an initial analysis of future international co-operation it should suffice to examine some possibilities for the goals, financing, management, future technology projections, system configurations and operational scenarios of such an operational system. The focus of this effort should be an operational meteorological satellite system capability during a ten-year period beginning about 1990. Consideration should also be given to the development of a conceptual outline for an operational system around the year 2000. Such a concept should provide a target that is sufficiently long range to provide the time needed to develop a new generation of operating satellites if that approach can provide appropriate advantages over other approaches. r Ai- HI i.!'i

STUDIES ON .JAPAN'S EARTH RESOURCE SATELl.Iir.-1 (KRS-1)

Yasushl llorfknwa & Hideo Ohha National Space Development Agency of lapan

ABSTRACT

Earth Id-source Satellite Is very useful to ciiMccl. r.'irth resource data, wi«l«*lv, effectively and economically. There are many de.1?! rements for satellite plan;; In this aspects from users. To develop and realize such earth lesoutcp sali'Mitc by minimarizing user's requirements contribute to international i-onppr.it ton hv offering collected data from satellite.

From this view point", NASDA started the studies on Japan's Earth Resource S ,i I • • 3 11 Le Programme called as ERS-1 from 1980. Recently, we finished It1? 'onceptuni .ind preliminary design phase. This paper relates to the teibniral del ail <>f ERS-1 design.

Mission objectives of ERS-1 are to establish active microwave sensing t<-< hnlijiip and to collect Information of geological features, land use, agriculture, Inrpili fishery, environment preservation, coastal zone monitoring, etc.

KRS-I is supposed to be launched !>y H-l rocket which is under development liy NASDA, from Tanegashlma Space Center.

Main Instruments for observation are synthetic aperture radar (SAR) and viilUlf and near Infrared radiometer (VNR). As for SAR, its radar frequency Is I.-batul, observation swath width is 75 km, spatial resolution is 25 m x 25 m, otf ra>li» angle is 33 degrees and data transmission rate is 60 Mbps.

As for VNR, observation band is four spectrum bands of visible and near intrari-.i, spatic.-il resolution Is 25 in x 25 m, observation swath width is 150 km an.] daM transmission rate is 60 Mlips.

Further information will be described in detail in the paper. NASDrt lias slarivi the research of critical technologies fir both sensors since 1981.

ERS-1 Is deslRiifid also to carry data recorder for storing data from hot It spn«j«>

ERS-1 orbit in about 5f>!3 km altitude and 97.7 degrees Inclination, sun syiirlno and near recurrent. Local time at descending node is 10:30 am * 10 minutes.

Attitude control of spacecraft Is three axis stabilization. Spacerrafl has .ibn e.lght box modules mounted on box shaped frame structural supports.

Spacecraft weight is about 1400 kg. SAR antenna and solar array padle will be deployed in early orli It phase.. Thesp sizes are 12 m long and 2 m wide and 5 m long and 2 m wide, respectively. - 115 -

Solar patlle i.s canted to achieve effective power supply. Since spacecraft is designed separable between observation instruments portion and bus equipments portion, taking into account of,testing and transportation, primary studies are posed on the'feasibility of structural, and thermal design.

SAR and VNR data are transmitted through 8 GHz TWTA transmitter and could be received by typical Landsat data receiving stations.

Spacecraft is controlled by s-band tracking, telemetering and commanding system and also planned to use TDRS.system for early orbit phase as a back up of s-hand system.

Cower System has 1500 W solar power generation and 80 AH battery capability.

Life time Is -nUlcipated to 2 years.

In «rde.r to realize FR.S-1, many basic technologies are under study. For example, not only SAR an<) VNR hul als>i, data transmitter, attitude control system and data handling system, t!tc. art; studied. Some of these are tested by using hre-id bn.-ird model. Each subsystem of FHS-I will be developed by several Japanese companies separately. - 116 -

IAF-83-121 Tropical Earth Resources Satellite (TERS) Ir. Albert P. Hoeke* ; Ir. Mahsun Irsyam** * Netherlands Agency for Aerospace Programmes (NTVR) ** Indonesian National Institute of Aeronautics and Space (LAPAN)

The idea for a Tropical Earth Resources Satellite (TERS) was one of the options when the Netherlands Institute for Aerospace Programmes (NIVR), in cooperation with Dutch industries, was studying a successor for the second Netherlands Astronomical Satellite (IRAS), launched on 25 January 1983. A workshop held in Indonesia concluded that the TERS idea is feasible and at present the TERS concept is being studied by the NIVR and the Indonesian National Institute of Aeronautics and Space (LAPAN) in a joint phase A study.

The baseline of the TERS concept is a remote sensing satellite with a pushbroom optical instrument in a high true-equatorial orbit. The zero degree inclination orbit at an altitude of 1680 km will have an orbit period of 120 minutes. The 100 km swath-width of the sensor instrument can be pointed anywhere between 10° northern and 10° southern latitude, which will offer the equatorial countries an opportunity to observe a specific part of their territory within this TERS coverage four times per day. The high cloud cover percentage in the tropics will reduce this frequency, but a forward looking cloud sensor will give the possibility to detect what specific area is free of clouds and to point the instrument field of view accordingly.

-The TERS, which is conceived for the equatorial countries and Indonesia in particular, will complement the already existing and planned remote sensing satellites, especially with regard to the improvement of the temporal resolution of the remote sensing data on these countries. Apart from the disadvantage of the high percentage of cloud cover, the equatorial countries do not have the advantage of the increasing overlap to the poles which positively influences the temporal resolution of the near-polar orbiting satellites in countries farther from the equator.

The benefits of the TERS system are not necessarily limited to Indonesia. Other countries around the equator in Asia, Africa and Latin American/the Caribbean may also be interested in utilizing the TERS- system. It is anticipated that after the feasibility studies other countries can take part in the development of the TERS system. During the exploitation phase a participating country will have user control over the sensor operations when the TERS is covering its territory. The country or a group of countries could transmit to the TERS on- board computer a "shopping list". This satellite operation programme contains data on where to point the swath-widhth at a certain longitude. Furthermore a priority-tabel of areas on the same longitude will be included in this- shopping list. Should the area with priority 1 be clouded the swath-width can be pointed to priority 2 {3 to n). - 117 -

It is anticipated tliat the Ti:ns will tie compatible with other remote sensing satellites in order to make optimum use of already existing remote sensing data receiving and processing facilities.

TERS concept

orbital velocity Jikmls

observation instrument

cloud detector

"equator - 118 -

Reference number of paper : IAF-83-122 Title : Satellite based Remote Sensing Program - A perspective in the Indian Context Name of aut'r~>r s S.Kalyanaraman Organisation : ISRO Satellite Centre, Bangalore, INDIA

The Indian Space Research Programme is tuned to the goal of applications in the fields of Communications, Meteorology and Remote Sensing for resources survey and management to aid the national development. All other objectives like development of satellite and launch vehicle technologies are set to achieve the basic goal.

With the natural resources management being one of the important components of any national development, India is in the process of planning a National Natural Resources Management system with the help of satellite based remote sensing, supplemented by aerial surveys and other conven- tional methods. India, being a vast and a developing country with its economy dominated by agriculture, forestry and mining, requires relevant timely and accurate resources information to provide a data base for appropriate resources management planning.

As a part of this, satellite based remote sensing programme has already been initiated and the experimental phase has been successfully completed with the help of two Indian built satellites - BHASKARA-I and BHASKARA-Il, launched in 1979 and 1981. These satellites provided TV imageries in visible and near infrared bands with a resolu- tion of 1 km and passive microwave imageries in 19,22 and 31 GHz bands. Several months of TV imagery data have been collected, analysed and thematic maps were prepared and distributed to users for possible applications in the areas of land use, geology, forestry, geomorphoiogy and snow cover study. Similarly microwave sensor data was used for estimation of water vapour and liquid water content,rainfall rates over seas surrounding India and determination of sea surface winds. The BHASKARA projects have given Indian Space Research Organisation (ISRO) a total system capability on an experimental basis in the area of resource sensing from space. Additionally, the development and launching of various other Indian satellites including a three axis stabilised experimental communication satellite called APP E, has provided the needed technology base towards development of sophisticated satellite platforms for remote sensing with higher resolution requirements.

Observing the potential in resource survey and manage- ment with the help of satellite imageries, Government of India - 119 -

set up a National Remote Sensing Agency in 1975 and this has provided opportunities for aerial remote sensing of selected areas and also acquisition, processing and dissemination of Landsat-2 and 3, TIROS-N, NOAA-6 and 7 satellite imageries. With this experience, ISRO has taken up the next step of development of semi-operational satellite based remote sensing system to be realised in eighties. Such a system is planned to provide benefits with the generation of resource information in a number of areas such as agriculture, forestry, geology and hydrology. The Indian Remote Sensing Satellite (IRS-lA) slated for launch during 1985-86 will be a forerunner in this direction. IRS-lA, a three axis stabilised satellite, being built in India will be placed in a sun synchronous orbit of 904 km altitude with the help of a soviet launcher. It will provide imageries in four bands in visible and near infrared regions with resolutions of 73 and 37.5 m. The payloads will use CCD sensors working in 'push broom1 mode. The data will be transmitted in X and S bands and received by a ground station centrally located in Indian territory. From this data, Browse, Standard and Precision products will be generated to service the needs of the user agencies in the country.

IRS-lA represents the first of a series of operational remote sensing satellites planned for the country. The next variants of IRS will use the same 'bus' to provide better geometric and spectral resolutions, with the help of improved sensors. The microwave remote sensing developmental studies are being pursued in ISRO and out of this will emerge future microwave remote sensing payloads to be added to the system towards the end of this decade. - 120 -

IAF-83-123 SATELLITE IMAGE PROCESSING FOR A SMALL COUNTRY: THE HUNGARIAN CASE T.HAj6s, G.BOTTNER, F.CSILLAG, A.SZILAGYI FOtDMERESI INTEZET Remote Sensing Department Budapest, Hungary

The area of Hungary (93.000 km ) can be covered with 10 LANDSAT images. The average number of cloud-free 200 days per year provides favourable conditions for remote sensing observations in optical wavelengths. The whole country is well-mapped, several detailed and generalized survey data are available from topography to geology. Therefore satellite images are thought to be primary use in change-detection as well as in the monitoring of natu- ral arid artificial process of different scales in time and apace. Based on international experiences a satellite image processing methodology has been developed. Avialable sa- tellite data, reference data types in relation to the dynamics of the examined phenomena and visual interpre- tation methods are briefly touched. Detailed description will be given on our image processing software (IPS) developed on a general purpose computer with a large core, a great number of usual peripheries and an extended re- mote terminal network. The principal concept of the software is to facilitate the Basic multispectral image processing in a non-inter- active way, by minimizing the number of human decisions as much as possible during the processing* The IPS environment consists of data files (image library, ancil- lary data) on one hand, and register files (image, sta- tistical, GCP and usage registers) on the other. Wide variety of image formats are allowed to input to or out- put from IPS, including all commonly used data families (BSQ, BIL, BIP). The image processing software consist of a TALK part to define interactively the desired activity on an alpha- numeric display, and an EXECUTE part to run it in real- -time or batch, depending on computer resources needed. Thanks to the user-friendly dialogue the usage of IPS requires some knowledge of remote.sensing only, and not computer programming. - 121 -

The function set of IPS is divided into three group*: register, application and job handling function*. The application functions serve for image transfer, radio- metric and geometric transformations, data compression, statistical analysis, clustering, classification and post processing. The main features of all functions are reported as well. The application examples illustrate the present capa- bilities of IPS: single- and multi-date classification with spatial mask for agricultural lenduse and cluste- ring with spectral mask for water-management. At last a Landsat-4 TM processing result is presented. - 122 -

APT/TIP/WEFAX receiving and processing system

GYGRGY, letvan - PINTER, Ferenc Institute for Atmospheric Physics of Hungarian Meteorolo- gical Service

The space originated data have definitly increasing role in the science of meteorology as well as in the operative prectice.The system of polar orbiting and geostationary meteorological satellites give usable, continous and glo*- imL information about the weather of the Earth.The effi- cient application of the data needs a computer based ground system.Data transmission of the meteorological satellites has been received for 15 years at the Insti- tute for Atmospheric Physics.Hardware and software deve- lopment carried out in the last year makes it possible to receive and process APT and TIP data of polar orbi- ting satellites NOAA as well as WEFAX transmission of the geostationary Meteosat-2. According to these the receiving system cons sts of three parts.APT transmissions are received with an om- nidirectional quadriphilar antennawith a gain of 2.5dBI. Because of its omnidirectional characteristic this an- tenna needs no controlling and tracking, and it is pos- sible to receive two satellites at the same tine.The receive region of the antenna is about a 2600 km radius area round Budapest.A high-gain quagi antenna system is used for receiving the digital TIP data in 137 MH* range. The WEFAX transmission is received with an S-band parabola.The operative APT and WEFAX reception is based on a stored-program-controlled, programmable real-time - 123 -

clock.This equipment stores a menu consisting of 16 selectable 24-hor programs with the time of the recep- tion of the WEFAX transmission.The real-time clock serves for the timing of the APT receiving system, too* The equipment produces time reference signal for the computer for further processing of data.

This processing of the data needs a special picture processing configuration.In the last years such a com- puter system has bean developed, too.It is based on a small CII-10010 computer extended with special equip- ments as black-white and colour displays, Huirhead K-300 hard copy unit furthermore an interface to the receiving system.This configuration is an on-line in- teractive system for processing of the meteorological data given by satellites.After the on-line entering of the data various picture processing procedures can be performed as filtering, enhancement, temperature and brightness calibration, geographical identifica- tion and water-vapour correction.As a result of the interactive processing wide range of the products can be obtained, e.g.: soil and ser.-surface temperature maps, percentage cloud cover, height and thickness of cloudiness.The raw and proceased data is stored in data base.Processed pictures for archiving are output via a D/JS converter unit to the facsimile recorder. - 124 -

J 1l*-83-125 A Development of High Speed Image Processing System TIAS 3000 H.SHINODA, I.FUJITAKA, K.FUKUE and T.SAKATA Tokai University Research and Information Center 2-28-4 Tanigaya, Shibuya-ku, Tokyo 151, JAPAN

ABSTRACT TIAS(Tokai Image Analysis System) 3000 is conposed of five sub- systems. They are 1)solid state disk, 2)high resolution display, 3)high speed arithmetic processor, 4)display manory and 5)controller. It is intended to achieve interactive image processing tasks of remotly sensed data with the aid of the host general purpose image processing system TIAS 2000. The largest problem in a high speed processor is the data transfer speed. None of existing large capacity memories can meet to the high data rate. TIAS 3000 has solved this problem with the aid of solid state large memory buffer consisted of dynamic RAMs. The capacity of this solid state disk will be 400-1600 M bytes. It can be considered as three dimensional image planes from outside the buffer. High speed arithmetic processors are attached to this manory buffer. Memories are connected to three data buses, i.e., CIV, P and D buses. Their access speeds are 500, 60, and 17 nsec, respectively. D bus is a the bus for high resolution display. P bus data are usually used for arithmetic operations and CPU bus is mainly used for data I/O with the host system. Accesses to the memory data are done through an independent address control processor. This processor can generate not only special addressings for displays (zooming, windowing, etc), but also addressings for several kinds of image processings with the aid of pre-storaged address pattern memories. Far instance, butterfly addresses of two dimensional FVT's can be generated, hence it can largely increase the processing speed. Display memories are conposed of image meonris and graphic memories. The basic unit of the image memory is 1024x1024x8 bits, which is called an image plane. TIAS 3000 has 8 .image planes, i.e, 64 bits for each pixel. It can also be used as 16, 32 or 64 bits planes. 32 or 64 bits planes can be used as a buffer of floating point or complex data. It also meet the requirements of IANDSAT-D thematic mapper (TM). As the TO has 7 bands, remaining one plane can be used as the storege of processed results. - 125 -

B'or graphic displays such as characters or line graphics, the basic unit is 1024x1024x1 bit plane. It is called as a graphic plane and 16 graphic planes are installed in TIAS 3000. These planes can also be used as two planes each containing 256 color coded results. There are three kinds of arithmetic and/or logical processors in TIAS 3000. They are ALU arrays, function memories and pipelined floating point processors. ALU arrays are composed of 9 multipliers, 19 ALU's and high speed parameter memories. It is mainly used for spatial processings,e.g. spatial convolutions. Function memory unit has 16 bits input and 16 bits output, which corresponds to 128k bytes. It is used for variable transformations. Floating point processeors are pipelined 32 bits processors and maximum 8 of these processors can be installed. They are mainly used for maximum likelihood classifi- cations and FFT's. The basic display specifications are 1125 lines/frame, 30 frame/sec, and 1:2 interlace. However it has several other display modes. The most important one in these modes is a OTSC mode which can act as an interface to conventional video system. The internal control of this system is made by a microprogramable controller using bit sliced micro processors. Microprograms are stored in read only memories and read/write memories (Writable Control Store). The display subsystem is oontroled by a HJ68000 based micro processor. It handles display systems as well as interactive processings. The front end processor of this system is a HP 2113E minicomputer and it does the total control of the system, and act as an interface the hast image processing system TIAS 2000. As a conclusion, TIAS 3000 will be one of the fastest image processer in the world and can meet the requirements of caning era of operational remote sensing data processings. - 126 -

IAF-83-126 A Development of Interactive Image Processing Software System TIPE K.FUKUE, H.SMMODA and T.SAKATA

Tckai University Research and Information Center 2-28-4 Tonigaya, Shibuya-Ku, Tokyo 153, JAPAN

ABSTRACT In the field of remote sensing, the recent growth of digital image processing has created a need for development of a fully user oriented software system which manages the number of accumulated image processing programs and image data. In general, the softwares of an image processing systun include processing packages and a monitor section. However, conventional monitors have not sufficient flexibility, expandability and easy-handling capability. TIPE has been developnent to overcome these problems. The monitor of TTPE consists of following three subsystems ; (1) A scheduling, system including a scheduler and menu files. (2) A control parameter management system including a control Parameter management module and control parameter files. (3) A catalog system including a catalog management module, catalog files and a header management module. Main tasks of monitor section are a procedure control and a data management. In order to improve a flexibility, an expan-dability and an easy-handling capability of the image processing software system, it is necessary that system components are independent each other and that an image data base is established for the data management. In order to split these system components, the above three subsystems of TIPE were designed. Scheduling system is based upon menu files which are hierar- chicaly organized. A system manager needs only to modify or generate a menu file for the change of programs or procedures. In addition, TIPE user can select a proper menu file which has the most suitable structure for his processing purpose. In the control parameter management system, control parameter parameters are stored in a disc file called a control parameter file. Image processing programs usually require interactive inputs of various control parameters. When a series of programs is repeatedly scheduled, TIPE user need not to input most of these parameters and can select a proper control parameter file which has the most suitable processing procedure for his processing purpose. - 127 -

TIPE maintains digital image informations in a form named TSF (TRIC standard Format). The catalog systan and the TSP establish a image data base that allows the system to maintain the image files automatically. Attributes of image files are stored in catalog files and they can be retrieved by using owner-member relationship among images. With the configuration of TIPE described above, the great deel of flexibility and expandability were achieved. Further-more easy- handling capability was achieved by providing a image data base concept and the control parameter system. - 128 -

IAF-83-127

NASA/NOAA Implementation of the USAID-Sponsored Satellite Ground Station and Data Processing Facility for Bangladesh

J. C. Dodge National Aeronautics and Space Administration Washington, DC, USA

and

C. H. Vermillion Goddard Space Flight Center Greenbelt, MD, USA

ABSTRACT

The U.S. National Aeronautics and Space Administration is implementing a cooperative, interagency program of technological aid to the Bangladesh Space Research and Remote Sensing Organization (SPARRSO) for the purpose of developing a local capability to receive, process, and interpret meteorological/hydrological data as well as to interpret pre-recorded digital tapes of LANDSAT data to improve the planning and management of resources related to agriculture and water development.

This paper will describe the remote sensing facility, its value to Bangladesh, the satellite data products, the complex interagency and international cooperation involved, and the special training requirements involved with introducing this type of technology to new and distant users.

A series of two, related projects have been sponsored by the U.S. Agency for International Development for implementation by NASA at SPARRSO in Bangladesh. The first concerned reception arid display of both polar orbiting and geostationary data to enable improved tracking of the frequent and often deadly cyclones which pu. h a storm surge tide northward into the Bay of Bengal. This project was called the Bangladesh Disaster Alert System and wa3 successfully implemented in December 1981. - 129 -

The second and more comprehensive project is currently underway and is entitled, "Agro-Climatic/Environmental Monitoring." Thi3 project goes beyond the first by providing a computerized satellite data interpretation system and the use of remotely- located Data Collection Platforms (DCP) for receipt of hydrological, meteorological and tide data.

The NASA implementation effort is a complete package which involves U.S. hardware and software procurement, local Bangladesh materials procurement, factory and on-the-job operator/technician training, maintenance training, and consultant visits for in-depth local training concerning data interpretation.

The intended uses of the equipment and training provided by these projects involve the areas of agriculture, meteorology, water development, and fisheries. Of particular concern is (a) the interaction of the weather and food production in terms of early identification of seasonal floods, drought, and storm damage; (b) the secular changes in land and water resources caused by shifts in the size and locations of rivers, (c) the patterns of siltation and the emergence of new land, particularly in the Bay of Bengal; and an assessment of the development potential of the forested areas and fish habitats.

Hardware for the second phase of this project is scheduled to be installed in December 1984, with final checkout by February 1985. A year of training follows by both an in-country consultant and a visiting consultant lecture/ demonstration series.

At the completion of final, in-country training, the Bangladesh scientists and technologists will have the equipment and expertise that will allow them to use a combination of satellite and ground-based observations to identify and plan for local changes in their own environment to the public benefit of the inhabitants of Bangladesh. In addition, the fine remote sensing facility established there can make SPARRSO a regional, high-technology training and learning center. - 130 -

1AF-83-128 The Swedish SPOT Data Acquisition and Processing System Gunnar Larsson Scandinavian Satellite Image Corporation

1. Background information about Swedish Space Corporation/ Scandinavian Satellite Image Corporation.

- History of SSC/SSIC - Purpose of the creation of SSIC - Connections to other parties

2. The SPOT space segment

- Spacecraft characteristics - Orbit

3. The Data Acquisition Subsystem

- Operations

- Equipment

4. The Bulk Processing System

- SPOT Standard Product description - Volumes - Operations - Data Management 5. The Precision Processing System - Precision Product description - Operations 6. Future Plans and Developments - 131 -

IAH-83-I30 PRINCIPLES OP ORGANIZATION OP TI1E ON-GROUND DATA PROCES- SING K)R REL1OTE SENSING PURPOSES USING FINITE RINGS AND FIELDS M.A.Rakov, L.V.Varichenko Institute of Phyaica and Mechanics, Academy of Sciences of the Ukr.SSR Moat of the modern digital on-ground data proces- sing systems for remote sensing purposes operates with both digital and analog signals under the comples num- bers field C , because the values of both digital and analog signals may be represented as subsets of this fi- eld. Such an approach takes great computing and hardwa- ve volumes. For the signal defined on the finit range N ( N = O,I,...n-I) most of the algorythmes demand the number of operations proportional to log. H, N, M and even to greater powers of H. That is why the problem of building up of the mathematical model of data processing system demanding minute number of calculations when it is modelled on computer ia very urgent, as well as the problem of organization of computer procedure. The building up of the model using performances un- der the field C is not always necessary. These perfor- mances may be defined also under another (abstract) fi- elds, e.g. under finite field GF(p) or finit residue ring moduli M, Zm. In order to perform this it is nece- ssary that the input and output data values were the subsets of GF(p) or Zm. Such condition is accomplished in the set of cases when single-dimension signal is pro- cessed and practically always when two-dimension signal (image) is processed. Such approach gives a set of fol- lowing advantages: - the realization of arythmetic operations is sim- plified, what leads to the risen qualities of producti- vity and diminishing of hardware volume; - the possibility arise of dividing dynamic range of input signal values on subranges and parallel pro- cessing; - all the assotiative, distributive and commutati- ve laws of operations in GF(p) or Zm are conserved by computer processing, what facilitate the software rea- lization; - using of fields and rings with finite performan- ces restricts the number of computations. All mentioned advantages are discussed in the pa- per both with the limitations of such approach. A set of data processing system models is presented which use finite fields and rings for the designation of per- formances, and for them tne.grinciDles pr correspon- ding on-ground data processing syBxemB hardwares are also sing r '^jc I'M I, i OP null,!!. J I, run perform linvir t «'{>nii-1 r i <• foirri'i fi OHM of MIP Jm^/e, noii'o nii|>iw*>t'u1iiK l"Hinil "IV - 133 -

INTERNATIONAL DATA EXCJIANGE: A STUDY OF DIFFICULTIES Y. Zonov Intercusmoa Council, USSR Academy of Sciencen Remote sensing of Earth Resources and the Environment by apace meana is starting t.c be widely uaml by national economy management apparatus of many countries. Internatio- nal cooperation in space data r-onf!_..\.'ti on and distribution is developing actively. At the same time the combination of some specific cha- racteristics of natural resources and apar-e ourveya may be a cause for some difficulties in unhampered distribution and use of primary and processed apace data. The main reason for this is that political boundaries of regions containing natural resources and do not present barriers for their movement (including antropo/;enic pollu- tion which may be considered as some "negative resource"). A number of possible situations when the flow of pri- mary and secondary remote sensing space data may be harop*'- red are presented: # More than one country are engaged in exploitation of a divisible natural resources but do not have equal pos- sibilities in using space data. # Formation of a natural resources takes place in one country but it is exploited by another. # Existance of territories the rights to which are disputed by a number of countries. # Environmental pollution is created in one country and is transported to another (transboundary pollution). # Effects of natural disasters on the state of eco- nomy of various countries. IAF - 83 - 13?

THE PART TAKEN BY FOREIGN STATIONS IN THE UTILIZATION OF THE FRENCH REMOTE SENSING SATELLITE SPOT

ABSTRACT

Gilbert CALES C.N.E.S. TOULOUSE - 135 -

The operation of SPOT satellite is based on the utilization of two types of ima- ge receiving station networks : - The first, called "centralized" network Is composed of two Image receiving stations and two associated preprocessing centers : one in TOULOUSE (FRANCE), the other 1n KIRUNA (SWEDEN). Their production being exclusively reserved to SPOT IMAGE Company, (and the corresponding SWEDISH corpora- tion) : this company 1s specialized In the distributing and marketing of SPOT products. - The second network might.be called "decentralized", as it 1s composed of several Image receiving stations Implanted around the world. Their produc- tion Is mainly used to meet their own needs. There is another Important difference between the two networks : both TOULOUSE and KIRUNA stations are able to receive scenes from all over the world, thanks to the on-board recorder, whereas the other stations are only fitted to receive data telemetry of images in "direct readout" as 1t Is gathered by the satellite, corresponding to a visibility circular area within a radius of 2500 km approxi- matively around the involved station.

After recalling the main characteristics of SPOT orbit and of the SPOT on-board instruments (called HRV in french) : . in the panchromatic band : resolution of 10 m ; . in the spectral bands : resolution of 20 m ; . width of the swath : 60 km ; the general organization of the ground system, for SPOT operations, is descri- bed, pointing to the fact that the general coordination Is ensured by the SPOT MISSION CONTROL CENTER, located In TOULOUSE and manned by CNES. Generally users of SPOT products have to ask SPOT IMAGE, which request the CNES to perform the adequate satellite programmation. However, foreign stations, after signing a contract with SPOT IMAGE, will be al- lowed to request their own programmet1on directly of the Mission Center. The receiving capacity of a station depends on a lot of factors, mainly : . the aera of emerging land within the range of common visibility satellite-station ; . the station latitude with sunlight features and the phenomenon of nearing of orbits around the poles.

A judicious distribution of reception stations around the globe would allow to Improve the programmation and thus the utilization of SPOT SATELLITE. - 136 -

Application of "pact' Imagery for the .'Study of Aiithropogeni r> Pollution ami Ft.:- Lmpact on t.ho Knv i

Yα.A. Israel, Yu.V. Novikov, Yu.A. Afanasiov ftnvi ronment ami Climate Monitoring Lai.oral m y , Moscow, HSKR

At. present the problem of monitor ing ttv1 inanniado hol- lution and its impart on thf env i ronnient i" being wci'ic >) out within the framework of both int urnati HUH 1 and UHI imi^l programs and agree/fieri In. Thin problem is becoming vinrc- ui-i more pressing, despite the Fafit. tha t much effort is mado ••• reduce the level of pollution. At the present stage it is already cotisiiln-iMi po.-:-. ii. i< to initiate the development of a first-generation .sp^c ,"yr- tem for monitoring manmade pollution and its effects on ' \,<- envi ronment. This decision is based on the ana lysi r< of ! |). folJ owi ng factors: - highly informative mul t ispectra 1 imagery (J"-t*i hi,-:.1' and medium resolution), obtained from t.he "Salyut" nwrui-fi stations and the "Meteor-Priroda" sat"] 1 Hop, - availability of interactive data processing and .MI .- lysis techniques, and - possibility to make corroborative ground-truth mea- surements for a number of parameters. Such a system will provide data oi: certain parsim^u-v- of air, water and land pollution on a global scale. The newly developed technique of space imagery jnai.v- sis may be of great use in the investigation if wa'» >• qua- lity. With apriori information and short-term ground-truth measurements available, continuous monitoring of state and regime of water bodies can be accomplished and various pol- lution areas detected and investigated both in continental and ocean waters. When studying the air quality of urbanized regions tl.- developed technique allows to: - delineate areals of relative anthropogenic pol- lution; - determine the average background level of p«>11ut ion in the area; - find the background zones within the area; - identify zones with various degrees of pollution load; - estimate the area of zones with various pollution levels and monitor their dynamics. These techniques make it possible to draw up maps of relative anthropogenic pollution and its impact on th-^ na- tural environment on a global scale and maps of ha areas. - 137 -

IAF-83-135

Vegetation Status Assessment and Monitoring in Agricultural Areas by Remote Sensing G. Csornai, J. Vamosi, 0. Dalia, A. Gothaf Institute for Geodesy and Cartography Budapest, Hungary

First the special Hungarian conditions and factors In the agriculture and remote sensing are outlined. Not only the climate, terrain and soils pattern are specific, but the pattern of the crop growing technology as well. Summa- rizing all the factors a brief review of demands of agri- culture hoped to be solved by remote sensing is given. All requirements of data acquisition, distribution and proces- sing are listed discussing the ways how present remote sen- sing technology could respond to demands. Within our circumstances the importance of general land use maps are somewhat smaller. On the other hand the intensive agriculture needs a quick, reliable and econo- mical feedback loop to get real time information on the condition of large scale grown crops. Together with the present and possible application areas of crop status assessment the role of monitoring is emphasized. Limited by the special Hungarian conditions, brief account of "problem-classes" and the necessary data acquisition frequency, geometrical and spectral resolution throughput requirements of the processing system are discussed. Based on our experience a short overwiev on the feasible applications from different problem-classest soil management, inland water effects, crop deseases and effects of cultivation is given. Especially those methods necessary to asses the con- dition of crops at a certain growing stage and monitoring the changes of vegetation are emphasized. After summarizing the data acquisition and processing methods on system level we report the results of a case study. The complement type input data of low altitude multiband photos and Landsat MSS were used. The ground truth and reference data were updated by aerial multiband photos thus giving support to classifi- cation training. With the help of a Landsat MSS time series from the vegetation growing period we could conduct an eva- luation and classification of data by computer. A useful tool developed to assess and locate of different types of In-field lnhomogeneities is Introduced. Results of evalua- tion are presented underlining main points and experiences that can be generalized in order to proximate to an effec- tive and reliable remotely sensed data based system which could serve for economic monitoring of most important ag- ricultural phenomena. - 138 -

IAF-83-137 Hater Quality Monitoring of Lake Balaton Using LAND9AT MSS Data

H.SHIHODA, K.ETAYA, T.SAKATA Tokai University Research and Information Center 2-28-4 Tomigaya, Shibuya-ku, Tokyo 151, JAPAN and L. Goda Research Center for Water Resources Development(VITUKI) H-1095 Budapest IX. Kavassay Jeno U.I., Hungary

ABSTRACT

Hater quality monitoring of Lake Balaton in Hungary was done using LANDSAT MSS data. First step of the data analysis was preprocessings. In LANDSAT MSS data, there exists striping noises which has occurred by the mismatching of detector responses. This striping noise has heavy influences especially on water quality monitoring because of its low reflectance. These noises were carefully eliminated using following three algorithm : Driiean and variance matching, 2}dither, 3)histogram matching. After this destriping procedure, the image was geometrically corrected.

Ground truth was done simultaneously with the data acquisision of LANDSAT MS5. Data collected are as follows : Dchlorofyl concentration, 2)turbidity, 3)suspended solids, 4)transparency, 5)water temperature, 6)organic matter concentration, 7)extinction coefficient, 8)COD. Multi-regressional analyses were made between these ground truth data and MSS data. Both the original values of MSS data and normalized data between four bands were used for the analysis.

As a result, normalized data showed better corre- lation compared to the original data. In the items measured on the ground, suspended solids and transparency showed strong correlation to the MSS data. - 139 - IAF - 83 - 138

APPLICATION OF TRACK SPECTROMETHIC STUDIES IN IMAGE PROCESSING FOR REMOTE SENSING PURPOSES

This paper In view of remote sensing etaova the evolution of the structure of multiaMnali image* in the combination with track spect- rametrio etudles.Th* structural agreement of the two> type* atf Images regarding: coiauir and* texture- specific* result* In increase- of the element identification accuracy from, trade to- reference: imege.Thie enable* the- performance of lnter-extrapoilatlee of the precis* eartlmar tes.The etructuraX evo>Lutl.«n 1* represented with the- detailed des- cription of the local earth foreatdons.The method suggested provide* for- composition, of colour and peeedo—coloor Image* with enhanced spectrometrie propertle* by larse-band scanner scenes.An «ddltl«nal poseeibility fov operational evaluation o>f the inter-orbital paraoi*-' t«rs 1* ehoMn,Th*> d*T*l*>paient of taei method 1* given tor *teree-ima-i gee ( for example: SPOT) and fov dynamic variation* of th*> stndlo* objects* The caapatatlan proceduro 1* applied, on sceno* frost tandaat and Meteox-Pxlxoria 25 aatoLUte* and Bulgaria T300-II experiment fear the? territory of BttLgaria.Tb* reeulst from the Identification step are- shown for *w» main types of remot* sensing: from automatic sate~ lllte* and In the caset of manned flight* — for arbitrary track geo- metry. The structural evolution 1* developed through generation of intermedlat* mutant structure* over- the variety, corresponding to the soene and the iterative- evaluation of the quality.

As a whaAe,the method suggested demonstrates the possibility of the precis* track epeetxomstric measurement* on the earth eurfaeo to decrease- the UBdetermlnanoy In the separation of -variou* type* of earth formations by image of low. spivctral resolution. - 140 -

Paper No. IAF-83-141 Multiphase Combustion Experimentation In Microgravity Ty A. L. Berlad Energy Center, University of California LaJolla, California 92093 and State University of Nev; York Stony Brook, New York 11794

At normal gravitational conditions, multiphase combus- tion processes may involve gravitational settling of the heavier-than-air fuel elements as well as natural convec- tion effects on the combustion process and associated flow fields. Where gravitational settling and natural convection (at g=1) compromise our ability to successfully carry oni specific fundamental studies, other methods of study must I>P employed. In some cases, it is found that combustion stu- dies under microgravity conditions permit the experimental resolution of centrally important combustion issues that otherwise appear intractable. It is for such cases that reduced gravity combustion experimentation is particularly valuable.

For several decades, various investigators (Ref. 1-7) have assessed the potential worth of combustion experimen- tation at reduced gravitational conditions. In a number of cases, successful experimentation has provided important new results. In all of these investigations, the importance to the understanding of combustion in a space orbit environment has been clear. Perhaps more important, however, is the val ue of these studies to the understanding of combustion under normal gravitational conditions (Ref. A,7). In this paper, we briefly review the broad range of cases for which combustion experimentation under micrograv- ity conditions can be employed to achieve otherwise inacces sible understanding for both normal and modified gravitation- al conditions. Particular emphases is placed, however, on discussion of multiphase combustion processes. The combustion processes selected for emphasis here are: autoignition of clouds of premixed fuel particulates in a quiescent oxidizing gaseous atmosphere; flame propagation and extinction for clouds of premixed fuel particulates in a quiescent oxidizing gaseous atmosphere; as well as a number of other combustion - I'll -

phenomena for which heterogeneous rate processes are of key importance.

References

(1) S. Kumagal and I. Hiroshi: Combustion of Fuel Droplets In A Failing Chamber. Proc. Sixth Symposium (Interna-" tional) On Combustion, p. 726. Rheinholu* Pubi . Corp. (1957).

(2) J. H. Kimzey, W. R. Downs, and C. H. Eldred: Flaimnabil- ity In A Zero-Gravity Environment. NASA-TR 246 (1966) ."'

(3) T. H. Cochran and W. J. Massica: An Investigation of Gravity Effects On Laminar Gas-Jet DiffusionT'lames. Thirteenth Svmposium (International) On Combustion. p. 821. The Comb. Institute (1970).

(4) A. L. Berlad, C. Huggett, F. Kaufman, G. Markstein, H. B. Palmer, and C. H. Yang: Study of Combustion Ex- periments In Space. NASA-CR-134744 (Nov. 1974TT

(5) M. Lavid and A. L. Berlad: Gravitational Effects On Chemically Reacting Boundary Layer Flows Over A Hori- zontal Flat"Plate. Sixteenth Symposium (International) On Combustion, p. 1557. The Comb. Institute (1976).

(6) A. L. Berlad: Gravitational Effects On Combustion. Pro gress In Astronautics and Aeronautics 5_2, p. 89 (1977)

(7) T. H. Cochran (Editor): Combustion Experiments In A Zero-Gravity Laboratory. Vol. 73 of Progress in Astro- nautics and Aeronautics (1981). IAF-83-144 RECENT DEVELOPMENTS IN SURFACE-TENSION DRIVEN INSTABILITIES G. LEBON, Institute or Physics, B5, Liege University, Belgium. Convective instability driven by surface tension efFeels i" an infinite horizontal fluid layer heated from below is studied. This effect is generally referred under the name of Marangoni insi ahi1itv When a thin fluid layer initially at rest is subject to a tempetafm» gradient, motion is induced when the temperature difference tendipn a critical value. Moreover, convection assumes cellular forms which in the steady regime appear as regular roll or hexagonal patients. In micro-gravity, the cells take the form of hexagones with » vett1 cal axis of symmetry. Mathematically, the problem can be treated by various appmn ches. The present note is devoted to a survey of three widely tisfl techniques, namely the normal mode, the energy and Malkus-Vertinis iterative method. The normal mode technique, a typical Hiu.ii thf-o ry, is essentially aimed at providing the neutral stability solution under infinitesimally small perturbations. The energy method, as proposed by Reynolds and Orr, and revisited recently by Sen in and Joseph is applicable to large perturbations but yields only global, .and generally too conservative, conditions of stability. Tti-= itein tive methods appear more attractive as they predict the hehaviom of the system beyond the critical point of instability. (I is shown that the above mentioned methods provide satisfactory agn»euif»nl s with experimental observations. In particular, the values of thf l parameters and the shape of the flow patterns are ronfirnipri .»«ppri- mentally. J A K-B J-147 ON UOMii I'JUJBLKMS OK UliNTKAJj-oYMMIiTKY. OUMVKUTION SIMULATION UNDKH MKJKOUKAV IT* CONDITION.

l.M. Yavoi'skaya*, ¥u.N.Bel,yHev**, A . H.BogoyavleriHki * • iipace Reaearch Institute, Ui-WR Academy of Ho i.enceM. ** Institute of Mechanics! Moscow State University. Moscow, U.'JHK

At the previous lAI? Congress a possibility of simulation of central-symmetry convection under wicrogravity conditi- ons using the dielectrophoretic force in liquid dielect- rics waa discussed. It appears l;o be p. unique possibility for experimental inveatigation of convection in spherical layers under central-symmetry force field. The problem seems to be very important for understanding the origin of differential rotation and large-ouaLe r,rHiiul»;« in the solar p?iotosphere as well as a band structure and equato- rial jets in the atmospheres of giant plan«tn.

Two preliminary problems have been solved up to now. Pirwt, for testing an experimental technique being used in neur- zero gravity conditions, the laboratory set-up lias been developed. The set-up permits an investigation of the velo- city field, the sequence of instabilities and turbulence onset in a spherical shear fluid flow over a wide range of similarity parameters. Some recommendations for experiment in microgravity conditions are given.

Second, when a central-symmetry convection in rotating spherical layers is simulated the effect of centrifugal forces, which may be neglected in most astrophysics! en- sea should be taken into consideration. The problem of the central-symmetry convective instability in plowly ro- tating spherical layers with centrifugal force taken into account has been solved. The results are discussed and the estimates of similarity parameters needed to conduct pro- per and adequate experiments in inioro^ravity are presen- ted . - 144 -

IAF-83-149 NON-SIMILAR MARANGONI BOUNDARY IAYERS L.G. NAPOLITANO, G. RUSSO Institute of Aerodynamics "U. Nobile", Univ. of Naples (ITALY)

The senior author has disclosed (1), (2) the existence of new types of dissipative layers, which he called Marangoni Boundary Layers, which may occur along the liquid-gas or liquid-liquid interfaces in free con- vective motions induced by gradients of surface tension. As a first step towards the investigation of the structure and features of Maran- goni boundary layers the similar solutions of plane configurations have been studied for the uncoupled (3) and coupled (4) isobaric case. The present paper reports results of the continued analysis of Marango- ni boundarylayers and deals with the general case of non-similar plane layers driven by thermal gradients of the surface tension. The perti- nent field equations are solved by means of an extension and generali?a tion of the Method of Integral Relations (MIR). Interpolating and weight functions are taken to be a finite subset of an arbitrary complete set of functions in the L2 space, orthonorma1i7erl with respect to different inner products related to the structure of the integrals appearing in the MIR.The influence on the accuracy of thp solution of the different definitions of the inner products and, for a given inner products, of the different set of orthonormal functions from arbitrary rotations and/or reflections of the basic set obtained through the Gram-Schmidt procedure, are discussed in general and with specific reference to polinomials in the tangential velocity. The resulting set of non-linear ordinary differential equations consist of the inteqral form of the momentum and energy equations for the two interfacingfluids.They are strongly coupled througtethe boundaryiconditicri' at the interface. Solution procedure are deviced, which tend to reduce this coupling. The actual numerical solutions is then obtained by stan dard methods. Comparison with similar solutions given in (2) and (3) shows that the proposed generalization of MIR yields extremely accurate result? pvpn with very limited number n of "strips" (n=4 or 5) when the appropriate inner products and appropriate orthonormal sets are used. The method is then applied to the solutions of indicative non-similar cases characterized by given distributions of the "outher" temperatures in the two interfacing fluids.Velocity and temperature profiles are found , their features discussed and their dependence on the problems data (physical properties of the fluids and of their interface, impose'* tanperature gradients) is analysed in terms of the previously introdu- ced (4) "adiabatic temperature distribution".

REFERENCES 1) L.G. Napolitano: "Microgravitational fluid dynamics", invited lectu- re, 2nd Levitch Conference, New York Nov. 1978. 2) L.G. Napolitano: "Marangoni boundary layers", Proc. 3rd Symposium on Matrial Sciences in Space, Grenoble 1979, ESA SP-14?' 3) L.G. Napolitano, C. Golia: "Similar plane tiaramjonH'Oumlnry layprs", 3rd Levitch Conference, Madrid 1980. 4) L.G. Napolitano, C. Golia: "Coupled Marangoni bounday layers", IAF Congress, Tokyo 1980, also Acta Astronautica, VoJ. 7, 19K1. - 146 -

IAF-83-150

ORDER OF MAGNITUDE ANALYSIS OF CONVECTIVE EFFECTS. IN DENDRITIC SOLIDIFICATION

M.D. Vignon, D. Camel and J.J. Favier Centre d1Etudes Nucleaires, Grenoble (France)

The different types of convectlve phenomena which may occur during the dendritic solidification of metallic alloys are discussed from an order of magnitude analysis £1J. Bulk thermal (or forced) convection and/or interdendritic solutal convection have to be .considered according to the values of the experimental data, particularly : alloy concentra-

tion c, overall thermal gradient G and its horizontal component. GH, gra- vity level, growth rate F, liquidus slope m^ thermal and solutal expan-

sion coefficients /3T and /3C, diffusivities v and-D. Scaling laws for tlv solute boundary laypr resulting from bulk thermal (or forced) c-onvf-nJtion have already been derived £2-3j# On the other hand, the interdfjndrit.Jc flow depends on a solutal (Jrashof number based oh the horizontal density

gradient and a characteristic length L9 which is of the order of the 2 liquid channels width, i.e. : Gr* = 0C GH g L*/i< mL. For Gr < 1 , which is generally verified in practical cases, the iriterdendritic fluw velo-

city v is given by : v L9/ v => GΓ. This a-priori law comparet? favorably with the results of horizontal solidification experiments where the mean interdendritic flow velocity has been estimated from the resulting mm- sured macrosegregation. In these experiments, as well as for mos<. liori - zontal -dendritic solidificat.ions of metallic alloys at 1 g, th<=- rati<-> v/R is of order one. In order to cajicel the interdendritic flow • effects,' 'this ratio has to be lowered by one order of magnitude. According to

[l] L.fi. Napolltano, IAF-81-126, Rome 6-12 Sept. 1981 [2] D. Camel and J.J. Favier, J. Crystal Growth 61 (1983) 125 [3] D. Camel and J.J'. Favier, submitted to J. Crystal Growth. - 147 -

JAF-83-151 Preliminary Results of Texus 8 Experiments on Effects of Surface Tension Minimum G. PETRE, M.C1. FONTAINE, J.CI. LEHHOS University Libre de Bruxelles

For aqueous fatty alcohol solutions, the equilibrium surface tension (against air) versus the terror rat lire at constant mole fractions presents a minimum (temperature Tm) It can be expected that in such systems a surface tem- perature gradient induces surface movements from "hoi" to "cold" parts of the surface at temperatures under Tm, and from "cold" to "hot" above Tm. The Texus 8 (TEM 06/6) experiment was intended to pro- duce and observe under microgravity movements from the "cold" to the "hot" part of a liquid/gas interface. The selected system was an aqueous solution of n-hepta- nol 0.00624 molal. The solution was introduced under microyravity, together with tracer particles, in a cell of 3cmx2cmxlcm. The four small sides of the cell Ocmxlcm and 2cmxlcm) are in stainless steel the two greater walls are 0,8 cm thick pyrex plates, each with a teflon coated grove parellel to the 3cm sides. The designed geometry succeeded to create a stable liquid/gas interface, using nearly 3cm3 of solution which were confined in one half of the cell (Scmxlcmxlcm) between two "lateral walls" keeped at temperature of 45°C and 65°C e respectively (above Tm a 40 C). ("Lateral walls":2cmxlcm) The movements induced by the temperature gradient were observed in the same cell on earth and under microgravity. The observations may be summarised as follows s - While on earth two contrarotative liquid convection cells appear in the system, under microgravity only one convection cell appears in the whole liquid volume, induced by a surface movement from "cold" to "hot" surface regions. - The surface movements are much slower in micrograviry than on earth. A possible explanation could be a modification of gas phase convection and surface evaporation conditions when the gravity is suppressed. IAF-83-152 LICUID-PilASE SINTERING IN MICROGKAVITY P.M. Ossi & P. Rossitto CKSNEF - PoHtecnioo d.i MiIdno llnly R. Rdberti & G. Silva Diiartinento dl Chijnica Fisici Appi iivit.i Politecnico di Mi lano Italy

This paper presents a study performed on the first stage of ns »tv\ wires. The foroe-balanoe equation is studied to evaluate the vaiious contributions for the different irodel configurations. T(>e menturns shapes are evaluated by integrating the Youny-.Laplace equation. As the first stage of the process is considered, the results apply •«• both misclble and immiscible systems. An analysis of tJw: role of I he linuid volume fraction on the packing of identical splieres is also carried out. Closed-form and numerical solutions are presents! rind tIn- stability conditions for the liaiiid bridges durinq tt*» i-parrati'itwipnt phase are worked out in a sinple graphical, way. Ground and f Light experiments have been performed on Oie elassic.il W/Ag and W/Cu systems. Several samples with different powder gpnmHiy (spherical or jagged) and dimensions and different. J inn Id plww> w>1 im»-- fractions have been inserted in Boron Nitride crucibles HIKI P»CXK in the isothermal zone of the furnace. The flight experiment has included in the TEXUS 8 sounding rocket payload within thf R5iA Mi gravity Progranme. First experimental results supfxort thp f>ff«-«-t of tlie capillary forces In tlie first staqe of the pro«*».SR atn) ili^ shrinkage anisotrnpy observed in the gorund experiiwritB I'an l«- id to tlie gravity effects on the liriuid phase. 'If>e analysis of »}*> re stills is in progress. IAP-83-153

THIS GROWTH OP GaSb IK MICRO-GRAVITY CONDITION

I.Gyuro*, E.Lendvay+, J.Gyulai++, T.Gorog+, M.Harsy*, M.Ranky++, J.Glber+++, L.Bori+++, L**

L.L.Regel, N.A.JCulehicki.1, V.T.Hrjapor Institute of Cosmical Research of ;5A3

During the joint Soviet-Hungarian space fligth /27th May - 2nd June, 1980/ project Eotvos was aimed to study the growth of semiconductor materials; among them the crystallisation of GaSb from melt, - in mlcro-graTity conditions, The GaSb ingot grown in the furnace "Iristal" on board of Saljut-6 was examined by different nethods such as optical - and electron nicroscopy. X-ray analysis, electron channelling, SIMS, X-ray fluorescence and electrical measurements, as well. The Material prooved to be a bicrystal of which signi- ficant parts did not wet the quarts ampoule and showed an unconfined solidification. These freely grown sections gave a perfect ion backscattering pattern, indicati-ng a clean, amorphous layer f^ee and defect free surface.

+ Research Institute for Technical Physics of HAS ++Central Research Institute for Physics of HAS Physical Institute of Technical UniTereity of Budapest - 150 -

IAF-83-154 Reference number of paper: Some results of the space metallurgy program "HliAUUCA"

E.U.Puuha*, A.Roduz**, G.Buza*, Katalin Hodvogiier**

Iron and Ufceel Research and Development KjiUiPprij-je, Hudapeat Teclmical University for Heavy industry, Miulcnl.c

At the accayion of the joint .Soviet-Hungarian f)pah formation and the shape conserving role of oxide nltijj.s. The first results as well as the theoretical considerationa on convection with the Al-allbys conlainin. 4% Cu have already been published in different papers tm>\ lectures. Here in interesteing result in connection with the Al-specimen covered by Cu will be described. The Cu-covered Al-specimen melted on the board nf the "Salyut 6" during the joint Soviet-IIungarian nprv-e flight were suitable for the determinatioii of the d.i Ci u.sjo coefficient of Ou in the melted Al. The arranging (Gu-~cover, Al-core) as well as the oxide akin on the Al prevented the development of the Marangony flow. Thn concentration distribution in the specimen WHM deterinJj-.-'d by means of a microprobe and on the basin c" struotin ' testing. Using the Smith's finite different method ;hn diffusion process was simulated by a computer. When t) calculated and measured values were compared, the f>'lowing most probable diffusion coefficient wan - 151 -

received for the diffusion of Cu in Belted Al.

= 5.1O"2 exp (- £|p£ ) cm2/a

On the baais of the calculations a new specimen- -geometry was worked out for the following experiments, which ia more advantegoua from the point of view of the examination of the diffusion processes* - 152 -

83-157 Results of Japanese Space Processing Experiments Using the TT-500A Rocket

K.Kajiwara, T.MaLsuda, Y.Shibato, T.Masuda, l.Akirooto

National Space Development Agency of Japan

The National Space Development Agency of Japan has been carrying out space processing experiments under the microgravity enviroment using the TT-500A rocket.

The TT-500A, used for this experimental series, is a two stage solid rocket with overall length of 10.5m, diameter of 0.5m. It is capable of carrying a payload of about 330kg to an altitude of '300km. The payload consists of experimental equipments, tracking and telemetry systems, atitude control systems, and a recovery system. The payload section is separated, after the second stage motor burn-out at about 50 sec from the lift off. After the separation, the release system of yo-yo despiners and the rate control system are activated to reduce the payload section spin rate. When the rate decreases low enough, an enviroment of less than 10^% is achieved. The payload section is kept in this microgravity condition for about 6 minutes. While the descending mode of the payload section, it is tracked along its radio signal by a ship and two airplanes, and then it is recovered by a ship finally.

The first TT-500A was launched in September, 1980. This test flight was almost successful. The atitude control systems insufficiently functioned, but a low gravity condition was obtained. During this condition for about 6 minutes, the experiments were conducted as planned. And the recovery system operated normally, so that the equipments and test pieces were recovered. Following this test flights, two flights were carried out in 1981 with experimental devices for Ni-alloy and Amorphous semi-conductor processing in space. In both flights the atitude control systems worked sufficiently, so that the microgravity enviroment of less than 10~Tg, according to telemetry data obtained, was realized. However the payloads were not recovered due to malfunction of the recovery system. After the investigation of the cause of these failures, the redesign and improvement were carried out on the rocket and on-board equipments. - 155 -.

The fourth TT-500A was launched in August, 1982. All events during the flight were executed as planned. This flight was a test flight for recovery system with two electric furnaces on board; one is for Ni-alloy, the other is for Amorphous semi-conductor. These material processing experiments were conducted under the microgravity enviroment of less than 10 g. And the payload section softly decended on the sea by parachutes. The fifth TT-500A was launched in January, 1983. This flight was perfect, and the payload section was recovered. It flew a material processing experiment and a lightening experiment equipment of halogenous lamps on board. The furnaces temperature was controlled as programmed under the microgravity enviroment of less than 10"%. Halogenous lamps were lightened by voltage and current as set in advance. This paper presents a brief description of these space processing experiments. Also, the TT-500A rocket system, the result of past flights, and experimental equipments are described. # # # - 154 -

IAP-83-I58 SOME PECULIARITIES OF SOLIDIFICATION PROCESS OP THE BINARY MELT UNDER M1CHOGRAVITY CONDITIONS L.L. Regel, Nguen Thanh Nghi, A.M.Du- rachenko, V.A. Dchanibecov Space Research Institute, the USSR Aca- demy °f Sciences L. Oyunbullig Physics and Technic Institute the MPR Academy of Sciences

In the first part of thia work the analysis of a number of ex- periments on the growth of semiconductor binary compounds and alloys in the nSalyut-6" orbital station is taken out for the exposure of their general regularity. It is shown that in several case the crystal growth process in microgravity occurs under larger than on the Earth, initial melt supercooling, that can lead to the significant changes in mor- phology and structure of the space-grown ingots were observed. Another peculiarity is revealed in the process of bubble for- mation and migration in the melt. The BigTe-j-BipSe^ eystem is considered as an example. It is also established that during the growth of some semiconductor alloye the periodic composi- tion distribution with large amplitude and period of variation can arise, which IΒ a characteristic feature only for the space growth conditions. On basic of this analysis, the possible trends of further fundamental investigations on crystal growth of binary alloys in microgravity are discussed. In second part of this work diffusion processes in metal melts has been studied using the tin-lead system and the effect of microcravity conditions on crystallization of specimens after their melting. Experiment was performed according to the ALTAI Soviet Mongolian programm by two cyclograms. Results of metal- lographic and microprobe analysis of specimens, obtained under flight conditions indicate the melt not completely mixed. A qua ntity of eutectic from the tin-side is greater and dendrite;- of superfluous Jl-solution (lead) are less, than near the lead- Bide and some quantity b metestable phase was revealed. On llv specimens, obtained using a second cyclogram four zones were separated ns a result of microprobe analysis. THe microgravity conditions are estimated that affect the efficient diffusion coefficients in the melts under study as well as the structure character!ntics of specimens. The results obtained are then pared wit!) alloys crystallized in unequilibriuni conditions. - 155 - IAF-83-I59 X-RAY ANALYSIS OF THE CRYSTAL STRUCTURE AND THERMAL EXPANSION OP THE JNTERMBTALLIC COMPOUND (Tbnn Gdn 0),Co . . CRYSTALLISED IN SPACE u#ti 0#z 3 E.M.Savitsky, R.S.Torohinova, A.S.Ilushin A.A.Nikolaev, I.A.Nikanorova A.A.Baikov Institute of Metallurgy of the AN SSSR, Moscow State University, Moscow, USSR The polyorystal samples of the intermetallio compound (Tbn QGdn o)^Co have been crystallized on Earth and on b u#Cf u'd -'board the orbital complex MSalyut-6" in micro- gravity conditions under identical thermal conditions* The crystal structure, phase composition and thermal expansion of the ground-based and flight samples have been investigated by X-ray diffraotion technique in the 5-3OOR temperature range* It was established that both samples are single phase and isostructural with GdJ3o compound (orthoromb., space group Pnma). The anomalies have been found on the tempera- ture dependences of the lattice parameters, atomic volumes of the ground-based and flight samples* The comparison of the thermal expansion data with magnetic measurements data revealed magnetic nature of these anomalies connected with magnetic phaseous transitions. The analysis of the shape, resolution and halfwiths of the diffraction peaks of the X-ray spectra of the samples crystallised on Earth and in spaoe has shown that the per- fection of the orystal structure of the flight sample was sufficiently higher than that of the ground-based sample* - 156 -

TAF-03-I60

INFLUENCE OF MlCIiOGHAVITY ON TUB ChYaTAI.M7AT.UM OF THE METALLIC MATLH1AI3

V.NoPimenov, V.N.Kubasov, L.i.lvanov A.A.Baikov Metallurgical Institute of the Academy of Uoiences of the US.HH

The bulk crystallization of the molten nulutiona of the W-Al and Cu-Al systems have been "tudi*»d in both lg (on-ground) and low-gravity space experiments. The space experiments have been performed on hoard the orbital comp- lex "Salyut-Soyue". The "Splav-OI" (Alley~01) furnaoe have been used ID both oases. It was established that during solldifloation of the solution In molten Al, the tungsten-aluminium oryotale of the WAI A And WA]~ compounds In the ground-baaed samples and WAle only In the flight eamples were formed. The cry* tale growth ID low~g environment are muoh more uniformly distributed In the matrix, have larger sl?.ee and are more perfectly faoeted compared to the ground-based orystalfl. These results show that in the flight experiments (in the absence of I-g convection In liquid) the rate of mioiaetl on decreases and the rate of crystal growth tnoreanes. Investigation of the Al-Cu samples shows that the struoture of the solidified A]-5* Cu Ingots consists of <* .-solution grains and («;»•! solution + 8 -phase) eutfotloA . The oc.,-solution gfftlns In the flight 3amj>1 e* are more homogeneous compared to the ground-based ones: the Cu-concentratlon Iβ of 2-3 «t*ft In the eero-g Ingot while It varies from 2 to 4 wt.H in the ground-based The structure of the Al-OO* Cu aamplee aonslets of the ex. ..-dendrites and eutootlos. Dendrites grown In a loww-gg environment have significantlgj j largeg r elees. In s of tthhe elong-Ronoentratiolti n Alonl g tthhe maiin axiis (fro(f m 4.54 - -5.0* up to 3.0-3.7% from the bottom to the top respective ly) has been found. - 157 - 1AF - 83 - 161 EXPERIMEN1AL STUDY ON ONSET OF OSCILLATORY MARANGONI FLOWS R. MONTI - L.G. NAPOLITANO - G. RU5SO - G. MANNARA Institute of Aerodynamics "U. Nobile", Univ. of Naples (ITALY)

Many experiments on thermal Marangoni flows in floating zones have sy- stematically shown the occurrence of oscillations of the thermofluidy- natnic parameters above a certain value of the Peclet number C'e.,) (so- metimes called Marangoni number) in both micro-g (large scale speci- mens) and one-g (microscale specimens). The experimental evidence has not been backed by theories allowing to provide the criteria for the transition and to predict the influence thereupon of the other parameters (like the g-level, Prandtl number, slenderness ratio, shape factor, thermal boundary conditions and so on). The few data available on the transition conditions and the scat- ter of the critical Peclet number (Pe ) calls for an analysis of the transition mechanism and for a more sistematic study of the influence of the geometrical and ambient parameters on the Pe . This paper presents experimental results obtained with a microscale Silicone Oil floating zone at different Prandtl number. In particular the transition points, from the steady to the oscillating regime and from the oscillating to the steady regime (by visualization of the tra cers in the zone) are correlated with the measured values of the Pec- let number. The overall heat transfer between the two discs is also measured from which the convective heat transfer (Q ) is computed and correlated with the value of the Peclet number; the 0 (Pe) behaviour depends on the flow organization and has been found £o change drastically going from one regime to another. A thermographic system has been employed for the evaluation of the surface temperature of the floating zone; a cor- relation is attempted for correlating the surface temperature distri- bution at the middle point with the first occurrence of the oscillato- ry regime. - 158 -

IAF-83-162 IAF Adstract

EXPERIMENTAL SYSTEM TO PRODUCE ARTIFICIAL FNOW ON THE STS-6

Sigeru Kiinura", Tetsuji Shibata°, Akito Oka°, Ryushi Kuwano? Hiromi Onoc? Riichi Nagura0? Yoshito Narimatsu and Jun Tanii

The idea of producing artificial snow in space was first proposed by two Japanese high school students. This proposal was acted upon by the authors who have developed an Experimental System To Produce Artificial Snow On The STS-6. The Experimental System was flown as one of the net Away Special (GAS) payloads onboard the Space Shuttle "Challenger", On April 7, 1983, the crew onboard the "Challenger" activated the Experimental System and the snow experiment was repeated four times automatically by an internal sequence controller. This was Jpan's first experi ment to be flown onboard the Space Shuttle.

The Experimental System is composed of two identical subsystems. Each subsystem not only grows snow crystals but includes equipment to observe and record the growth process automatically using CCD (charge coupled device) video cameras and video tape recorders.

Get Away Special payloads are required to be self contained, i.e., they do not use any of the Shuttle services, e.g., power, thermal control, sequence of experiments, and do not affect other Shuttle missions. Accordingly, the Experimental System has internal Ni-Cd batteries and for safety purposes an alarm and an automatic power disconnect.

The Experimental System developed has passed vibration tests simulating Shuttle launch conditions and an environ- mental test simulating thermal conditions expected on orbit.

The key technology employed in this Experimental System is two identical cold chambers to make and grow snow crystals The size of each chamber is 40mm x 40mm x 100mm. Two semiconductor cooling modules are attached to each chamber to cool down the inside of the chamber to minus 15 degrees centigrade. Cold chambers were previously available however, they were too large to install in a GAS container and did not allow any observation of the growth process. In addition power consumption was excessive.

Another important problem to overcome was to prevent the water used in the Experimental System from evaporating and/or scattering before the space experiment began. The - 159 -

authors were able to resolve these problems by performing basic experiments on the ground while simulating launch and orbit, environmental condition.';.

In the ground experiment this Experimental System grew starlike hexagonal snow crystals, the diameter of which is about lmm. The main purpose of the space experiment is to investigate the effects of weightlessness in space on the growth of snow crystals.

This paper describes the development, construction and configuration of the Experimental System To Produce Artificial Snow On The Space Shuttle.

o Asahi Shinbun Company, S-3-2, Tsukiji, Chuo-ku Tokyo 104, Japan

oo NEC corporation, 4035, Ikebe-cho, Midori-kn, Yokohama, 226, Japan - 160 -

IAK--163 Tilt. BDUP: A MICROfiRAVITY FLUID SClrNCr I AC II IIV

R. M0N1I - L.G. NAPOI.ITANO

Institute of Aerodynamics "U. Nobile", Univ. of Naples (1IAI.Y)

Ihe BPDUP (Bubble Drops and Particles in liquid matrices Unit.) is a se cond generation Microgravity Fluid Science Facility which is now hpiny considered for an ESA Phase A study. The paper describes its df-sicin phi losophy, its scientific objectives and its design goals. The prescribed design goals are based on the exploitation of the fa*.) experience and on the users requirements (as derived from the pettinient literature and from ESA calls for Experiments). The concept of modularity, is used in tho design philosophy of the Willi' and it is extended to its functions, configuration, operation and pro'ii rement; this will hopefully result in a multi-flight, continuously it" proving, multi-goals Facility likely to be extensively used by the s( ie» tific community. The Scientific objectives are grouped into two classes which -eftr !o a first level (for immediate inip1enientation)and to a second level (fo» a gradual subsequent implementation). The first level objectives allow the experimental studies of: - Dynamics of intrusions (bubbles, drops, solid particles) in liquid matrices. - Dynamics of Solidification Fronts - Interaction between intrusions and solidification Fronts. The second level objectives concern the fluidynamic study of: - levitated samples - solution growth - life science experiuipnts - eletrophoresis The BDUP is basically made up by a number of Modules which include (huth at level 1 and 2): a) Service Module, providing the stimuli, diagnostics, controls and da ta acquisition, preelaboration and display b) Test Modules, for each class of experiments c) Ancillary Modules, for the preparation of the experiments d) Optional Modules, for a more accurate and/or for an interactive ex periment conduct. Diagnostic systems, which are being considered in parallel ESA's studie are described together with a number of suggestions for creatinq, positi-i riing gaseous, liauid and solid intrusions in a liquid matrix and tor 1 hi- '» subsequent dynamic studies. - 161 -

IAF-83-164 DATA MANAGEMENT SCHEME FOR JAPANESE EXPERIMENTS OF FMPT Shoji TANAKA, Katsuo YONEZAWA National Space Development Agency of Japan

An example of data handling system for accommodating a number of experiments to Space Shuttle/Spacelab is presented. NASDA( National Space Development Agency of Japan ) plans to conduct a varied group of experiments( about 30 themes ) accommodated to Space Shuttle/Spacelab to be launched early in 1988. This project is called FMPT( First Material Processing Test ). The experiments, to be carried out in thf> Spacelab experiment segment, range from those of material processing to life science. The experiment equipments to be used are;( 1 ) for material processing, the acoustic levitation furnace( ALF ), the continuous heating furnace( CHF ), the gradient heating furnace ( GHF ), the image furnace ( IMF ) and the large isothermal furnace( LIF ), ( 2 ) for life science, the electro-phoresis unit, the thermoelectric incubator( TE incubator ) and the phisiological monitoring system( PMS ) In addition to these, several special purpose experi- ment equipments are being developed. As the number of experiments is comparatively large, if experiment equipments are interfaced with the RAU ( Remote Acquisition Unit ) individually, various kinds of interfacing equipments are required, resulting a rather complicated configuration. And cost and time required for the design rise up, maintainability and operatio- nability of the system fall down. Hence to design such a system, a systematical approach is indispensable so as to realize a proper interfacing with the CDMS( Command and Data Management Subsystem ) of Spacelab and to facili- tate distribution of the resultant data. Taking cost, operationability and maintainability into main consider- ation, ( 1 ) interfacing way with the CDMS, ( 2 ) control and operation scheme and ( 3 ) utilization of common usage facilities are discussed. As for interfacing way with the CDMS, through a trade-off study, the SPSME( Spacelab Payload Standard Modular Electronics, developed by NASA ) has been selected The SPSME consists of common usage modules and functio- nal modules. Common usage modules have been developed by NASA. Functional modules peculiar to FMPT are under development by NASDA. Included are the SI0{ Serial Input/ Output ), the BSI( Biievel Signal Input gate ), the BSO ( Bilevel Signal Output register ) and the VTRI( Video Tape Recorder Interface ). The SIO controls bidirectional - 162 -

binaiy ildld at a rate of 20 Kbps. The MH1 has 48 (.-haitne! I for inputting the bilevel signal. The BSO has 4H clwuinfi« for outputting the bilevel signal. And the VTRI inter- faces between the SPSME and the DRVTH ( Data Recoidinq Video Tape Recorder ), which is an element of the DTiVH ( Data Recording Video System ). The distributed control scheme has been adapted t.<> allow for flexible control and operation of Hie system. An experiment requiring a complicated processing, shall contain a microprocessor, operating with a few commands sent from the SPSME. The flow of commands is from the EC ( Experiment Computer ) to the experiment equipment viri the SPSME. Most of the experiment equipments are desi'in*" to be controlled both in a programmed manner and in a manual manner. As a common usage facility, the DRVS is now being developed by NASDA. It is designed based on the existing VTR for commercial use with a modification to record/ reproduce the binary data. It records image, voice and data, synchronously. The format of video signal confomiu to the NTSC. The two recording tracks are allotted f"t recording voice signal. The maximum data rate is 39. <1 Kbps. And its error rate does not exceed lOK(-fi). Th* Beta type video tape is used. Consequently conventional VTR and data recorder will be replaced by the DRVS, resuI ting a simple and cost-effective configuration. In addi tion, as the resultant data is supplied in the form of standard video cassette tape( Beta type )t the principal investigators will be able to reproduce the video, voir^ and data( a simple interfacing equipment is required ) speedingly and easily. As a result, post fliqht analyses will be much smoother. Finally, through a feasibility study, the draft con figuration of FMPT data handling system is presented! mainly made up of two SPSMEs, two DRVSs and i control units. - 163 -

IAF-83-165

AUTONOMOUS FLUID PHYSICS MODULE (AFPM)> STATUS MID PERSPECTIVES

S. LlOy t V. DEFIMPCI AERJTALIA - Space Sector Turin, Italy

The first Spacelab mission foresees inside the module, mounted on the MSDR (Material Science Double Keck), a payload named fluid physics module (FPM) dedicated to the fluid studies in low gravity environment.

The European Space Agency (ESA) proposes to develop new studies in its microgravity program under the suggestion of and centre of research.

A deep study has just been performed to identify an optimized FPM module, the improved fluid physics module (IFPM). This new payload, on the basis of experience acquired from the pre-vious unit, gives a new visualizing/Illuminating system and a usefult control system for experiment requirements. However the IFPM •JOP« lift work independently during the mission, it is connected with other module*; to a single unit interfacing with spacelab rack. This missing autonomy of power and data transmission means the IFPM larks the necessary flexibility requested by the principal Investigators.

The AEPITALIA Space Sector, under ESA contract, l«s pi imp contractor for a study on the automatization of a fluid phy*ics» module (AFPM).

The AERITALIA Space Sector and its sub-rontractors, "AEHITALIK Gruppo Sisteml Avionicl ed Equipagglament!" ami Techno-Systun Developments is carying out this project In particular AFHITAT.IA for thr technical outline an "Interface Unit" combining with the functional aspects »he scientific return for the users.

The AFPM will be » complex modular system, totally =elf-standing and able to tonyly with tho various needs of th« n>icT«ar*vity fluid science. Combined optica* mi-thuds for the evaluation of coiu.eiilral Um a»

R Monti - (i.P. Russo Institute of Aerodynamics "U. Na rent liquids is based on the principle that the variation it. f inf m< I i«i»i. can be put in f-vidence with the classical optical method1 u-«-m and direct-shadow methods for (|uantitative analysis, their uso heinq confined to the qualitative description of thp test field. For sake of simplicity in data handling, quantitative results have thu' been almost exclusively obtained using Mach-Zehnder Interfprranetpts win ch have however some inherent disadvantages that prevent their or-e in space applications: they are extremely difficult to set up and are ve»v sensitive to vibrations. More suitable are differential inte? feromMt rs (in particular the reflection plate interferometer) because they arp prattically insensitive to vibrations and easy to set up. In addition this family of interferometers, being a direct derivation of Schlierpn systems, can give, as a by-product, also a Schlieren record and a sha dowgraph of the test field with little mechanical adjustment. A compact system suitable for the use in space, proposed t>y the «sit)u:i- in b previous work, allows to obtain sequentially during the same teU a differential interferograph, a Schlieren record and a shadowgraph hv a simple translation of the reflection plate in any desired direction perpendicular to the optical axis: in this way gradients can be detpt. ted in whatever direction is needed allowing the computation of the whole field starting from a single known point. lor the data elaboration, once the interferograph has been fringe shifts are usually counted on an enlarged copy of th>- phic record or, by a , on the film negative, from the fi in ge shift the gradient of the index od refraction is calculated point by point. This procedure is quite tedious and time consuming if a single interfe rogram has to be examined, as in the case of a steady state phenomenon, and becomes almost inpraticable if a whole series of interferograms has to be examined as for the case of a non-steady phenomenon. Automatic data handling and computation is needed in this case. A proposed way is the use of a TV camera instead of a photographic camera to store continuosly on a videotape the images obtained with the optical method. The stored data can be subsequently retrieved and the images examined to evaluate the light intensity distribution. Via an A/D converter the data are transferred to a microcomputer which can calculate by i^ tegration the distribution of the index of refraction and hence of tem perature and/or concentration. This methodology is necessary to ensure the extraction of all pertinent parameters from the three complementary information stored in the TV pictures of Schlieren,shadowgraph and differential interferogram. Surprisingly Schlieren records, from which very seldom quantitative diS ta have been extracted, seem to be the most promising tool once a com puterized data handling system is adopted. Interferograms can then be used, also manually, to check the results and for calibration of the computerized results. This would be the case of zones of uniform maximum Illumination that could be interpreted erroneously as zones of constant gradient of index of refraction although produced by light rays deviations ranging outsfde the sensitivity of the Schlieren system. The method can be applied to liquid specimens, simulating material pro cessing in a microgravity environment, having the dimensions tipically employed in the F.P.M.. Qualitative informations can be obtained from photographic records and quantitative data from TV record analysis. The preliminary tests show the feasibility of the proposed method. Tem perature and concentration fields have been calculated by integration. Heat and mass fluxes have been directly obtained from the fringe shift measurement. - 166 *.

IAF - 83 - 174 Biological Life Support System by H.-P. Leiseifer and A.I. Skoog Dornier System GmbH D-7990 Friedrichshafen, FRG and A.O. Brouillet Hamilton Standard Windsor Locks, CT 06096, USA

As man extends his time in extraterrestrial activity, a new era of , utilization, and research is deve- loping. It is expected that orbital activities such as satellite servicing and research will become routine. Poten- tial uses for manned space stations include facilities for space astronomy, materials processing, biology research and earth resources research. In these, and other future space station activities, man with his unique mobility, work dexterity and adaptive decision-making capabilities will play an essential role. It is recognized, however, that for ex- tended duration missions in space the practical supply of basic life-supporting ingredients represents a formidable logistics problem. Storage volume and weight of water, oxygen and food in a conventional non-regenerable life support system are directly proportional to the crew size and the length of the space mission. In view of spacecraft payload limitations, this will require that the carbon loop, the third and final part-loop in the life support system, be closed in order to further reduce logistics costs. This will only be practical if advanced life support systems can be developed in which metabolic waste products are regenerated and food is produced. Only a Biological Life Support System (BLSS), which not only satisfies the space station environmental control function requirements, but also closes the food cycle, can meet all the expected requirements. A Biological Life Support System has to be a balanced ecological system, biotechnical in nature and consisting of some combination of human beings, animals, plants and microorganisms integrated with mechanical and physico- chemical hardware. The final BLSS functional requirements for space application can be summarized by: - 167 -

Atmosphere maintenance, - Waste water reclamation, - Solid waste reclamation, and - Food production. Numerous scientific space experiments have been delineated in recent years, the results of" which are applicable support of BLSS concept. To ensure that the efforts expended by various international bodies aim toward a common goal, the coordination with existing Spacelab and Shuttle utilization programmes is of major importance in order to avoid dupli- cations and to gain access to valuable data as early as poss ible. Dornier System and Hamilton Standard has in recent years under taken a cooperative effort to define requirements and concepts and to analyse the feasibility of BISS for space applications. Assessing the required ECLS functions (oxygen supply, («„ n> moval, food production and water reclamation) for a BlSS indicates that the food production requirement is the. desiqn driver for higher plants. A system sized for food product i'i»i will be in the position to handle the other FCI r> f wrif lions without an increase in size. Analyses of the Bl. SS energy-mas', relation have been performed, and the possibilities to influence it in order to achieve advantages for the BISS compared wilh physico-chemical systems have beon determined. The major technological problem areas which need immediate attention are: - micro-gravity effects (on e.g. cultivation and harvest inn methods) - cosmic radiation effects, - use of PAR-radiation and HZt protection, and - monitoring and control (including sensor techmOnqy). For the technolgical realization a programme t m the H*>ve I of BLSS has been proposed. THE PERSPECTIVES OF THE USE OP THE UNICELLULAR ALGAE PROTEIN IN BIOLOGICAL LIFE! SUPPORT SYSTEMS A.A.Antonyan, I.A.Abakumova, G.I.Melcshko, T.F.Vlasova Institute of Biomedical Problems, Moscow, USSR The problems of human food supply within the life sup- port system based on the biological circulation of mat- ters is closely linked with the species composition of the system. There are great difficulties in composing a balanced ratio in modelled systems with a small number of species and limited content or complete absence of hete- rotropic organisms. These conditions cause deficiency in full value protein. For several years we have studied the quantaty and aminoacid composition as well as biological value of pro- teins of some algae of various taxonomic groups: Chlorei- la, Chlamidomonas, Euglena, Spirulina. All studied algae are rich in protein. The Spirulina biomass contains the maximal amount of protein (up to 65% of the dry weight), and the cells of Chlamidomonas - minimal (3756). The amo- unt of protein in the cells of algae can be regulated by changing the conditions of cultivation which gives oppor- tunity to balance ratio without changing the cpecies com- position of the system. Proteina of the unicellular alga*» are rich in aminoacida, their amount varying from 36% of the dry weight of Chlamidomonas to 51% of the dry weight of Spirulina. The significant part of them constitute ir- replaceble aminoacids in which the higher plants are usu- ally deficient. The comparative analysis of the amonoacids in the studied proteins of the unicellular algae allows to stake that the proteins of Euglena and Spirulina are characte- rized by the most complete set of aminoecids and a high aminoacid number. The investigations in the experiments on animals also revealed that proteins of these algae have the highest biological value. Introduction of such algae ae Euglena and Spirulina into the biological life support system will permit to provide human food with a significant part of protein. - lb 9 - JAK-UJ-T76 PHYSIOLOGO-HYGIENIC PROBLEMS OP ANIMAL STUDIES IN SPACE PLIGHT E.A. Ilyin, V.I. Korolkov, L.V. Serova, G.N.Pliskovskaya, V.I. Mllyavsky, V.H. Knyazev Institute of Biomedical Problems, Moscow, USSR An Important requirement for animal studies in space flight is to maintain environmental conditions which pro- duce no effect on the animal body. The physiologo-hygie- nic requirements of the life support of animals (rats and monkeys) flown on unmanned bioaatellites were deve- loped, using data on animal biology, biometry, metabo- lism, tolerance to unfavourable flight effects (accele- ration, elevated temperature, etc.). These requirements for the life support system were used to manufacture sys- tems which provide free and fixed maintenance, removal of urine and feces from the inhabited area, food and water supply, air regeneration, conditioning and decontamina- tion* The above pbysiologo-hygienic requirements acquire particular importance as applied to animal studies onbo- ard manned spacecraft and space stations where specially trained personnel will take an active part in animal stu- dies. It follows from our experimentation work that in manned + animal flights the most important problem of compatibility is that of zoo- and anthropotoxins as well as microorganisms. - 170-

IAP-UJ-I77 HYGIENIC ASPECTS OP HABITABILITY IN THE EXTENDED SPACE MISSIONS S.N. Zaloguyev, Yu.P. Bizin, V.P, Savina, A.N. Viktorov Institute of Biomedical Problems, Moscow, USSR As the duration of the space missions is increased and the scientific and technological tasks encountered by the crew members become more difficult, the hygienic aspects of habitability are assumed a great importance. Among hygienic aspects of habitability as related to the extended space flights, of practical significance are the maintenance of gas composition and other parameters of cabin environment, sanitary-and-bacterlological state of a habitable environment, personal hygiene, sanitary and household support, and the food and water supply to a cosmonaut. The studies performed in the extended space flights of the orbital stations Salyut-6 and Salyut-7 made it possi- ble to obtain data and to improve our understanding of the basic physiological and hygienic aspects of habitabi- lity. During the flights of these stations the environmental parameters, atmospheric gas composition, microbiological indices of a cabin environment and automicroflora of the crew members have been studied. The more effective measu- res of personal hygiene and hygienic procedures have been tested during the flight. The data obtained enable one not only to evaluate the state of many links of the life support systems but to map out the measures of a further improvement and opti- mization of cabin environment during extended space flights. - 171 -

IAF-83-178 SCIENTIFIC ]JTIJLI^ATION Of BIORACK D.A.M. Mesland turopean Space Agency Since the architecture of living orcianisms can be considered to reflect the result of an evolution that is triggered by mutations and ever changing environmental constraints, the effect of the earth's gravity must be expected to be tightly woven into both its structure and its functions. Imposed microgravity will therefore probably influence not only steady state biological mechanisms, but especially those biolo- gical systems during the process of acquiring new, programmed forms or functions, i.e. differentiating cells and developing organisms. The study of such influences will shed more light onto mechanisms which have developed in living systems on earth which 1) counteract the effect of gravity, and 2) organize cells and organisms due to the ever present gravity vector. The BIORACK, presently in development by ESA, offers the opportunity to meet the above scientific objectives. It is a reusable, multi-user facility, built into a standard Spacelab equipment rack and to be flown on typical Snacelab missions. The main hardware constituents of this facility are two incubators, a glovebox and a freezer/cooler unit. The biological specimens and user developed hardware can be housed in two types of standard containers, type I with a volume of 50 ml and type II with a volume of 300 ml. Approximately eighty such containers can be flown with BIORACK. One incubator operates at a set temperature in the range of 18-30°C and the other in the range 3O-4O°C. Both incubators have racks to hold the standard containers as well as centrifuges to simulate *l-g in orbit which allows for discrimination between effects of microgravity and other effects of space flight (radiation, vibration, environment). Only the small type I standard container can be mounted on a centrifuge. The glovebox has the features of a safety cabinet and maintains a cleanliness level of about class 100 in the working area. It permits the handling of biological specimens without the risk of contamination and the safe exchange of gas and fluids, including toxic material such as fixatives. Facilities for microscopy, photography and cinematoqranhy are also planned for the glovebox system. The cooler and freezer, combined in a single unit, nrovide low tempera- ture environments for pre-experiment and post-experiment storaqe purposes. These features make the BIORACK facility suitable for research on small biological objects such as small nlants, insects, single cells and bacteria. Fourteen experiments from five different countries have been selects! by ESA and will be flown in the HIORACK on the German D-l Spacelab mission. The total of scientific research areas covered bv - 172 -

IAI--H3-I78 -• page 2

experiments and the biological specimens used fully exploit the potential capabilities of the BIORACK system. Since research on gravity effects in small bioloqii.al organisms has only recently started some experiments have a rather speculative character. They are based on theoretical considerations likp an expected different behaviour of the plasma membrane-piotein system (experiments with bacteria and with plasma cells), or an expp or from clinostat simulations. A further set of experiments, designed to test a elaborate scientific hypothesis, use systems in which gravity is known to be involved, e.g. fertilization and early development of Xenopus eggs and the function of amyloplasts in the statocytes of Lentil seedlings. A different type of experiment which will also be carried out in thp BIORACK addresses the question of the origin of circadian rhythms (experiment with Chlamydomonas). Detailed descriptions of the experiments will be given. Although it is premature to address the scientific results likely to be obtained, a few aspects associated with the BIORACK philosophy may be mentioned that provide the required conditions to acquire unambi- quous data: 1) Controlled temperature conditions are provided from the time of preparation of samples on the ground shortly before launch, through the flight operations phase until return of the sample to the ground laboratory; 2) All relevant environmental parameters will be monitored during the mission; 3) All experiments include 1-g controls to be performed in flight under similar conditions, allowing to discriminate between effects of gravity and other effects; 4) All experiments will be duplicated in a second BIORACK model situated at the launch site and in near-synchronism to the flight experiments; this control aims to discriminate centrifuge gravity simulation from other unknown effects. This concept has been devised to ensure that all scientific results can, with the highest possible accuracy, be attributed to the appropriate flight-dependent factor. The comfortable overlap of different areas of investigation in the selected experimental package constitutes another significant condition for fruitful cross evaluation of the results to be obtained. - 173 -

CtiD VIWUAI. .STIMULATION W.\I\CK H:;iN

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MODERN METHOD AND INSTRUMENT FOK MEASIUMMO rsxHK' PKRPORMANCK

il.Hidey, I'.Reines, I..Bognar, M . Atju.st • m , Z . t'.

Intet cosmos Council of the Iliinqai i rtn Acnlem- of fir i eoci.'S

1369 Budapest S P.d.B. i i r> Mungaiy

Tlieo rjv: Flying performed on modem a i i cr af Ueclm ii)u<- i in poses quite a Herculean task and psychic load on piln*':. Piloting of an aircraft, observations during the infli-it-. period need processing of information flow in nui-h a pi • • portion that it reaches or can exceed the limits of m^n' peak performance duriny some period of flight. The latent, impairments appearing in psychic fnn< fion can considerably influence the success* flight pxfi i< (:1on and they can endanger the safety of flight. In the course of last 1O yeat s wo have de"ot«<) quite a lot energy to elaborate such ccitinct , obied i "< methods that, provide detection of these latent irupaif ments in due course, moreover to work out a such method that provides prognosis of pilot's psychi?: performance As a result of this work came to life the device thai h-i been used successfully by the Soviet, Hungarian, Monqi 1i an, Roumanian cosmonauts onboard the orbitil complex "Salyut-Soyuz".

According to their method in the case of lneasui ing four-choice reaction time, the phase character!si i< of cortical activity can be strained out of the complvx activity series ranging from sensation as far as react io that measuring of four-choice reaction time has been completed by measuring sensory-motor reaction time, con- sequently the method is confinable from the devices mea suring sensory-motor reaction time and informations PHI formed by them, but it is confinable from the measui ir.gn of different four-choice reaction time. Measuring of fmn -choice reaction time must be modified so, that strictly the same quantity of informations must be conveyed dm in the examination period. The information theory measuring oi four-choi< •> reaction time can be considered as a deformed data trans mission event and its "channel" parameters can be delei mined by the methods used in telecommunication. So *li^

^ J quantity of cortical Information processing can be given in bits, while speed of information processing can be given In bit/sec. In this way the information processing ability - characterising the psychic performance welL - can bo denoted in algebraical expression.

Conclusion; We have stated that the extent of psychophysiologi- cal reserves can be evaluated on the basis of change in in- formation processing ability - caused by stress - and some of the important indices of emotional endurance /pulse rate, galvanic skin resistance/. In the case of adequate psycho- physiological reserves the operator can preserve his in- formation processing ability - or the decrease is insigni- ficant - even in coplicated situation. 1. By the objective method, two aspects of pilot activity were examined: the actual activity of cortex as mental work capacity and emotional tension. 2. The method is suitable to evaluate psychophysiological reserves and prognostication of pilot's working capacity. 3. The experiments prove that psychophysiological reserves are needed to the pilot's safety activity. The permanent training and experinces have a great role in preserving or decreasing the reserves. 4. The time honoured method and device is excellently suit- able to measure the psychic state of space station per- sonnel, to prognosticate the psychic activity as it has already been performed together with our Soviet col- leagues in 1982 on the IAF Congress held in Paris. - 176 -

lAl'-B 1-!H:'

MEW ADVANCKl) TL!) SYKTKM PUP ili'M.T. ho<; [ Ml.TI-Y

I. Feher, B. Hzdbo, •). Vagvolgyi, !:. \h-m>-, P.P. :-zdW>, A. CHOI'P

Central Research Institute for1 Phy:j \i:u uf Hit- Hu nj'.-.t r- i •«11 Academy of Sciences, Budapest, P.O. P. 49,Hungary , II-I!.?1.

A new version of the Pi lie Tl.l) reader, t lie MA^"i,, IMS recently been developed for1 space applications. Tli" <'irlii-,\. to increase the sensitivity and to decrease th<.> OVCIM 11 n-ri and have led to a more versatile TLD system, the NA'.Mifi, which can be used not only in space applications but. also for environmental monitoring, or even in accident do« im<-t r-\ • New bulbs have been developed with the two pint; on Mi>' same side of the glass tube. The tube is of low potassium content glass /so the self-dose from K is low, winch i;; important when one intends to measure dosef.: nt low do:,e rates/, and the vacuum is inside the tube, therefore I liopni-i I dissipation is small. The limit of the linear dose tango of these bulbs is above 10 Gy, beyond which correction mur.t !>>• applied because of the supralinearity. All bulbs liavo a single pen-like holder enabling them to be read out in tli^ MA206 reader; all bulbs can now be changed in the holder. The measuring range extends from 1 iiGy up to 10 G%',i-'' three orders of magnitude greater than it was earlier. Tic measured dose value is shown on a four digit display with automatic; range r>witch. An electronic circuit protects t ?•-•• device from damage due to mishandling. The HA70G reader ^a\> be operated on the ?7 V battery of the space station- Another new variant is the NA7O6E which has been d^v>3toped for1 environmental dosimetry; this is equipped with a balt^ry and can be operated alone, on a car-battery, or from th^ ma i ris .

j - 177 -

1AF - Hi - Ifc.J Study and Development Activities of Dornier System on Space B iology/Med i t ine I qu ipiiMMit and Pay loads for Spa*. Hah and F reef lying Platform Appliration

Hansgeorej W.K. Francois, P. SIIIIIIPI DORNJHt SYbTIM GMBH Space Programme Me partmen I Friedrichsha fen, W. Or many

Since the days when Europe entered into the Manned Spaiefliuht and Dornier System was awarded the contract for the develop inent of Environmental Control and life Snppot 1 System {1 r I s> for Spacelab, we always committed ourselves to HPW prohlpins and tasks in the field of Life Sciences in Sp.T« o I so on payload element and equipment level. In particular we studied the feasibilities of life SΓ i e payload elements, as: o BIORACK, a spacelab single rack to be equipped with - two incubators which can be set at two different of controlled temperatures - a freezer/cooler combination unit - a glove box for Cell and Molecular Biology research o Botany Rack, a single spacelab rack equipped with Hn>aiuiol Standard Equipment for Botany research o B10CHAMBER, as an autonomous Life Sciencp PayloaH fur anln matic long duration experimentation of different liwinn samples on a freeflying platform, p.tj. on FWUiA. Dornier System is now workinp on: o the feasibility of an 1-g control centrifuge o the design (Phase B 2) of the fnlinwinq equipment fin BIORACK: - 1-g reference centrifuge - experiment containers ({.ype I, type II) - passive thermal conditioning units - 178 -

o the design of two German Experiments for BIORACK: - daily rhythm of clamydomonas - differentiation of B. subtilis o a study (Phase A) on the Botany Facility as a part of the a.m. BIOCHAMBER for experiments on plants and spores o a study on an ANTHRORACK as a Multiuser Facility on board Spacelab for Human Physiology research, a spacelab double rack to be equipped with: - service elements - different, mission dependent experiment packages for different scientific mission objectives, as: - cardiovascular - biochemical-hormonal - sensori-motor This paper shall give a short overview about the Dornier Sy activities in the field of Space Biology and Medicine by short discussion of each a.m. item. - 179 - IAF-83-184 The Frog-Statolith-Experimenb (STATEX) of the German Spacelab Mission Dl - Scientific Background and Technical Description

J. Neubert, W. Briegleb and A. Schatz DFVLR, Institut fur Flugmedizin, Postfach 90 60 58 Linder Hone, 5000 Koln 90, FRG

Frog embryos and tadpoles of Rana Tempotaria grown undei conditions of simulated weightlessness on the Cast-rotating clinostat showed some unusual behavior patterns during and after the simulation period. The favored attitude of the embryos during the simulation period is almost perpendicular to the axis of rotation. After emerging the tadpoles try to orient themselves in the direction of the rotor axis. After entering normal gravity they have difficulties to orientate themselves - they swim in typical loops. The adaptation time depends on the duration of weightlessness simulation.

These observations implied microscopic and electron- microscopic studies of the gravity sensing system (macula utriculi, macula sacculi, and otolith membranes) of the vestibular organ to demonstrate if there are morphologic reasons for this behavior. Light-microscopic investigations of different stages of development showed no differences between control animals and those developed in simulated o-q.

With the help of electronmicroscopic investigations, however, it could be shown that extended exposure to Simula - ted weightlessness is followed by significant alterations i<. the sensory epithelia. Large vacuoles, filled with necro- biotic fragments of cell organelles (ER, Mitochondria) were concentrated in the region where an otolith membrane covers the sensory cells but were mostly absent in zones of the epithelia with undifferentiated cells. To prove if these alterations are reversible in lg, tissues of animals grown in 0-g simulation and thereafter adapted to )g were investi- gated by electronmicroscopy.

No fundamental differences in the microstructure of sensory epithelia tissues between these and normally developed stages could be found. The vacuolization has dramatically diminished and has become insignificant. This result demon- strates the ability of the tadpole organism to regenerate malformations of the gravity sensing system. - 180 -

These findings ate the scientific background of an nx ment to be flown onboard the Spacelab Mission Dl. Th*> p describes the different components of the facility and special function within the different mission phases, n discusses the difficulties of reconceiling the ^rrient if iV goals of the experiment with the limited electric powei and crewtime; so the experiment facility was planned as an auto- nomous one; to reduce the electric power requirement-** wir,p special techniques are used.

The experiment strategy from ground activities befoip launch over the mission time-line until to the final scientific exploitation of the biological specimen in the experimenters laboratory and their schedule are described. Finally it will be stated, that the technical lay-out of the STATEX ha< rlvar <> has been developed as a multi-user facility usable also fur other biological experiments without costeffect i *»e !-ba;ici«>^ in the design, and that also a interdisciplinary use m.-iy l>^ possible. - 101 -

SINGLE CELL ALGAE AND HIGHER PLAHT CiSLI. CULTURES USIHG IN SPACE BIOLOGY Sidorenko P.G., Popova A.P., Klimchuk D.A., Martyn G.M., Ivanenko G.F* N.G.Kholodny Institute or Botany, Ukr.SSR Academy of Sciences, Kiev, USSR Single cell algae and higher plant cell and tissue cultures are the perspective objects in the space biolo- gical research. They may have a great practical impor- tance as the components of a closed ecological system which are the regenerants of an air medium and the nut- rients sources* Results obtained in the space experiments of short duration on the HSoyuz-22" and the scientific orbital station "Salyut-6" with autotrophic strain of Chlorella and higher plant cell culture Haplopappus showed no de- viation in cell structure and their functional activity under orbital apace-flight conditions* In model experiments under vibration and acceleration effect under conditions of spaceship going into orbit no prominent were found in growth, structural organization and functional peculiarities of cells, though some short-time deviations were defected such as the changes in nuclei sizes, the rearrangement of submicroscopic mitochondria organization and of the structure of a pro- tein-synthesizing apparatus* Data are obtained about the normal growth under photo- culture conditions of higher plant cells in vitro inclu- ding those of food plants. The studies results permit stating a high resistance of cultured cells of algae end higher plants to space- flight factors, their high adaptability to cultivation under different trophic conditions* This opens wide pro- spects for using such cells as models and objects on life-support systems. - 102 - IAF-83-186 RESPECTIVE ROLES OF MICROGRAVITY AND COSMIC KAYS n|» PARAMECIUM TETRAURELIA CULTIVATED ABOARD SALIUT 6

H. PLANEL, R. TIXADOR, G. RICHOILLEY and G. GASSMT Iiaboratoire de Blologle Midicale, Faculte do M&< TOULOUSE France

In order to demonstrate a possible effect of q on cell, cultures of a single cell organism, Paramecium tetraurella, we investigated aboard the Soviet spare Stat i

These modifications are note related to the space flight dynamic factors : cells were kept at a low tempeiati' re and were in dormant stage during the launch. They wet*1 not due also to an indirect effect of gravity, i.e., to a change in distribution gradient of nutrients or wastes in the culture media : indeed, in cultures performed on far Hi in roller tube, the growth rate remained normal.

These notions suggest that results of CYTOS expeii ments could be explained by a direct effect of mierogravity or cosmic rays on cells. In order to determine the resppet i ve roles of these two factors, an additionnal experiment was carried out in .balloon flight, using the technology previously developped for the space experiments.

The transmediterranean flight, 22 hour long, result*"] in a stimulating effect on cell proliferation, similar to this observed in cultures of the space experiments. Howevoi. cell volumes and ionic concentrations were quite normal. This results demonstrate that changes in cell proliferation kinetics are due to exposure to cosmic rays and this conclu sion is in good agreement with previous works,carried out on earth, on the effects of very low doses of ionizing ra- diation {PLANEL et al. 1965 - PLANEL et al. 1976). Further- more, changes in cell volume or electrolytes apppan to hp related to microgravity. - 185 -

The discrepancy of our results and those reported by several authors (MONTGOMERY et al. 1978 - SOUCHKOV and ROUDNEVA, 1979) can be explained by the biological material used in these experiments : adherent cells on solid support or, in our experiments, free swinunting cells. Gravity effects and, in consequence, microqra- vity effects should be different. IAF-83-187 RESULTS OF SPACE EXPERIMENT PROGRAM "INTERFERON"

M.Wlae1, L.Batkai1, I.Stager1, K.Nagy1, l.Hlros2, •2 3 I* I.Konstantinova , M.Rykova , I.Mozgovaya , O.Guseva , V.Kozharinov*.

Microbiological Research Group of the Nationa] Insti- o tute of Hygiene,Budapest; Medicor Works, Budapest, and ^Institute of Medico-biological Problems, Moscow.

A space experiment program named "Interferon" was elaborated within the frames of the international scien- tific cooperation "Intercosmos". This program was car- ried out during the spaceflight of the Hungarian-Soviet cosmonaut team (1980.May 26-June 3.) and repeated during the flight of the Roumanian-Soviet crew (1981.Hay 16-22). In experiment "Interferon I" the effect of complex conditions of spaceflight on interferon production "in vitro11 by human lymphocytes isolated from healthy donors was investigated using a special equipment. Assay of antiviral activity of flight and ground- control samples of experiment "Interferon I" showed the!; in every tube where inducer was added interferon pro- duction could be demonstrated. Interferon titers of the flight samples were 4-8 times higher than those of con- trols, independently of the Inducer used (poly IsC, poly G:C, gossipol, PPD and UV-NDV). In experiment "Interferon IIn the influence of space- flight on the biological activity of human interferon preparations and interferon inducers was studied. No difference between the antiviral activity levels of flight and of ground control samples of human inter- - 185-

feron preparations was observed when the preparations were kept at 20°C for seven days. Interferon inducers (poly I:C, poly G:C, and gossipol) placed in space laboratory for 7 days maintained their in- terferon-inducing capacity. In experiment "Interferon III" the interferon produc- ing capacity and natural killer activity of blood lympho- cytes of cosmonauts before and after spaceflight was in- vest 1 gated. A lower interferon-producing capacity and natural kil- ler actirity of lymphocytes of two cosmonauts was observed in the first week after landing. - 186 -

IAF-83-188 SEROTONIN IN INDIVIDUAL HYPOTHALAMIC NUCLEI OF RATS AFTKN SPACE FLIGHT ON BIOSATELLITE COSMOS 1129 _ * * Culntan J.t Kvetnansky R., Serova L. , Tigranjan R.h^, Macho L7 Institute of Experimental Endocrinology, Centre o{ Physio- logical Sciences, Bratislava, Czechoslovakia and TnsHlu- te of Biomedical Problems, Moscow, USSR. The aim of this study was to evaluate the influence uf stressful factors and of the state of weightlessness dur- ing long-term space flight on the activity of serotoninor• gic system in rat hypothalamus. The experiment on Cosmos 1129 was based on our previous results obtained in rats exposed to single or repeated restrain stress in the laboratory. Our previous results have convincingly demonstrated a significant increase of serotonin concentration /5-HT/ in the hypothalamus in acu tely stressed rats. This response, which was found also in the isolated hypothalamic nuclei, was diminished in repea tedly /4O-times/ immobilized rats. From these results it could be argued that if rats were chronically exposed tr> intensive stressors during space flight, after their return to Earth, they should react to immobilization st.tess by similar manner as chronically stressed rats. If however, space flight would not be connected with prolonged inten- sive stressful stimulation of brain serotoninergic system, then the rats should react to immobilization stress as the animals acutely exposed to stress. Male Wistar rats of specific pathogen free colony weig- hing 250 - 3OO g were used. The animals were divided into 3 groups: 1) subjected to space flight /group F/ which spent 18.5 days aboard biosatellite Cosmos 1129 under the state of weightlessness, 2) synchronous group /group S/ which was exposed to the same conditions on Earth as group F in space, except the state of weightlessness, 3) intact controls /group C/. All groups were further divided into 3 subgroups; a) sacrificed 7-10 hours after landing, b) sacrificed 6 days after landing, c) subjected to 15O min of immobilization stress daily for 5 days after land- ing and killed immediatelly after the last exposure. Immediatelly after decapitation the whole brains were frozen and individual nuclei were isolated from frozen section by means of a special needle. The following hypo- thalamic nuclei were analysed: supraoptic n. /NSO/, para- ventricular n. /NPV/, suprachiasmatic n. /NSC/, perivent- ricular n. /NPE/, arcuate n. /NARC/, median eminence /EM/, ventromedial n. /NVM/, and dorsomedial n. /NDM/. While the concentration of 5-HT was unchanged in the majority of the hypothalamic nuclei of animals subjected - 18? -

to'Cosmic flight, rin iiiiMcasc of thai w,jy. i t-eoi NSo and a decrease if) Nl'l:. Thusi- lindinqb demonst rat*1 th

IAF-83-189 THE EFFECT OF HYPOKINESIA ON. LIPID METABOLISM IN ADIPOSE TISSUE L. Macho, R. Kvetfiansky, M. Fickova Institute of Experimental Endocrinology, Centre of Physio- logical Sciences, Slovak Academy of Sciences, Bratislava, Czechoslovakia

The most important factor affecting the human and animal organism during the cosmic flights is the state of weight- lessness. Several models of hypokinesia were used for simu- lation of the effects of weightlessness and diminished mo- tor activity in human subjects and in experimental animals. Because the less attention has been given to the changes of lipid metabolism during hypokinesia the purpose of the present investigations was to study the effects of hypoki- nesia on lipogenesis and lipolysis in rat adipose tissue. The adult male Wistar rats were immobilized in special plastic cages for various period /I to 60 days/, control groups were kept under standard conditions, 6 animals per cage. After the decapitation of animals, the plasma was u- sed for the determination of nonesterified fatty acids /NEFA/, epinephrine /E/ and norepinephrine /NE/ content. The slices of epididymal fat pads were prepared for estima- tion of the release of NEFA without and after the addition of NE, and for the determination of incorporation of ^C-U- -glucose into lipids after the addition of insulin. Isola- ted adipocytes were prepared for the study of the binding of JH-dihydroalprenolol to specific beta-receptors. The significant decrease of the mass of epididymal fat pads was noted in rats after hypokinesia during 7 to 60 days. The marked increase of NEFA concentration in plasma was observed in rats subjected to hypokinesia for 1 day or longer period. During the period of recovery /7 and ?1 days after the prolonged immobilization, 60 days/ levels of NEFA in plasma were lower than in control groups. The marked increase of fatty acids release from adipose tissue was observed in rats after a short period of hypo- kinesia /I - 7 days/ and also after the prolonged immobili- zation /21 and 60 days/. This increase of lipolytic activi- ty was also found after 7 days of recovery. The augmenta- tion of NEFA concentration in plasma and of the lipolysis in adipose tissue is related to the increase of the level of plasma E and NE observed in the animals during the hy- pokinesia. Plasma E concentration was increased after 7 days of recovery,this is in good agreement with higher ra- te of lipolysis in adipose tissue. - 189 -

The stimulation of lipolysi s by III', war., however, lower in immobilised vnic. During thf? recovery period the stimu- latory effect of catecholamines on lipo "lysis returned to levels observed in control animals. The investigation of the binding characteristic of ''H-dihyilroalprenolol to beta receptors of isolated adipocyte:; showed wigni f'icind d< cre- ase of binding capacity /to 57 %/ and diminished number of beta receptors /to b^ % of control values/ aftnr PJ days of hypokinesia suggesting tfiat the lower response of adi- pose tissue to catecholamines could be atributed to the decrease in number and binding capacity of specific recep- tors in adipocytes membranes. The studies of the processes of lipogenesif? showed a slight increase of incorporation of radiocarbon from glu- cose into triglycerides after prolonged hypokinesia. The stimulation of lipogenesis by insulin was higher in rats immobilized for the period of 60 days. These experiments showed that hypokinesia has an important effect on lipid mobilization, lipogenesis and procerus of hormone regula- tion in adipose tissue. - 190 -

TAP - 83 - 190

CJC'EDLOGIGAL AQI3SC1S OP HIGHER FEJUIT OHTOrrENl&IS UNDER HICROGRAVITY K.fi.Sytnik, E.L.Korclyura, N.A.Belyuvskaya, V.A. E.M.lIedukha, V.A.lhrasenko, V.M.Fomichova Institute of Botany of the Academy of Sciences of the Ukrainian SSR, Kiev, USSR Studies dealing with cell reproduction, differentia- tion and vital activity, i.e. processes underlying growth and development of organisms, plant ones included, ;u-e of essential iraporlance for solving fundamental and applied problems of space biology. It is shown that moi*phogeneeie processea of vegetative and genital organs of higher plants under microgravity Are normal in the ing in for a certain experimental period. The orientation o£ plant or- gans in the absence of geotropism under microgravity is governed by photo- and chemotropisma. Rearrangements in the sfcructural-und-functional organization of a plant coll, of the root meristeme and root cap in particular, are significant. Changes take place in cell reproduction rate, chromatin state, relative electrophoretic mobility of multiple molecular fcirras of dehydrogenases and their amount, activity of Ca -activated ATPu.se, ultra structure of cytoplasmic organelles, frequency of occurrence of ele- ctron-dense globules on monibrane components of cells which are identified as Ca -binding centres. The character of these changes without noticeabl'3 disturbances in mitosis and cytokinesis suggests that the rearrangements in cell metabolism under weightlessness occur within the limits of existing genetic programmes. Biochemical and physiological processea undergo rather essential changes because of the absence of initially strict determination. For a definite period of weightless-* ness effect "the cell functioning provides, on the whole, realization of cytodifferentiation and morphogenesis pro- grammes at the vegetative stage of ontogenesis. An adaptive nature of the rearrangements in the plant cell atruetural- and-functional organization under microgravity is discuss- ed in connection with a possibility for higher plants to puss through all stages of ontogenesis under these conJi~ tions. In the light of the data obtained, determination of critical stages in hormonal regulation of plant growth and development as well as detection of the cell metabolism links which are the most sensitive to the weightlessness effect are primary tasks for a further elucidation of the role of gravity and weightleeaneee in higher plant vital activity with a view of predicting a reliable functioning of an autotrophic link in biological life-eupport syeteiaa. - 191 -

IAP-83-191

THE EFFECT OF IMMOBILIZATION ON TOE BONK OF RATS

Szilagyi, T., Foldes, I.,J?apcsak, H., Gyarmati, J. jr., Szoor, A. Institute of Pathophysiology, Institute of Anatomy, Ins- titute of Physiology, Clinic of Radiology, University Medical School Debrecen, Hungary

It has long been known from clinical observations, that a state of inactivity /as staying long in bed or bone fractures, for example/ leads to the development of osteoporosis. However, it has become recently known, that weightlessness of astronauts leads to osteoporosis, too. Immobilization proved to be a proper experimental model of osteoporosis induced by inactivity. We chose plaster cast to produce immobilization in order to gain data about the pathomechanism of osteoporosis using X-ray densitometrical and morphometrical, histological and calcium-histochemical methods. Fifteen Wistar female rats were used, weighing about 250 g, twelwe of them were anaesthetized by ether and their right hindlimb was immobilized by plaster caet,, Their left hindlimb as well as that of three intact animals vere used as controls. The animals were then killed by bleeding eight weeks after the operation and their femurs and tibiae were excised. Tibiae were used for light microscopic studies. Femurs were X-rayed in pairs. Finished negatives were evaluated applying micro- radioscopic, densitometric and morphometric methods. Remarkable changes were detected in the femoral bones of immobilized extremities. The number and size of spongious trabeculae both proximally and distally in the epimetaphyses were reduced significantly. In the diaphyses the cortical bone was thinner and its density was fainter compared to the control. According to the X-ray morphometry the reduction of mineralized bone substance was quantitatively proved. The thickness of combined compacts, calculated by using their difference shows a loss of 50 per cent of its mass. Measurements at the level of distal metaphysis indicate a significant reduction of the number of trabeculae and along with that the mineral content was reduced. Compared to the control the proximal epiphyseal cartilage of tibia of immobilized rats, moderately - 192 - broadened primarily by the thickness of the maturing hypertrophic zone - according to our histological inves- tigations. Vascularization and the number of cartilagi- nious cores decreased significantly in the metaphysis of plastered extremities, and osteoblasts were hardly detectable. The number of metaphyseal trabeculae is significantly reduced in the bones of immobilized animals, and marrow space is remarkably widened simultaneously, which is filled with morphologically normal cells. Active osteoblasts are not visible in the immobilized bones. All the phenomena observed indicate resorbing acti- vity of bone cells on the ground substance. As a con- sequence there is a formation of fibrotic tissue. Osteo- clasts can be seen in the cortical bone localized sub- periostally. Kossa-reaction carried out in immobilized bones show the reduction of mineralized bone trabeculae in the tibia. Our examinations prove unambiguously that immobili- zation produced by plaster cast the extremity of rats results in psteopenic osteoporosis. The effect is more pronounced in the spongious bone - as it is proved mostly by X-ray method. There is a transformation of the corti- cal structure of bones, that is, there is a partly deve- lopment of primitive bone tissue in the place of laminar structure. All the signs together indicate the adaptati- onal phenomenon in the bone, that is the organism attempt to retain the supporting capability of bones. Several questions can be raised having to do with the osteoporosis development under immobilization. Some beleive a note that retardation of bone function or acceleration of the destruction of the bone can be re- garded as the principal process. KLEIN et al. arrived at the conclusion that an increased resorption results pri- marily in the reduction of bone mass. Several experiments emphasize the significance of the parathyroids. Our his- tological studies showed osteoclast activity as well as . osteocytic osteolysis indicating hyperparathyroid reaction. The role of mechanical components and changes in vascu- larization has an additional aspect, being important from the point of view of pathomechanism: osteoporosis can be attributed the consequence of the insufficient production of the organic matrix in the bone. - 193 -

Ref. Njimber : I.A.P. 83-192 Title : PRELIMINARY RESULTS OF CYTOS 2 EXPERIMENT. 'Name of authors :

- R. TIXADOR, G. RICHOILLEY, G. GASSET, H. PLANELf N. MOATTI, L. LAPCHINE, L. ENJALBERT Groupe de Recherches Biologiques Spatiales, TOULOUSE (France). - S.N. ZALOGUEV, M.P. BRAGINA, A.F. MOROZ, N.G. ANTSIFEROVA, F.M. KIRILOVA. I.M.B.P. Moscow (USSR). I. - INTRODUCTION Various experiments on bacteria behaviour were already per- formed during previous space flights. Different authors have previously reported the results of post flight studies of the antibiotics sensitivity of bacteria. STAEHLE, R. has studied Bacillus subtilis, E. coli, Bacillus mycoidees after Skylab 2 and 4 missions, only a small portion of Ba- cillus subtilis developped on both missions. The inflight colonies exhibited morphology changes and were more sensiti ve to several antibiotics in post-flight testing.

At the occasion of APOLLO-SOYUS Test Project G.R. TAYLOR and S.N. ZALOGUEV recovered specimens of microflora on various parts of the body of the crewmembers. This experimentation, conducted jointly by American and So- viet investigators, shows that the bacteria collected during the flight were more antibiotics resistant than the bacteria collected in the pre-flight and in the post-flight phase. We have performed the experiment CYTOS 2 carried out during the latest manned flight aboard SALYUT 7 by the French spa- tionaute J.L. CHRETIEN (July 1982). Two bacteria species, isolated from the automicroflora of J.L. CHRETIEN, were tested with different antibiotics during the flight. The principal aim of the experiment was to test the antibio- tic sensitivity of bacteria cultivated "in vitro" during the orbital phase of the f.lifht, using the bacterial method of the M.I.C. (Minimal Inhibitory Concentration). - Staphylococcus aureus, with o Oxacillin o Chloramphenicol o Erythromycin - E. coli, with o Colistin o Kanamycin 2. RESULTS

Table 1 reports the results of sensitivity of Staphylococcus aureus during the flight. The M.I.C. was previously esta- blished during the experiment repetitions. Table 2

STAPHYLOCOCCUS AUREUS

Control in flight

OXACILLIN 0.16^9 O.l6/ig

CHLORAMPHENICOL 4 /*9 4 ,.,<»<:<• ^

0.5 ft g O.S /kg

Minimal inhibitory concentration

Table 2 reports the results for E. coll Table 2

E. COLI

Control In flight

COLIETIN HIC > leyke

KIC > 1 β^fcg

Minleel Inhibitory concentration

The increase of the antibiotics resistance is particularly important for E. coli and lower for St. aureus. On the other hand, we have begun electromicroscopy investigations. These studies of morphology are performed on cells develop- Ped in space without antibiotics and that we consider as in flight control cultures. The preliminary results show that Space flight induces, at least, modifications of cellu lar envelopes. - 195-

3. DISCUSSIOll AND CONCLUSIONS Taking In account the results of CYTOS 2 experiment, we think that there exists a relation between the Antibiotic penetration and changes In the structure of the cellular envelope. This effect of Space flight factors on the bac- terial cell seems to concern several germs. To go forward in the understanding of the mechanisms of this phenomenon, it is necessary to have a greater number of biological samples to study the increase of antibiotics resistance, the growth rate of bacterial po- pulations, and to carry out other ultrastructural inves- tigations, particularly to investigate if the modifica- tions of cellular envelope are located on the whole en- velope or on the membrane, or on the cell wall. - 196 - IA' -;jj-iyj MODEL STUDIES OP WEIGHTLESSNESS INDUCED CHANGES IN HUMAN BLOOD CIRCULATION A.M. Genin, V.G. Shabelnikov, N.M. Asyamolova Institute of Biomedical Problems, Moscow, USSR

The successful space advanced technology application necessitates the closest cooperation with the biomedical investigations. The unfavourable weightlessness effect on human blood circulation presents an acute biomedical problem. The settling of this problem can't be obtained without cooperation between experimental studies and up- to-date computer simulation methods. The orthostatic collapse - fainting response to head- down tilting - reveals in the extreme form the blood circulation deconditioning. Quantitative criteria to prophesy the orthostatic collapse are practically absent now, for its nature is not clear. Alongside with it there is a qualitative resemblance between the collapse revealiation and various dynamic systems transient beha- viour when they become unstable. At this work the diagram of cause-consequence correla- tion determining the cardio-respiratory system reaction on orthostatic exposure has been developped on the basis of special model experiments and postflight observations. The diagram contains a number of feedback loops, which stability has been investigated mathematically* Experimental and mathematical modelling results have determined two main phenomena that lead to the orthosta- tic collapse. That is a decrease in mean arterial blood pressure and arterial hypocapnia, resulted from relative hyperventilation* The interaction of these two factors exerts a cerebral blood flow decrease. In its turn the lack of cerebral blood flow causes hypercapnia and hypo- xia of brain tissues stimulating the respiratory centre and enlargening hyperventilation* Simultaneously the ce- rebral hypoxia depress the vasomotory centre* Its vaso- constrictive effeot on peripheral vessels decreases hence systemic arterial blood pressure falls* This kind of consequences can create a "vicious circle** which may lead to the cerebral blood flow reduction and faintness. Moreover, the unstability can appear in stroke voluae selfregulation loop which exists according to Starling*s "law or a heart11* For this the circulating blood volume should be reduced. The obtained results will help to check the sugges- tion that orthostatic collapse is the revealiation of unstability in a oirtain feedback loop regulating blood circulation* - 197-

IAP-83-197 The Oxygen Regimen in the Human Peripheral Tissue during Space Flights H. Haase1, E.A. Kovalenko2, A. Vacek3, M.P. Bobrovnickij2, B. Jarsumbeck , V.K. Semencov , Z. Sarol , J. Hideg-3, K. Zlatarev6

1 Inotitute of Aviation Medicine, Konigsbriick, GDR 2 Institute of Medico-biological Problems of the Ministry of Health of the USSR, Moscow, USSK 3 Institute of Biophysics of the Czechoslovakian Academy of Sciences, Brno, Czechoslovakia 4 Institute of Aviation Medicine, Y/arsaw, Poland 5 Institute of Aviation Medicine, Kecskemet, Hungary 6 Institute of Aviation Medicine, Sofia, Bulgaria

Abstracts

A survey of the results of the experiment "Oxygen" carried out within the scope of the "IKTERKOSMOS" program in mem- bers of the permanent crews and of international visiting expeditions to the Sowjet orbital station "Salyut-S" ie given. The investigations were conducted by means of a special board-oxymeter, operating on the polarographic principle. The device was developed in the Czechoslovakian Socialist Republic in cooperation with Sowjet experts. An uncovered platinum needle electrode served as the measuring probe. Intracutaneous oxygen partial pressure (pOp ic) and local oxygen utilisation were determined in the skin of the forearm. During the 7-day space flights of the international visit- ing expeditions a significant decrease in pC>2 ±g by 3.28 kPa (24*7 mm Hg) was observed. Local oxygen utilisation reduced significantly by 0.44 kPa {3*3 mm Hg). During hy- perventilation testing after return to earth a statisti- cally significant reduction in the peak value by 1.39 kPa (10.5 mm Hg) was noted. In the long-term crews of the orbital station "Salyut-611 (day 32) the highest reduction in pO2 ic of 3»8 kPa (28.5 mm Hg) and the absolutely lowest value of 3*4 ± 0.5 kPa (25.6 + 4,0 mm Hg) during space flight were measured. The - 198 - decrease in local oxygen utilisation during the flight by 0,8 kPa/rain (5»6 mm Hg/min) was greater than that of the visiting crews and demonstrated, by 1,0 i 0»2 kPa/min , (7.7 i 1»3 mm Hg/min) the absolutely lowest value. The results of the experiment "Oxygen" indicate the im- portance of investigating the dynamics of the oxygen re- gimen for medical control of the crew members both during the space flight and during the readaptation phaoe after return to earth* INPLUEWCK OF SHORT-TERM SPAOK PLIGHTS AND SIMULATED WE.TGHTLES:ME:JS ON THE RENAL WATER AIID TONS EXCRETION A.I. Grigoriev, B.R. Doroohova, V.J. Institute of Biomedical Problems, Moscow, USSR

Bsaontia] adaptory changes of function of different organism's systems we.3 noted after short-term apace flights. Changes of water-salt metabolism play an im- portant role in this process. 10 cosmonauts after 7-3- day space flights and 33 healthy men after /-8-day im- mersion and antiorthostatic hypokynesia -8° and -15° were examined to study mechanisms of hydro-ions status1 reform. Our investigations allowed to establish that the dai- ly rhyth of water, sodium, potassium and osmotically ac- tive components was changed in the first day after the space flight. Their maximum excretion was observed in the evening hours, while before the space flight the maximum was reached in the day hours. Besides their exc- retion was lower than control and was more pronounced in the morning and day hours. Simultaneously the rate of aldosteron excretion in the urine increased by 1,5-2,5 times. Similar changes were observed after the investi- gations with simulated weightlessness. The peak water and ions excretion shifted to later hours as compared with control. The aldosteron concentration in serum and plasma renin activity exceeded the initial levels by 50- bO%, which was probably the n?.ain cause of increased so- dium reabsorptibn in renal tubules. The Cortisol concen- tration in serum also increased surpassing the control level by almost 30$. As distinct from monovalent ion3 the daily rhythm of calcium and magnesium excretion didn't differ from ini- tial one in all the investigations. The renal calcium and magnesium excretion after the space flights waa low- er than preflight. However, it surpassed the initial le- vels in the next day and was more marked in the evening hours. At that the PTH concentration in serum was more than 3 times higher than before the space flights. The bivalent ions excretion decreased in the first day after immersion and antiorthostatic hypokinesia. However, in the evening and night hours some subjects showed high calcium and magnesium excretion and it waa more pronoun- ced in subjects over 45. Simultaneously there was obser- ved an increase in serum calcium concentration which could result in increased nephron loading in its turn leading to calciuresis* growing. CHANGES IN BLOOD PROTEIN REGULATION AS A POSSIBLE MECHANISM OP SOME DISORDERS IN FLUID AND ELECTROLYTE METABOLISM T.A. Smirnova, V.I, Pofanov Institute of Biomedical Problems, Moscow, tfSSR

The investigations of effects of weightlessness on human organism reveal in most cases a decrease of body- mass, shifts in fluid-electrolyte balance, growth of blood hydrophilic capacity (N.N. Gurovsky, A.D. Egorov, 1976). The biochemic analysis discovered changes in content of some hormones in fluids of the organism which appear to result from changes in regulatory me- chanisms (A.I. Grigoriev et al., 1982). One of the reasons for the loss of^cosmonauts' body mass is explained by the hydratation of the organism which in its turn is connected with the shifts in fluid-electrolyte balance during space flights (I.S. Balahovsky, 1978; P.C. Rambaut et al., 1979; A.I. Gri- goriev, 1982, Eu.I. Vorobiev, O.G. Gazenko et al.t 1982). Plasma proteins are responsible for a number of the most important functions in the organism and among them maintenance of a constant colloid-osmotic (oncotic) blood pressure and subsequently, balanced fluid distri- bution between vescular and extravescular spaces of the organism. Oncotic blood pressure is one of the core ele- ments of the system regulating its protein content. Belonging to colloids the plasma proteins enforce reten- tion of fluid in the blood chennel. The albumins play here especially important role. The fall in the albu- mins' quarter in the blood serum is accompanied by dis- orders in calcifexy. The pathogenesis of fluid-electrolyte metabolism and dehydration of the organism in weightlessness, in our opinion, is related to changes in the level of the onco- tic blood pressure effecting the synthesis of serum al- bumin in the liver. The liver regulation of the blood albumins is caused by changes in the volume of plasma and in the colloid-osmotic pressure which in their turn result from the disappearance of the hydrostatic pres- sure gradient in the blood system (with the influx of the blood to the upper part of the body occurs its re- distribution in the organism). - 201 -

MINERAL METABOLISM AND ITS HORMONAL REGULATION DURING 1 20-DAY HEAD-DOWN TILTING B.V.Morukov, L.G. Pozharskaya, M.S.Belakovsky Institute of Biomedical Problems, Moscow, USSR As known, the importance of metabolic changes incre- ases with flight time. V7eightlessnesa effects were si- mulated during 120-day head-down tilting (-4.5°). Throughout the exposure 6 healthy volunteers were kept on a controllea diet. The following parameters were messured: electrolyte balance, blood content of ions, parathyroid hormone (PTH) and calcitonin (CT), and hyd- roxyproline excretion in urine. During bed rest the negative balance of calcium, mag- nesium and phosphorus was 17»0 + 3»5 g, 4.8 +1,8 g and 16.0 i 6.2 g, respectively. Beginning with be*d rest days 15-17, renal excretion of hydroxyproline increased sig- nigicantly and rentainsd elevated as compared to the pre- test level. Activity of Ionized calcium in serum during the bed rest study was much higher than pretest. The concentra- tion of total calcium increased significantly in the second half of the study. The content of magnesium and phosphorus also tended to grow. The PTH concentration during the bed rest atudy was higher than pretest* The CT content increased signifi- cantly on bed rest day ;?8 and later on decreased sub- stantially as compared ;o the pretest level. Thus, prolonged head-down tilting leads to the nega- tive balance of electrolytes in muscles and bones and to the ioni". changes in blood. One of the major factors responsible for the shifts is a change in the hormonal regulation of calcium-phosphorus metabolism. The prin- ciples of an integrated evaluation of mineral metabolisa in bones and biochemical parameters showing metabolic changes in muscles and bones are discussed. - 202 -

IAF-83-201 EFFECTS OP GRAVITY-INDUCED CHANGES IN fUIMUNARY BLOOD VOLUME ON VENTILATION A.I, Dyachenko, V.G. Shubelnikov Institute of Biomedical problems, USSR Ministry of Health, Moscow Two effects of gravity on lung mechanics have been theoretically investigated: I) lung compliance decrease during an increase in pulmonary blood volume and 2). ef- fecta of tidal changes in pulmonary blood volume on ven- tilation distribution. Transition from normal gravity to weightlessness re- results in blood redistribution, in particular, in pul- monary blood volume changes. Increase of pulmonary ca- pillary blood volume enhances alveolar-capillary membra- nes 'strain. Alveolar walls tension and lung elastic re- coil increasei while lung compliance decreases. Mecha- nisms of this phenomenon is studied on the basis of mathematical models of alveolax sheet flow and cubical alveoles* Nonlinear dependence of alveolar-capillary membranes' tension upon its area is taken into account. In future such models may be used for noninvasive es- timation of pulmonary capillary blood volume from lung compliance in weightlessness and G-load conditions. Mechanisms of gravity-induced unevenness in ventila- tion distribution remain unclear. We used a model of . fluid-like behaviour of lung parenchyma to analyse tidal changes in pleural pressure and ventilation distribution, taking into account that parenchyma density depends not only upon alveolar strain, but also upon pulmonary blood volume, pulmonary blood flow model in which vessels are considered aa a sustem tf collapsible tubes distributed in parenchyma was used for calculation of vertical dis- tribution of pulmonary blood volume. Tidal changes of pulmonary blood volume are shown to significantly affect ventilation distribution. An increase in inspiration pulmonary blood volume reduces ventilation in the depen- dent part of the lungs. Ventilation distribution during diaphragms 1 and ribe cage respiration in conditions r>f * normal and increased gravity is investigated. - J.03 -

GE1IERAL MIMICAL RESULTS OP THK SALYUT-6 - SOYUZ LONG-TURK SPACE PLIGHTS Ye.I. Vorobyov, O.G. GazenRo, A.M. Genin, A.D. Bgorov, Yu.G. Nefedov, Ye.B. Shulzhenko Institute of Biomedical Problems, Moscow, USSR One of the main results of the medical investigations conducted onboard the orbital complex Salyut-6 - Soyuz was to demonstrate that man can maintain motivated and productive activity, operator functions included, throug- hout a prolonged space flight. Observed changes in bodily functions do not seem to build up with an increase in flight duration from one to six-seven months, provided the cosmonauts follow the pre- scribed schedule of physical training and a rationally organized alteration of work and rest periods. Medical investigations focussed on the systems of the human body which were expected to undergo significant changes in conditions of prolonged space missions. Cardiovascular studies showed that weightlessness in- duced blood redistribution in different parts of the or- ganism, which tended to normalize in the course of the flight. Postflight orthostatic and exercise decondition- ing was observed. However, these changes were transient and independent of flight duration. One of the most important findings of the 185-day fli- ght was the fact that inflight venous pressure in the forearm, calf and jugular veins was found to be approxi- mately the same. These findings are important for gain- ing a better insight into the hemodynamic changes in weightlessness as well as for working out effective pre- ventive measures to check their development. After 6-month flights during which various counter- measures were employed in full, mineral losses from the heel bone were 3«2-8.3 % which is significantly less than after a prolonged bed rest. After flights of three to six months duration there was observed a slight drop in the erythrocyte count that did not exceed the level of changes observed after shor- ter flights. These changes may be induced by a compensa- tory decrease of the circulating blood volume occurring early in the flight and the much more rapid recovery of plasma than of the red blood cell count postflight* Thus, our medical investigations did not reveal any significant changes in the vital systems of the human body that could prevent further controlled increase in flight time. The crewmembers did not report any psychological prob- lems that interfered with their performance of the flight programme or induced any psychic disturbances. - 20* -

Thus, after space flights and simulated weightlessness there were observed changes of daily rhythm of renal exc- retion of water, sodium* potassium and osmotically active components which were mainly determined by hormonal acti- vity changes* IAP-85-^05 TIED ACCIJRANOY OF OFfcWHVATION Kill) FLIGHT JJAJWY 1MPKOVM1SNT N.V.Krylova, A.K.Bokovikov Institute of Psychology of the U 53R Academy of Sciences Moscow, USSR A study of peculiarities of cosmonaut-operatur actLvi- ty in observation tasks has been conducted in order to eva- luate future direction of improvroent of apace flight safty. Case-studies are necessary to .justify incorporation of various observational tasks into a space flight program. We studied operator's activity in visual information processing under the conditions of time deficit. Methodolo- gy and estimation criteria have been worked out to provide for objective qualitative estimation of operators observa- tion activity. A detailed study of this type of cosmonaut's activity forms an important task as cosjnic data (e.g. on geological formations of forming cyclous) nre unique and very infor- mative. Cosmonaut's activity in visual monitoring and observa- tion during space flight consists of a variety of types: - observation of the Earth surface to meet the needs of geology, geography and agriculture; - observation of atmosphere with meteorological survey pur- poses aimed at timely warning about natural disasters; - various astronomy observations; - identification of space flying objects; - visual monitoring of approach and docking of a spacecraft with an orbital station; - monitoring of spacecraft installations data etc. Here another important task arises: to improve accuran- cy and reliability of observations by learning and trai- ning. Accurancy is most important parametr of monitoring spa- tial position of space objects during approach and docking. Operator's activity when determining angulas positions of the orbital station were studied on a facility simulating certain regimes of a space flight with the help of TV-pic- tures. The results permitted to delimit acceptable clear- ness of a TV-picture. Changes of strategie in operator's activity in the regime of approach has been demonstrated. - 206 -

IAF-HJ-209

INTERNATIONALLY SUPPORTED DATA ACQUISITION FOR SOLAR SYSTEM EXPLORATION IN THE 1990's (*) M. S. Reid, P. T. Lyman, 0. W. Layland, N. A. Renzetti Jet Propulsion Laboratory California Institute of Technology Pasadena, California, U. S. A. This paper suggests a possible strategy to enhance the ability of space agencies to support a challenging Solar System Exploration Program without requiring major new investments in ground communi- cation facilities. The basic approach coordinates all the world's large microwave antennas that can be applied to deep space data acquisition. This would involve as a minimum all the dedicated deep space reception facilities of individual space agencies existing in the 1990's. The total deep space antenna figure of merit worldwide will be significantly greater than that of any one agency. The temporary incorporation of suitable non-dedicated antennas could provide further significant increases. Arraying of these antennas would enable more effective support of special events at higher telemetry rates than could otherwise be supported by any one agency, without requiring any nation or consortium of nations to invest in the development, Implementation, and operation of the extra aperture that would only be needed a small fraction, of the time. More generally, sharing of support gives more flexibility for peak loading, and enables better location of coverage; e.g., Northern stations for Northern spacecraft, flexibility in time (longitude) for encounter'events, etc. Also, Individual nations or agencies would have access to worldwide data acquisition, even when arraying is not needed.

(*) The research described in this paper was performed by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. - 207 -

As a principal benefit of multi-national or multi-agency arrayiny, far outer planet encounters could be supported with a data rate several times that which any single nation or agency could provide. During cruises, however, such arraying would ordinarily not be invoked, as the needed communications and capability tracking could be supplied by a dedicated single-agency capability. The long-term organizational arrangements needed to enable this multi-national or multi-agency support are rather challenging and need to evolve between now and the 1990's. However, the potential for support of better solar system exploration missions than any one nation could afford alone makes it desirable to meet the organizational challenges. Individual space agencies will then be able to plan more exciting, rewarding, and cost-effective deep space missions. The facilities that can be incorporated into the support configuration could include not only dedicated deep space antennas, but also radio astronomy antenna. These facilities would be equipped with low-noise receivers at the deep space frequency bands and with the signal processing equipment needed to preprocess the received signal so that it can be combined with signals from the other array elements. Such equipment would be provided to the radio astronomy facilities on a permanent or temporary basis, potentially enhancing their capability in radio astronomy. Thus, both radio astronomy and deep space exploration would benefit from the incorporation of radio astronomy facilities into the inter- agency array. The signal combining equipment for antenna arraying could evolve from thai, already developed for intracomplex arraying in the U. S. NASA Deep Space Network (DSN). In this, all the large apertures at each of the three facilities of the DSN are arrayed together. This paper discusses the technical, economic, and organizational issues involved in the multi-national, multi-agency arraying concept. The current DSN activities in inter-site arraying are described, with emphasis on the configuration being prepared t« support Voyager-Uranus. The conclusion is that the concept of international cooperative support for deep space data acquisition is feasible, cost- effective, and highly desirable for multi-national solar system exploration of the 1990's and beyond. - 208 -

Reference No. IAF-83-210

GALILEO SPACECRAFT INTEGRATION: INTERNATIONAL COOPERATION ON A PLANETARY MISSION IN THE SHUTTLE ERA

Richard J. Spebalskl

Jet Propulsion Laboratory

The Galileo Mission Is designed to greatly expand our scientific knowledge of the Jupiter systea. The mission requires the ability to acquire scientific data on the , the atmosphere of Jupiter, and the Jovian satellite system. To achieve these requirements a spacecraft concept utilizing separate elements, a Jupiter orblter und a Jupiter probe, wae chosen. Insertion of the orblter spacecraft Into Jupiter orbit requires a propulsion subsystem (Retropropulslon Module (RPM)) of significant proportions and complexity. The apacecraft system design plaoed additional functional demands on the RPM, e.g., attitude control and trajectory correction requirements. The resulting spacecraft design embodied a Retropropulsion Module that was a significant element of the spacecraft containing a major proportion of the spacecraft total mass and a key element of the overall structural and thermal design. By mutual agreement between the National Aeronautics and Spaoe Administration (NASA) and the Bundesminlsterium fuer Forschung und Teohnologle (BMFT), the responsibility for the design, development, and mission performance of the RPM was assigned to the Federal Republic of Germany.

The major mission and spacecraft requirements on the RPM are presented. The RPM as a major functional, element of the Galileo spacecraft Is described. Complications of the integration process due to the international interface are identified. Challenges associated with integration with new launch vehicles, the Shuttle and upper stage, and their relationship to the RPM are presented. The resulting integration process involving mission and propulsion performance, reliability, mechanical and thermal interfaces, :nd safety is described.

The integration process of the Galileo spacecraft and RPH and the results of that prooeas to date are assessed and presented. Finally, considerations and recommendations for future missions involving international cooperation of this nntura ar« presented. IAF-8 1 -HI

A RECOMMENDATION TO CHCCK THE LAYERED STRUCTURE OF PHOBOS KY IN SITU MKASURKMKNTH

by

E. Illes1, A. Horvath1, F. Horvath2 and A.

1 Konkoly Observatory, H-1525 Budapest, Box 6 7, ihinqaiy 2 Department of Geophysics, Eotvos University, H-.1O83 Budapest, Kun B. ler 2., Hungary 3 Satellite Geodetic observatory, H-1373 Budapest, Box 546, Hungary

The complex system of linear features on ['hobos •-- thf» moon of Mars -- found by the Viking Orl>itf?rs In 1976, can be classified morphologically into 5 types <"iecor dinq to their appearance as well as their geometrical distri- bution on the surface. One kind oF grooves appears to form arcs of small circles normal to the rhobos-fiars di- rection. We are convinced that these qroowes are the surface manifestation of layering within Phobos (flies el al., 1981) which could have been formed on a mu''h larqei and geologically active parent planet.

Here we suggest some measurements to check whet hei Phobos does have a layered structure or not. The suggestion con- tains remote sensing measurements (particularly determi- nation of the magnetic field by and by elec- tron reflection method) by a spacecraft around Mars as well as surface measurements (active seismic vefIp^tion experiment) by a landing module on Phobos.

REFERENCE

E. I lies and A. Horvath: On the Or I q In of the on Phobos Advances in Space Research Vol.1, pp. 4 9 - R •*. Pergamon PTPSR Oxford 1981.. - 210 -

IAP-83-2J2 THE RESULTS OP INVESTIGATION OP BOMB REGIONS OP VENUS BY BISTATIC RADIOLOCATION Pavelyev A.G., Yakovlev O.I., Milekhin O.E., Kucheryavenkov A.I* Institute of Radioengineering and Electronics of the USSR Academy of Sciences* Marx Avenue j8, GSP-3, Moscow, USSR

New data about characteriatlce of the surface and soil density are presented. This data were revealed dur- ing bistatic radiolocation experiments using Venera-JO satellite. The resolution was varied in the interval 4 to 20 km. The first two observed regions are disposed in the south hemisphere of Venus and are contained in the inter- val of VenerocentrAc coordinates! -33° • -34° latitude, 156°-170° longitude. The third and the forth regions are disposed in the interval -26° - -22° latitude and 2J5°- 232° longitude. The fifth region is located in the north hemisphere in the interval 14°-J6° latitude and 34O°-358° longitude. The value of dispersion of small-scale slopes, ir , varies between 0.4° and 0.8° in the first three re- gions. The corresponding value oi" the roughness parameter, C, is contained in the Interval 1,3*10 O.5«10* . This value jr is equal approximately one-tenth of the magni- tude jf corresponding to Lunar mare. The radius of corre-

lation, Z9 , and the dispersion of height, A h , of small-scale roughness of surface were determined from measurement of the intensity of the coherent component corresponding to reflection of radiowaves from smoothed areas* The values 5, and (ikPr^are contained in the intervals 30m £ r £ 300m and 20cm s. QSFJ^&O cm corres- 0 QJ pondingly* The roughnes0 s of relief increased in the fourth and in the fifth regions with the value Jf varying bet- ween 0.5° to 2.0°, There are some features of long-scale relief in the observed regions* Some of this features may correspond to slopes of hills with values containing in the range 0.6°-4.0°. Corresponding changes of relief height are contained in the interval 0*2 to 1.5 km* The maps of long-scale features of relief are given* On the map of the first region there are two ring-.ike structure* The diameter of this structures is equal approximately to 70km. The soil density in the fourth region is contained in the interval Uβ to 3.1 g/cm3 • The comparison of the results of bistatic radioloca- tion with data of measurements of the Venus relief provi- ded using "Pioneer-Venus'* orbital block is given. - 211 -

Sl'EClPTC FEATURES UP TUB DttfUttN AN!) DEVELOPMENT OP THE ONBOARD aciJSMTIPJC fAYJ,OAD FOR COMET HALW5Y STUDIES (VE'IA T.A. Ohu^ari- bn (U3SR), b'abo (Hun-

The configuration and arrangement of tfie Bclentifjc payload an the flyby apanpnraft which by the begin- ning or March 1986 are to fly at a distance of about 10.000 km from the nucleus of Comet.Halley. At a space- craft relative velocity of fiO km a , the duration of the final atage of the approach should be aeveral minufcee which excludes a possibility of controlling the scienti- fic payload by commanda from the Earth, Time the pi.vioau will be controlled by a stand-by onboard loRjio scheme ba- sed on the adaptive principle. Dust danger (inpacts of duet particles with a inasa upfco- T O g), posos additional requirements to the scientific payload. precaution measu- res are described for the instrumentation units mounted at outer panels* To conduct precise wave experiments (studies of the effects of solar wand, interaction with the oometary plasma) demands a higher electromagnetic "purity". The laboratory modelling necessary to solve possible technological problems Jβ described. - 212 -

IAF-83-217 DESIGN, PERFORMANCE AND RESOLUTION OF THE X-RAY TELESCOPE ON ROSAT

by M. Stania and E. Bachor

DorrHer System GmbH D-799O Friedrichshafen, Postfach 1360 West Germany

ABSTRACT This paper deals with the large X-ray telescope on ROSAT (Rbntgensateii11), a X-ray satellite which will be launched by SHUTTLE 1n 1987. The ROSAT project Is managed by the BMFT/DFVLR and the Institute for Extraterrestrial Physics at the Max Institute for Physics and Astrophysics (MPE) Is responsible for the scientific program. The scientific pay load of this satellite consists of a large X-ray telescope with a focal length of 2400 mm and a diameter of 830 mm, and a XUV wide field camera with a focal length of 530 mm and a diameter of 580 mm. The X-ray telescope (XRT) will work 1n the energy range 2 keV to 0.1 keV (6 to 120 angstrom), whereas the energy range of the wide field camera (WFC) will be 0.21 keV to 0.04 keV which extends Into the as yet largely unexplored wavelength region of 60 to 300 angstrom. Prime objective of the ROSAT mission during the first half year is to perform a complete sky survey 1n the energy range 0.04 to 2 keV. Second objective will be a detained observation of selec- ted sources with respect to spatial structure, spectra and time variability. These observations will take place during a 1 year observation period which will follow the all sky survey. In particular, the structural and thermal design of the X-ray telescope will be discussed, indicating the specific problems and solutions. Figures concerning the resolution capability of the high resolution mirror assembly, which has been developed by CARL ZEISS In cooperation with DORNIER SYSTEM, MPE and MBB, will be given considering the thermal 1n-orb1t loads. A fiducial-1ight-system will be presented, which allows monitoring of local displacements and thermally Induced bending effects within the telescope. An analysis of the particular errors within the telescope will be given. The contribution of the particular error to the overall telescope error will be discussed taking into account statistical methods of evaluation. Based on thus accuracy figures and structural-thermal pro Vs the telescope performance can be deduced. The ROSAT design will result In a telescope resolution of better than 30 arcsec (68% power radius) during the all sky survey scan mode using position s<*n*1t1vp nrnnnrt inniii counters with about 13 arc-sec resolution as X-ray detec- tors. During the pointing mode the telescope resolution will be better than 10 arcsec using a high resolution Imager with a resolution capability of about 1.8 arcspc as X-ray detector. - 214 -

IAF-83-218 VIKING - A Low Coat Scientific Satellite - Description and Test Results Johnny Andereson SAAB SPACE AB INTRODUCTION The main purposes with the VIKING satellite project are to perform advanced magnetospherlc and auroral research and to increase Swedish industry's capabilities in satellite development work. Saab Space AB Iβ prime contractor for the development of the VIKING satellite on a contract from the Swedish Space Corporation. This effort includes project management, systems engineering, interface control and coordination, payload development, TTC development, platform procurement, payload and satellite integration and teet. The VIKING program Iβ quite unique in Its low cost approach. Launch cost is kept to a minimum through the use of a load carrying main structure which carries the main satellite SPOT, and which permit8 the efficient use of the extra payload volume available. Satellite cost is minimised through the use of existing, qualified unite, protoflight model philosophy, efficient working methods and routines etc. The VIKING low cost features are readily adaptable to a wide va- riety of small satellites, since the same concept can be used with moderate modifications for different payload types, different orbits, different attitude control principles, higher data rates etc. Saab Space is now conducting environmental teetlng of the VIKING satellite at RSTEC in Holland. Viking is presently planned to be launched by Arlane from in French Guyana early 1985. SCIENTIFIC PURPOSE The main purpose is nagnetospheric and auroral research by per- forming measurements with high data ratea and high resolution in those regions of Earth's magnetoephere where charged particles are accelerated to high velocities along the magnetic field lines, cau- sing auroral phenomenae at lower altitudes. Main region of inte- rest is altitudes between 4,000 and 15,000 km at high latitudes with emphasis on winter season measurements. Typically, high data rate experiment measurements are made ~ 80 min per orbit. Mission time (design lifetime) is 8 months, although there 1* a good chance of much longer satellite lifetime. The scientific experiments and principal Investigators are:

o Electrical fields. Dept of Plasma Physics, Royal Institute of Techno- logy, Stockholm, Sweden• o Magnetic fields.Applied Physics Laboratory, Johns Hopkins University, USA. o Energy and angular distribution of charged particles. Klrtina Geophysical Institute, Sweden* o Electromagnetic/particle wave phenomenae. Danish Space Research Institute, Denmark,and Uppsala Ionospheric Observatory, Sweden. o Ultraviolet Imaging of the aurora. Dept of Physics, University of Calgary, Canada.

TECHNICAL DATA

Orbit Apogee 15,000 km, perigee 822 km, inclination 9R.7°, orbital period 4.5 hours

Configuration Height 0.5 m (0.9 m incl PBH nozzle), diameter 2m (eto wed booms), mass 530 kg at launch (Incl. —263 kg for the PBM) i Structure Main structure is a cylindrical aluminum tube, dla 1.2 m, height 0.5 m, thickness 6 mm, giving adequate stiffness and strength to carry SPOT.

Communication S-band link with ground station. 2.5 W transpond er output power. Two conical log spiral antennas giving full spherical coverage. Two telemetry formats, one high data rate (experiment mea- surements) with ~ 55 kblts/s (8 bits/word), and one low data rate (house keeping) with -»1 kblts/s. 128 on/off command channels, 1 kbltn/a- Timer for acquisition phase events and attitude control switching signals.

Power Consumption 120 W during exp. data taking, 40 W in housekeeping mode. Eight bodyfixed solar arrays provide 80 W. Battery provides backup power during eclipses and peak power consumption. Unregulated power bus 28+4 V, decentralized converters.

Attitude Control Magnetic control via ground station to maintain spin rate 3 rpm and spin axis pointing perpendicular to orbit plane (cart- wheel mode). Attitude data from earth sensor and Run sensor (bark-up data from exp. magnetometer). Torqutng by two magnetic colts commande>i from the ground station. Passive nutation damping by fluid filled to- roidal tube. Spin and despin rockets for spin rate adjustment before and after PBM burn.

Piopulslon STAR 26 C solid propellent Perigee Boost Motor (PBM).

Thermal Control Louvers, multilayer insulation, paints etc

Experiment booms Four wire booms, 40 in each; two axial booms, 4 n each; two radial stiff, booms, 2 m each. - 216 -

Paper-N° 1AF HJ-222

A space-telescope able to see the planets, and even the satellites, around the nearest stars.

C. MARCHAl. ONERA - 92320 CHAT1LL0N - FRANCK

The NASA and ESA are building a space telescope that they will launch in 1985 on a low circular nrbit at an ;iltiiin1fj of about 500 to 600 km.

That revolutionary new telescope will avoid the almus pheric screen and will represent a major step in many field;- with respect to existing telescopes. It has of course many instm ments (wide field camera, planetary camera, Faint objeit lameia, faint object spectrograph, etc..) and wi)j certainly be ! tin source of many great discoveries. The astronomers have alieadv prepared many series of experiments and observations in all fields of astronomy.

However, and it is a surprise, the space telescope will be unable to see directly the planets around the nearest stars, It has already the power necessary to see them but , in spite of an excellent coronograph, the light of the star has a much too large dazzling effect and the astronomers must look for planets through the old indirect ways (irregularities in the motion of the star etc.).

The simplest pictures of an outer planetary systnn would give us much more informations, how to get them ?

A coronograph fight the dazzling effect of a powerful source of light and its efficiency increases with its distance from the telescope. The solution of our problem can thus be obtai- ned if we use as coronograph a suitable screen in front of the space telescope at a distance of the order of lO'tofO* kilometers. Note that the best coronograph is not a circle, it has a beautiful star shape taking account of the undulatory and electromagnetic nature of the light. - 217 -

Of course such a possibility requires a space telescope and a screen far from earth : they need a small relative motion for long time exposures and the space telescope must be at least at five or six times the distance of the Moon, futthermore, if the exposure time is of the order of one day, the Sun al traction and the corresponding accelerations require that the direction of the observed star be at about 90° from thai of the Sun. Each star can thus be observed with a long exposure only twice a year. On the other hand the size of the screen is between 100m and lkm, i.e. the size of the sails projected for the years 1988- 1990 and easily maneuverable with the solar magnetic field.

Let us note a final point : the space telescope of 1985 will have the power necessary to see the full Moon from the distance of oc Centauri, but the image of that full Moon will fall on the pixel receiving also the image of the Earth and we need ten times smaller pixels to separate Earth and Moon. It is for instance possible to put these small pixels at the center of the image with larger pixels all around (as they are in our eyes). It is also possible to improve the picture with a secondary annular screen of 60 meters, that screen intercepts the first negative ring and multiply by nine the received power, quarter moons and even crescent moons become visible.

Thus it is within our means to obtain direct pictures of the nearest outer planetary systems. It seems that single stars represent our best hopes, for both cosmogonic and celestial mechanics reasons (it is also simpler to use only one large screen). Within ten years we should have taken pictures of several outer planetary systems. - 218 -

IAF-83 223

SATELLITE TECHNOLOGY DEVELOPMENTS IN GRAVITY RESEARCH by Vincent L. Pisacane Associate Head, Space Department The Johns Hopkins University Applied Physics Laboratory Laurel, Maryland 20707 Daniel B. DeBra Professor, Department of Aeronautics, Astronautics and Hechanical Engineering Stanford University, Stanford, California

ABSTRACT This paper gives a review of spacecraft technology that is being developed to obtain a better understanding of the nature of gravi- tation and the gravitational field of the earth. Gravity is the weak- est of the fundamental forces and the least understood. It is the primary force at planetary distances and its understanding is inherent to the study of cosmology. Its experimental laboratory includes the earth, the solar system and the stars. On the other hand, the gravi tational field of the earth permeates our life every day. Its knowledge is important for surveying, navigation and satellite orbit determination and its spatial variation has been an important source of data on the structure and dynamic processes within the earth. The advent of spacecraft has provided an important tool to the experimental physicist. Spacecraft provide extra-atmospheric vehicles in free-fall whose motion are driven primarily by the gravitational environment. This makes them well suited to precise measurements. Satellites also provide an economical means to cover ail regions of the earth and make observations in the most remote areas.

This paper addresses four technology areas in which meaningful advances are being made so that satellite missions are now under study that should significantly increase our knowledge of gravity. These - 219 -

areas arei Satellite Altimetry, Satellite Tracking, Spaceborne Gravi- ty Gradiometers and Orbiting Gyroscopes.

Spaceborne microwave altimetry has been an exciting source of data which has made possible global determination of the ocean geoid. There have been two altimetric satellite missions, GEOS-3 and SEASAT. A U.S. Navy spacecraft, GEOSAT, is under fabrication for launch in the Fall 1984. The altimeter and the mission are described. An advanced altimeter is also being developed for the potential TOPEX satellite mission. Description of the mission and the dual frequency altimeter is given.

Earth-based tracking of the motions of near-earth satellites have provided data from which global models of gravity of over a thou- sand parameters have been developed. To increase our knowledge a Geo- potential Research Mission (GRH), formerly GRAVSAT-A, is under study. The geodetic data is to be satellite-to-satellite tracking of two low altitude spacecraft to an accuracy better than 2.5 vm s"'. The mis- sion, system concept and spacecraft technology are described.

Instruments based on finite-difference measurements to approxi- mate the gravity gradient have been used for nearly a century. To provide the extra sensitivity and accuracy needed for orbital gravity mapping, designs employing electrically suspended accelerometers (ESA) and several taking advantage of cryrogenic technology are under devel- opment. Current gravity-gradient measurement technology is described.

Einstein's general theory of relativity is a theory of gravi- tation. The corrections to Newtonian theory are so small that no lab- oratory experiment has ever been successfully performed. L.I. Schiff proposed an orbital gyroscope experiment to measure non-Newtonian gravity effects which is under development as the Gravity Probe-B mis- sion. Technology associated with this mission is described. - 220 -

IAF - 83 - 224 ORBITAL GRAVITY GRADtOMETRY THROUGH DIFFERENTIAL MICRO-ACCELEROMETRY A. Bernard, B. Sacleux, P. Touboul Office Nationel d'Etudes et de Recherches Agrospatialee B.P. 72 - 92322 CHATILLON CEDEX - FRANCE

Besides Its Interest for tha prediction of satellite orbits, a good knowledge of the gravitational field is necessary to Improve : - In geodesy, the definition of the dynamic shape of the earth, I.e., the shape of equlpotentlal surfaces that reflect the internal muss distribution ; - in oceanography, the determination of the mean oceanic circu- lation ; - in geophysics, the fitting of more detailed and regional internal structures of the earth. For these purposes, the GRADIO project alas to build a dedi- cated satellite around an instrument designed for measuring the de- rivatives of the gravity field. The orbital gradiometer is composed of several ultra-sensitive acceleroiaeters (107? EBtvBs sensitivity re- quires an acceleration detectivity of IO~12 «e~2 for aim base- line).

The differential measurements between accelerometers give the seconde derivative tensor of the potential but three error sources are present : - the angular velocity of the satellite : effects of the gravity gradient and of the centrifugal acceleration field cannot be dis- criminated. So the latter must be minimized by using a very accurate attitude stabilisation ; - the angular acceleration of the satellite : since It la an antlsym- metrical tensor, It can be discriminated from the angular velocity terms and gravity gradient components (symmetrical tensors). Par- ticular combinations of differential measurements permit either to cancel this error source effect or to estimate the angular acceler- ation and then the angular velocity too { - the sensitivity mismatches between accelerometers : to obviate the corresponding errors, an all time scale factor matching is achieved. The matching process requires to apply to all accelerometere sine wave calibrating accelerations. This Iβ achieved by the use of pairs of unbalanced wheels rotating at well known angular fre- quencies. The design of the accelerometers for GRADIO in based on tun ONERA studies : I) the CACTUS accelerometer which has been especially designed for space applications. Launched on May 1975 (CASTOR-D5B satellite), the data acquired during its 45 months of orbital life has permit- ted to measure the accelerations due to radiation pressures with a resolution of 10"' ms"^ ; II) a three axis accelerometer for navigation, also based on an elec- trostatically suspended proof mass. Each GRADIO accelerometer will use again a proof mass sus- pended by electrostatic means. These accelerometers specially devel- oped at ONERA permit to obtain, _at low frequencies, an acceleration noise as low as 10~*2 me"2//Hz with a measuring range of + 10~4 me"2 full scale. Since D.C. components of some gravity gradient tensor terms are of the order of 3000 E, it is very difficult to take advantage of the high detectivity of the accelerometere. Since, these D.C. com- ponents are not needed for the recovery of the fine structare of the gravity field, they may be filtered out. In this case, the designed gradiometer will provide values of the gravity gradient variations with the accuracy of the all time calibrating system (10~*) as far as It Iβ not limited by the noise spectral density of 10"' E//HE. — 222 —

SPACE HE SEARCH ANB SEISMOLOGT

8, ChapkunoVt** Oo che-r,*, DanoT»lV* Donche^ra, T.HntTiycTmk ,

X.ftuaeiie-r, 0»etnn*-rf»,T»odi>sl»T

Central Laboratory for- Space Reeen?oht Bulgarian Acndoay of Scfences

Abstract The Intercoentoe~Bttlga*la-1300 satellite wae launched on Attguet 8, T98T on a s*«l«circular orbit of height - 900 tarn «n4 lnoltnatlon of 80*2'.Th« **t»ll*t* traneite eroeetnir th* •ir*nl*y

of an «picenter b»for» anf*v«ne» ••rthqnak* mxrmlnwt. Oae*a of earfiiqwakee o# magnittkte larger than 3«7 by th» Siohter seal* ar* stuiiiki Brrth* porloA *f T98i-t'9e?.'rh»» r»eulti froa the- •O'aeuromonte of the- IB8P-IPMP vaT* eo«pl»3t (*loti»«5*or for •leotroetMlie field and ite low frequency flnctuatione nndd detec- tor ef electromagnetic oomponente) are ueee) in the pmrF&rmrme* e* the electromagnetic field* up te 15 kits together with th» AWftP* lnetrtnent (lour energy proton and ion anelyeeir), memauring the charged particle float within the rang* of 200 eT *• 15 keT. Con»pe- rieon wae nade vith reettlte obtained in other epaneberne exp«nri- Mont* by other lnveetlgator*. Preliminary conelue*one nre den* in of poeei.'ble earthquake prediction* - 223 -

IAP-&3-227 TO TIE TIlOIiLZL OF DPJ&CTBUi: ILVK5TIGATIOI! BY TIIE OK-EOARD A1.ALY3ER "VAR11 I.:.A.R3kov, Ya.T.Dub Institute of Physics and Lechanict? Academy of Sciences of the Ukr.SSR The raacne to sphere investigation demands the study of the thin structure of specific regions of magnetosphere, shock wave and . That is why the necessity ari- se of the spectrum analysis performance directly on the board of satellite. The investigation of the electromagnetic cpectnom of the field of shock waves together with a set of another parameters allows to determine uniformly a type of plasma instability developed in the shock wave, to prove theore- tical concepts and so on. The particularity of the expe- rimental study of the thin structure of plasma processes is the necessity of spectrum analysis proceeding with relatively small analysis time I • After the examination of advantages and shortages of different methods of spectrum analysis it was found that the most effective for the given sircumstances is method of digital Fourier transformation (DPT). It allows exe- cute a parallel analysis of some processes in the diffe- rent frequency ranges. DPT technique allows not only to determine the spectral power of low frequency random pro- cesses but also amplitude and frequency of polyharmonical processes components 2 . In the Institute of Physics and Mechanics of Acade- my of Sciences of Ukraine the technique of determination of amplitudes and frequencies of sinusoidal components of polyharmonic processes is developed, which may be used for on-ground processing of spectrum analysis data, transmitted'from the satellite when initial information about polyharmonic composition of analysed processes is presented. The computer-analysator nVAR" designed in correspon- dence with the proposed technique will be used in the in- ternational experiment "Intershock" plaised by the scien- tifical programme of "Interkosmos11 Council in accordance with the International Kagnetospheric Study programme. References I.t'.A.Rakov, Ya.T.Dub, S.I.Klimov et al.I»etodologiches- kije i apparaturnyje aspekty issledovanija tonkoj struk- tury polej v plasme kosmicheskogo prostranstva. Kosmiche- skije issledovanija na Ukrainje,vyp.I4,Kijev, "Kaukova dumka", 1980, p.75-80 (in Russian). S.Ya.T^Dub, K.A.Rakov._Izmjerjeni3e sjpektra^moshchnosti r - 224 -

IAA-83-231 MATERIALS PROCESSING FACILITY - A COMMERCIAL APPROACH by Lawrence R. Greenwood Ball Aerospace Systems Division Boulder, Colorado USA The ability to process materials in space offers an exciting new frontier in materials research. Without the effects of gravity a better understanding of basic material phenomena may be possible, which in turn may lead to improved processes on Earth or the manu- facturing of nev" materials in space. The advent of the space shuttle affords research, ,-s the potential to perform experiments requiring large quantities power, cooling and without severe limitations on experiment weight. Developing and integrating individual experiments into the space shuttle can be very time consuming as well as costly. Economy of scale can be achieved by combining a number of experiments into a common facility that can be integrated, tested and flown aboard the shuttle. This paper will describe a commercial facility that will facilitate access to space for the researcher such that the potential benefits of processing in space can be realized in a cost effective manner. The Materials Processing Facility is a multipurpose experiment carrier designed to carry materials processing experiments aboard the shuttle. The experiments are fully enclosed in canisters, integrated to the carrier and placed aboard the shuttle. The experiments do not see the space environment and are only required to mate with simple interfaces for commands, power and cooling. The carrier receives power (up to 7 Kw) from the shuttle and discharges heat through the shuttle cooling system. The entire system is designed to facilitate the experimenter and to minimize cost. The commercial service 1s an end-to-end service providing experiment check out, Integration to carrier, on-orbit operation, data collection, ex- periment removal and return. In addition the technical design and operation of this facility this paper will discuss other aspects of developing a commercial materials processing venture. In particular there will be a dis- cussion of risk management, insurance, product liability, and shuttle manifesting. The potential return from studying the physics of materials in space 1s great. New insights derived in space may even lead to commercial processing and manufacturing of materials. A commercial facility 1s a key to providing low cost access to the shuttle and to the experimental data needed. - 225 -

IAA-83-233 THE COMMERCIAL CENTAUR FAMILY

W. F. RECTOR, III D. E. CHARHUT GENERAL DYNAMICS CONVAIR DIVISION

The Centaur high energy upper stage has been flown on Atlas and Titan boosters a total of 68 launches and is now being Integrated with the Space Shuttle for planetary, solar exploration, and national defense missions. The stage has demonstrated its high reliability by establish- ing a flawless operational success record during the last twelve years of 42 consecutive successes. During this time, many of the world's largest communication satellites were successfully boosted into orbit, and all United States planetary exploration missions were launched with this vehicle. General Dynamics Convair Division is now pursuing various commercial applications for Centaur. The current Atlas G/Centaur vehicle is already being offered commercially for launching large geostationary communications spacecraft such as direct broadcast satellites. A family of launch vehicles called Atlas II/Centaur, which are deriva- tives of the current vehicle, are also planned for commercial opera- tion. This family will be capable of launching dual spacecraft, e.g., large direct broadcast satellites In combination with a smaller space- craft, or a single INTELSAT VI spacecraft. Centaur in the Shuttle is also considered a candidate for commercialization at some future date, since it offers capability to orbit very large communications space- craft. This activity is being driven by an expanding market of com- mercial and foreign communications satellites forecast during the next decade. The key to success of a commercial Centaur family 1s Its ability to cap- ture an adequate share of the available market which, 1n turn, is di- rectly related to having a cost competitive price. Several approaches are being taken in order to make these vehicles price competitive In today's marketplace. First, the family 1s being designed to launch dual spacecraft which reduces the Individual user cost proportionately. Second, the reduction of Government charges, coordination, meetings, and documentation required under Government contracting Is expected to result 1n significant savings. Third, by planning on a program with continuous production/launch rates and lot buy sizes, the cost Impact of gaps and small quantity buys can be eliminated. Fourth, the added - 226 -

Incentive of commercial earnings potential as opposed to a nearly fixed earnings potential of Government contracting should result In Increased efficiency and productivity. Some additional areas being explored to reduce costs include: reduc- tions in high cost drivers, such as chem-m1111ng, special finishes, extreme tolerances, and over-tight specifications wherever possible; final checkout of the vehicle at Cape Canaveral Instead of San Diego; reductions In the number of launch support personnel supplied from San Diego; and reductions in the Government services suppi led to support the launch. A separate entity called "CommSpace" has been established within the General Dynamics organization. CommSpace will be responsible For marketing the launch vehicle, arranging financing, contracting for the launch, and Insurance arrangements. - 227 -

IAA-B3-234

(MINUMIl'. 01 III HOMMIINK Al IONS SI'Al I '.I (.MINI

by l)f. ,1. A. Vandetikei cMiove

This paper proposes a complete model for assessing the economics of telecommunication1-, satellite systems, accounting for spaiecraft development and manufacturing, launch and operation in orbit, this allows to account for such parameters as mass or lifetime of the satellites, the number and type of payloads, the number of satellites procured and launched, the spare policy, the launch vehicle, the insurance, the satellite probable life (MITF) and the management of the MM(tl segment efforts

Fhe model is divided into four parts: the spacecraft mass model, the spacecraft procurement costs model, the MTFF model and the c'l'rtl * segment cost-effectiveness model. It provides for the rapid solution of a number of problems with a wide range of parameters, such as assessing the influence on space segment economics of the following:-

- certain satellite technologic,

- satellite ami pay load mass

- number of payloeds per spacecraft

- satelIite Iifetime, or

- spare policy.

"Assistant technical Director, European Space Agency, Paris, I'tanre IAA 83 235

Cost Reduction Trends in Space Communications by Larger Satellites/Platforms

Dietrich E. KOELLE, MBB/ERNO Space Division Ottobrunn/FRG

The paper analyses the development trends in communication satellite development and tries to define the most economic solution for the fu ture.

There are three basic possibilities to realise the expected futiite «fc mand in satellite communications capacity:

- larger spacecraft platforms - larger number of smaller spacecraft - modular assemblies. Increase in spacecraft lifetime and transponder technology iniprov&niptti are important economic factors to be considered. It is projected that the growth of communication satellites will continue due to the fact that the cost per channel are decreasing with increasing S/C mass. This is due to better specific capacity, lower specific msl. per satellite and lower specific launch cost. This is demonstrated by cost models for spacecraft and launch vehicles, established with res Us tic reference values. The results show a basic cost reduction by a factor 3 of specific than nel cost for a 4 500 kg satellite compared with an 800 kg spacecraft. Taking into account programmatic requirements for orbital standby and ground space spacecraft, then the optimum satellite size depends on the total required orbital channel capacity. For systems with less than 20 000 channels the optimum satellite size is below 800 kg, for a 50 flfJfl channel system at about 2 500 kg and a 150 000 channel system is most economic with 4 500 kg satellites. The analysis proves also that both satellite clusters with multiple small spacecraft as well as modular assemblies consisting of a number of small modular docked automatically in GEO are not an economic solution, if fhe required launch capability exists for larger satellites. - 229 -

IAA-83-236 Ku-Satellites, C-Satellites and Landlines - A Critical Analysis for NBC's Future Donald Kivell National Broadcasting Company, Inc., New York NBC has distributed television programs to its 200 affiliated stations by terrestrial facilities (landlines) since 1950. AT&T has been the principle carrier. In 1972 NBC began investigating whether satellites could eventually replace landlines, and deliver higher quality and greater flexibility (more services in parallel to the affiliate) for the same cost. Early use of C-Band satellite services confirmed the higher quality goal. Three factors, however, prevented NBC from converting to an all-satellite delivery system: (1) NBC weekend Football required 8 different games to be fed to 8 different regions, and an all-satellite system would have therefore required 8 or more transponders...whereas only a few transponders would have been needed for regular weekday programming. NBC was unable to find a satellite carrier that would guarantee that those extra transponders would always be available on weekends on a longterm basis. (2) NBC estimated that interference from terrestrial microwave facilities sharing the C-Band frequencies would force the C-Band ground stations to be some distance from the TV station, and thus add a microwave link to the cost and quality calculation for most locations. (3) NBC also estimated that the 36 MHZ bandwidth of the C-Band satellite transponders would make it expensive to put 2 quality television signals through 1 transponder in the future in order to reduce the cost of the space segment, or to double the capacity of the satellite to accommodate weekend sports.

NBC's perspective changed when 3 Ku-Band satellites went into orbit for Satellite Business Systems. In 1982, Comsat General, a partner in SBS, approached NBC with some solutions to these problems: (1) SBS could make extra transponders available on weekends, and (2) the wider bandwidth Ku transponders would help NBC's concerns about frequency interference on the ground as well as other uses of the satellite in the future. Comsat also modified SBS-3 to parallel 4 20-watt transponders to make 2 40-watt "high power" transponders to help in offsetting the rain problem.

In 1982 NBC launched an intensive study of satellites. A consulting firm was retained to study the non-technical considerations of shifting the NBC Television Network from landlines to satellites. An investigation of the rain - 250 -

attenuation problem at Ku-Band was done. Potential rain problems would be "rare and manageable" if the Satellite Television System were designed with these factors in mind (1) each ground station antenna would be individually s for the elevation angle, rain rate, and satellite power available at that particular location, (2) uplink power control would be used in most ground station transmitters, (3) the "high power" transponders would be used most of the time to feed the network, and (4) that the following assumptions were valid - (a) the area of a rain cell decreases as the rain rate increases, (b) the height of a rain cell is about 4 km, and (c) the rain attenuation at 12 GHZ is about 1 dB per km per inch of rain per hour.

A video test was conducted on SBS-3 to verify the signal availability to the performance specification of 56 dB 99% of the time, 52 dB 99.9% of the time, and 46 dB 99.99% of the time.

NBC then recommended a Ku-Band Satellite Television System to its affiliates. These were the important advantages: AFFILIATE ANTENNAS (1) would be smaller and potentially lower in cost (2) would be co-located with the studios of the affiliate (3) would transmit as well as receive, if desired (4) would experience a shorter sun-transit outage SATELLITES (1) would be more powerful (2) would have wider bandwidth for future technology (3) would have already been designed for 2° spacing SYSTEM SHARING Other services besides television might be possible within the network because all points were potentially transmit and receive.

NBC will begin to lease a turn-key system from Comsat General this January: (1) a space segment of 5 full-time and 5 weekend transponders that will begin on the SBS satellites and migrate in part to the RCA Americom Ku-Band satellites when they are launched in 1985-1986, (2) a ground segment of earth stations and transportable uplinks, including maintenance, and (3) a remote control system that, will allow NBC and its affiliates to tune and switch ground station receivers, move antennas, and turn uplinks on and off within the Satellite Television System. The full system will be working by mid-1985 if current contract discussions are successful.

NBC believes that the Satellite Television System will be more cost effective, more flexible for future uses, and of higher quality than terrestrial landlines. 83 - 237 Recent Advances in Lunar Base Simulation B. Johenning, H.H. Koelle Technical University of Berlin / FRG In connection with feasibility studies of Space Solar Power Systems the question of using lunar resources was raised and analysed. Results of these studies, particularly of the General Dynamics Convair Division, San Diego, indicated the potential of considerable savings in the con- struction process of SSPS. This and other studies on this subject did not contain detailed systems simulations over a full life cycle, but ,were parametric studies lacking the accuracy and flexibility of simu- lation models. The Technical University of Berlin has undertaken the job to construct such a computerized "Lunar Base Model" consisting of 20 elements (fa- cilities) for production of raw material, construction material,*fabri- cated products, assemblies and gaseous oxygen by nuclear underground explosion. The lunar infrastructure includes both nuclear power plants and a solar power station transmitting energy by laser from libration point to the receiver on lunar surface, a central workshop for repair and extension of facilities and a lunar farm for food production and recreation of the crew. The simulation model evaluates the mass, ener- gy and manpower flows between each element of the system and all others as well as the system environment. System performance is described by 270 relations and 460 parameters of which most are a function of time according to a learning curve. The model run generates information of all the interesting system features on a year by year basis beginning with the first operational year. In order to keep the specific cost of lunar products low the system model takes into consideration the following features: - automation (manpower demand) - reliability (manpower and spares demand) - efficiency (energy and consumables demand) - bootstrapping (terrestrial equipment demand) A standard run over a fifty-years life cycle was accomplished for a mean lunar facility mass of 14 900 Mg, producing at the average 78 180 Mg products for export and 210 500 Mg LOX per year for space transportation purposes. This requires a mean annual import mass of about 2 240 Mg and a mean lunar crew of about 620. The mean annual recurring cost amounts to about 0.90 billion dollars (1980) while the annual fixed cost burden decreases from nearly 1.24 billion dollars to zero after 25 years. The average cost of lunar manufacturing is 8,4 $/kg for export products and 2.1 $/kg for LOX. Cost figures were derived under the assumption of mean earth-moon transportation cost of 128 $/kg payload which at present results from the space transportation model. This paper reports about the results of the latest computer runs - 232 -

analysing same special operating modes such as - no lunar farming (resulting in 8.3 % total cost reduction) - no bootstrapping of the lunar base (resulting in 35.1 % total cost increase) - only 50 % of the nominal production volume (resulting in 33.7 % total cost reduction) Also some parameters of the standard run are varied in order to get some insight into the system sensivity to - specific spare part demand - specific lunar facility mass - specific lunar manpower demand - specific lunar energy demand - specific space transportation cost - development cost of lunar facilities - procurement cost of lunar facilities This paper summarizes in this fashion the lastest state-of-the-art and know-how of lunar base simulation which might also be of great interest in connection with the urgent problem of nuclear waste disposal. At this time extraterrestrial options are gaining in favour and are with- in reach of feasibility. The option using lunar resources turns out to be quite attractive, also from the economical Viewpoint. The lunar base model presented here will be a very useful tool to confirm this statement. - 253 -

IAA-83-239 THEJCONQMICS OF.JPACE. DEVELOPMENT M. C. SIMON 0. STEINBRONN GENERAL DYNAMICS C0NVA1R DIVISION

Access to the resources of space offers the international community an important opportunity to study and improve the global economy. Space communications, space processing, and ultimately space habita- tion, will generate new industries and new ways of meeting human material needs. The government-industry and international partner- ships which evolve to meet the challenges of space development may also provide new avenues of human cooperation, perhaps as great a benefit in itself as the economic value of space. The economic value of space is based on three primary attributes of the space environment: Earth-orbital positioning, microgravity, and non-terrestrial resources. Earth-orbital positioning, the first of these to be utilized, is already providing communications and remote- sensing satellites with their rapidly emerging multi-billion dollar advantage over Earth-based industries. Microgravity offers the opportunity to separate, combine, and purify valuable substances with an efficiency not achievable under Earth-nermal gravity condi- tions. Within the next two or three decades, we may also begin !\ tapping the resources of the Moon and near-Earth asteroids, to pro- vide low-cost fuel and building materials for expansion of space operations. Coupled with these economic achievements will be the development of new social institutions to exploit these advantages. Just as the emergence of the limited liability corporation helped spur the eco- nomic advancements of the Industrial Revolution, new socio-economic channels may be sought for the industrialization of space. Of par- ticular interest are joint government-industry partnerships, which can combine the advantages of social planning and overhead with the indispensable benefits of free enterprise. The political and eco- nomic repercussions of such developments in "social engineering" may be felt well beyond the arena of space. Large-scale utilization of space resources will ultimately depend on the establishment of routine operations in space. America's Space Shuttle was envisioned as an important early step in developing a capability for economical space operations, but ironically it is the development of low-cost expendable launch vehicles which has attracted the greatest interest within the economically-oriented investment com- munity. Some see this as a failure of the Space Shuttle to meet its expectations in providing reliable and economical access to space. Despite these criticisms, the Space Shuttle still holds great promise for delivering economic and social benefits. In order for the Shuttle to achieve its full potential, however, we must keep in mind its origi- nal purpose: to provide access to low-orbit facilities such as unmanned platforms and manned space stations. The establishment of permanent operations in Earth-orbit, with Shuttle servicing, resupply, and expan- sion, represents our next great challenge in space, and an important next step in bringing the benefits of space down to Earth. This report is an analysis of the economics of space development and of how economics is likely to influence future space activities. Section 2 examines the fundamental determinants of the economic viability of any space venture, namely, the costs of doing business in space. A broad comparison of space transportation costs is pre- sented, including data on the economics of a number of current and proposed launch vehicles and transfer stages. Included are expend- able and reusable vehicles, manned and unmanned systems, space-based and ground-based upper stages, etc. Section 2 also provides data on space platforms and space stations, and an assessment of their impact on the costs of space operations as well as space transportation. Section 3 discusses some primary uses of the space environment, and how they are influenced by the cost factors described in Section 2. These uses, which span the three space attributes Introduced earlier: Earth-orbital positioning, microgravity, and non-terrestrial resources, are characterized particularly with regard to their demonstrated and perceived economic benefits. The impact of space transportation and space operations costs are analyzed. The prospects for such future Industries as wristwatch telephones, pharmaceutical production in space, and lunar mining are evaluated, based on their projected costs and market potential. Section 4 addresses institutional options for developing the economic resources of space, with particular emphasis on government-Industry cooperation. The fundamental nature of private-public goods explored. Existing arrangements such as NASA's Joint-Endeavor Agreements are critically evaluated within the context of their effectiveness in meeting four key tasks: financing, development, operations, and market- ing. A discussion of International cooperation Issues 1s also presented. Section 5 concludes the report with a summary of the economics of space development, based on the data developed 1n the previous chapters. - 235 -

13 Th IAA - Symposium on Space Economics and Benefits H.2. Socio-Economics

STIMULATING EFFECT OF SPACE ACTIVITIES ON SOCIO-ECONOMICAL

DEVELOPMENT IN BULGARIA

( K.B.Serafimov)

Summary

The effect of Bulgarian participation in contemporary space studies and uti- lization on socio-economical development in Bulgaria was examined throughout the following items: 1. Cosmization of science and its reflexion on technical progress, industrial development and economical growth; 2. Space technolo- gical transfer and spin-off and their reviving effect on industry, agriculture, transport, communications and social conditions brought by an increase in the intellectualized and science-consuming production; 3. Space industry as an in- dependent factor of economical growth; 4. Direct use of space aircrafts for re- mote sensing, satellite communications, space navigation and other purposes; 5. Activation and engaging of young people in creative work, gaining of indus- trial-economical prestige and publicity on Bulgarian industry achievements; 6. Promotion of the cultural level my means of an indirect influence respective- ly on industry, trade, tourisme and other areas and raising the strife for a re- vival and a creative spirit of society. Numerous examples on Bulgarian space activity and the "Intercosmos" pro- gramme were examined. - 236 -

IAA - 83 - 24?

THE CASE FOR BUILDING A EUROPEAN

ON THE FRENCH MEDITERRANEAN COAST

Authors : G. PIGNOLET, J. COUPY, H. COUSQUER, C. DICHON, and R. PEVNY

After 26 years of space flight and 21 years of manned space flight, we are entering the second generation of space exploration and development, the era of exploitation of the energy and mineral resources of the solar system.

In the perspective of the year 2000, a step-up process is necessary if we want to launch the large masses of materials and equipment: that will be necessary in Earth orbit, before we can rely on ressources from the Moon or the Asteroids. Next to the American and the Soviet space transport systems, the French and the Europeans industries can have their own space transportation system based on an intensive use of mass-produced advanced Ariane launchers. Without precluding the development of more sophisticated launch systems, such an approach would drastically change the technical, economical, and sociological conditions of the European space drive.

Technically, today, equatorial launch sites offer great advantages in terms of payload performance, especially for the delivery to geostationary orbit. But in the 90's, while retaining these advantages for peak performance operations, equatorial launch sites will loose much of their present interest, in the case of routine space operations. Then, the low-thrust high-energy space tugs, that are now being developed or studied, will ferry payloads back and forth from any low earth orbit to geostationary orbit or any other orbit with energy and cost efficiency. The main activity of launch centers will be delivery of massive payloads in low Earth orbit. Almost any low Earth orbit will do, the convenience of the logistics will be determinant in the choice of the launching site.

Economically, if most of the French and European space ( transportation is done from a continental site, the drastic improvement of access conditions to the launch site, from any point in Europe, and the important reduction of ground transportation costs will more than offset the minor disadvantages of not being equatorial. The launch site will be efficiently connected by road and rail to all the major European development and production centers, within hours of reach rather than weeks. This is a necessary condition for the development of an industry of •'} mass-produced launchers with all the production cost reductions that ! would follow. It will offer tremendous growth opportunities f^r s»11 ; specp-related industrial located in Frinrp and in- Europe. - 237 -

Sociologically, a continental launch site would bring closer to the whole population the reality of space. All the technical activities related to the spaceport itself would be beneficial in terns of employement and skill development for the entire region around the site* And a major tourist industry could be built around the launchings and the activities of the center.

The Languedoc region, on the Mediterranean coast in the south of France, could offer such a site, with all the adequate operational and safety guarantiee. Major benefits could be derived not only for space exploration and development, but also for the French and the European society in general. - 238 -

IAA-83-244

"The Fruits of Space Exploitation! Cornucopia or Armageddon?" Dr. Robert M. Bowman Institute for Space and Security Studies

The paper makes the point that we are at a line crisis in the utilization of space. A crisis contains elements of both danger and opportunity, and the current situation certainly fits that description. On the one hand, we are on the verge of having the technology and resources to eliminate many of the great problems which have been plaguing mankind for centuries, including that of hunger. On the other hand, we seem to he bypassing these opportunities in a headlong rush into an arms race in space which could lead to the. destruction of all human life.

This paper makes the case that allowing the arms race to extend into space will greatly increase the danger of nuclear war by putting at risk satellite warning systems, creating a situation where accidental war is highly likely, and compounding the destabilizing fear caused by new nuclear weapons with first-strike capabilities.

In addition^ the weaponization of space would consume staggering amounts of money, brainpower, technology, and industrial capacity — resources which could otherwise be put to better use. It would also foreclose promising opportunities for East-West cooperation in joint space ventures for the benefit of the whole world, with the attendant hope for better understanding/ lessened tensions, and eventual elimination of the threat of war The paper will outline both the dangers and the opportunities. Considerable emphasis will be given to the effect of space systems on nuclear strategy and to the interaction between space weapons and the new generation n nuclear weapons with first-strike capabilities. Several scenarios will be presented which show how the presence of weapons in space could lead to accidental war or to one side or the other feeling forced into a preemptive strike. The paper will include a critical analysis of proposed space-based anti-ballistic missile systems whose proponents claim to offer assured survival as a substitute for Mutual Assured Destruction. Proponents claim that space-based defensive systems can be deployed: (1) using existing off-the-shelf technology, (2) at a reasonable (about $15 billion) cost, (3) within five to six years. They further claim that the systems can: (4) protect our people, (5) end the immorality of Mutual Assured Destruction (HAD), and (6) improve chances for arms control. None of these claims are true. The paper will present the facts relating to these six claims.

The paper will describe some specific opportunities which could be realized in a weapons-free space environment. Among them is an international peacekeeping system which could be based initially on the Soviet Salyut, the U.S. Shuttle, and the French SPOT. The participation of other nations such as China and India could provide balance in the organization overseeing such a peacekeeping system. It is anticipated that the system would eventually have its own dedicated sensor satellites and space platforms and take on additional missions of a civilian nature. The system could provide in the earth resources, weather monitoring, and oceanographic fields what Intelsat provides in communications — a global system for the solution of global problems. Maintaining the peace by providing international warning of threatening military activities is perhaps the most critical mission of an international space system. Hopefully, however, the present atmosphere of tension and fear will eventually be overcome by the very act of working together in such a system. Then, the system would be able to spend the majority of its time tracking sources of pollution, monitoring severe storms, assisting in search-and-rescue efforts, assessing the progress of efforts to reverse deforestation, helping discover new sources of scarce resources, providing guidance in crop management, and making the fruits of the information society available on a worldwide basis. - 240 - IAF-83-245 SOCIO-ECONOMICAL. EFFICIENCY OF COOPERATION IN REALIZATION OP INDUSTRIAL SPACE PROGRAMMS S.A.Sarkisian, S.S.Corunov, A.A.Gurov, I.I.Samoilova, M.M.Anufriev Interooamos consul, Academy Science USSR, 1983. One of the main advantages of apace vehicles in com- parison with traditional means need in aircraft is the po- ssibility to settle scientific and industrial tasks basins on an international scale with the highest degree of effi- cieny. There are a few branches where we get such an op- portunity: tasks of global communication, navigation, na- tural resources investigations of the Earth and ocean, the state of environment) meteorology• life-saving actions un- der space conditions, aviation, etc* Iα these branches me are getting not only opportunities but a rich experience of practice including international cooperation* While ha- ving defined the new trends and forms in this branch of space exploitation we are to consider the central criteria of costs lowering and the rise of socio-eoonomioal efficien- cy. It is important to take into consideration a very high level of space programme investmets and it is obvious that the use of all those space vehicles advantages only by a single country is unreasonable. There are many oonsumers of sputnlo information because the same information can fee interpreted in different ways. It influences muoh the in- crease of economical and sooial efficiency of investments ia space practice and precipitates the recoupment* On the other hand it gives the opportunity to attract some resou- rces, science technical achievments of international space programme participants. Under these conditions we can suo- oesfully settle the problems of space law, aid to the develo- ping oountries and other sooial tasks. This paper estimates all those realised programme of such type and forecasts all possible actions in this branch. Ref # IAA-83-246 TITLE: "Competition in Space: Government Versus Industry" AUTHOR: Paul D. Haley ORGANIZATION: Ford Aerospace and Communications Corporation Houston, Texas USA

ABSTRACT Attitudes toward allowing private companies to take on a competitive and aggressive role in meeting the needs of outer space users has changed drastically in the United States 1n the last 2 years. Launches of artifi- cial earth satellites Into Low Earth Orbit (LEO; and Geosynchronous Earth Orbit (6E0) have been the bastion of government for nearly 3 decades. With a number of major aerospace firms ready to venture Into operating their own expendable launch vehicles, the US government finally gave Its approval 1n May 1983 for them to take this important step ~ one which will enhance the competition process for a share 1n the highly profitable 6E0 market. Space Services of America, Inc. took the initial action In its well pub- licized private suborbital launch conducted In Texas 1n late 1982. Draw- Ing on a myriad of Inquiries and Investor interest, this small entrepeneur company is concentrating on low earth orbit satellite launches and market- ing to the military. The outcome of this event and Its ramifications are presented. The slowed pace of US Space Shuttle and European Arlane satellite deliveries to orbit has prompted demand to Increase more rapidly than expected wj£h the possibility that other International competitors may soon enter the arena. A descriptive overview of NASA and operations reveal Assets and liabilities which provides Insight Into key elements in providing a launch servicetnamely financing, throw weight,scheduling, user charges, and relia- bility. Comparison of projected costs per pound to GEO and weight capacity of current and proposed expendable and resusable launchers (Including upper stages) are illustrated for both the American and European systems. Also presented 1s a quick look at private Industry proposals to NASA and a review of some of the more active companies Involved in Independent launch operations. 1AA-B3-247

The GEO-SPAS Approach for Commercial Remote Sensing

II. Chr. Beni5hr and D.E. Koeile, MBB/FRNQ Spate Division, Oltobruim, FRG

The Sf'AS-01 reusable shuttle platform has been launched mi M:< Night No. / on 18. Juno 1983. Deployment intH« n successfully demoristrated. An essential element of the SPAS 01 payload consisted of a fully electronic remote sensing camera, i.e. the Modular Optoelectronic Multispettral Scanner (MOMS). Urn,. SPAS-01 may be considered as a prototype for future space -limn*? iai remote sensinq missions.

Ihe concept of a small Shuttle-drdicated spac.ee> art. with multiple re-uses allows to reduce the space segment cost to a mininmm, mw< ii lower than for any other (expendableJ spaciu-tfl: cun'.'ept. hirrhfi more, besides the current optical instrumentation other exisiUn.i payload elements such as, for example, a synthetic aperture ra (SAR) may also bo accommodated.

In combination with a multi-spectral scanner, covering selected channels in the visible and near infra-red (1.6gin and ^.>?yni), ami a broad band (visible) stereo-scanner of 10 to 20m resolution ;> wide range of specific requirements for the petrol and mininq in- dustry, as well as for cartography, can be fulfilled. Such a pavl". package could be supplemented by a SIR-type radar.

The current GEO-SPAS concept is characterized by short mission durations, i.e. weeks or months, and relatively short implements i•••••• periods. The mission characteristics and observation areas will bp defined according to the customer requirements. - 243 -

The most cost effective solution, however, possibly restricted in terms of data collected, is a shuttle sortie mission limited to 5-7 days. Such a mission could provide valuable data for about 40 Million km2 in total, assuming a coverage (useful data time) of about 7 percent during mission duration. Of course, details of actual coverage will depend on customer specifications and on final selection of orbit parameters.

A more advanced kind of mission would involve a SPAS Free-Flyer in order a achieve the~opt1mum results in terms of quality and quantity of data. This type of mission, however, would involve an extensive ground network and/or a data relay satellite like TDRSS.

The GEO-SPAS platform concept will be described as well as the MBB Multispectral MOMS camera including its next generation which will feature channels in the near infra-red and full-scale stereo ca- pability. Furthermore a comparative cost analysis for such missions will be given. - 244 - IAF-83-248 THE RISE OF ECONOMICAL EFFECTIVENESS CONNECTED WITH SPACE PROGRAMMS OF NATURAL RESOURCES INVESTIGATIONS S.S.Corunov, A*G*Gurov, V*F*Zalzeva, N.A.Milovanova, T.l.Gud- kova* Intercoemoa consul, Academy Science USSR, 1983. During the last ten years we have got experience of con- struction and exploitation or space means dealing with natural resources investigations (NRl), the recent level of astrona- utics and technology development lets to work out space sys- tems different in construction and parameters* In this case economical purposefulness is a decisive oondition while cho- osing one of the alternative ways connected with the deve- lopment of space technology* Ve define the space programme(NRl) as a realization of the complexe aimed at distance observations and measurement of natural resources with the help of specially prepared, ma- nufactured, operating spaoe system, which unites orbital and surface elements. It is possible to distinguish two independent fragments in the interpretation of space programme: 1) formation of programme devoted to the perfomance of •clence-teohnical economical measures dealing with the con- struction of space system elements; 2) realization of programme which provides measures con- nected with the exploitation of spaoe system and another task we are to achieve is the required enumeration of natural re- sources photography* The most important condition which unites both programme fragments is the choice of its economically optimal variant providing the observation and measurement of natural resources with maximum effectiveness* This report is devoted to the problems of economically optimal development of space programme (NRl) and their fore- casting* This paper says about the most important aspects of com- plex approach to the choioe of economically optimal variant closely connected with the space programme, including tasks of programme formation, means of its performing, required re- sources and sooio-economioal effect of its realization. The main context of the paper is the consideration of national, territorial and sectoral programme, it is also im- portant to consider the faotor of international cooperation in this sphere on oommeroial basis* The environmental Economics of Orbital Itebri;; Dean A. Olmstead - OTE Sprint

Various policies have been proposed for controlling l.he fiMwtli oi' man- made orbital debris. Jt is now time t<< b«'^!n u detailed evulnnlldii of the effectiveness and economic impacts of the proponed f>• 11 if i»>.<; aml nl1 the international organization formed to determine 'uid implement. nn approved policy. This paper first examines the tncremsinp ssafVty hazard of man-made orbital debris from an economic impnci- imrniiwi.i«>. Increased safety for future users of the orbit i;; l.ra'leii off against increased costs for today's users. Then an optimization model i;; pro- posed for determining the relative efficacy of Severn I d'-bri;; nbal pm>»rit policies and implementation mechanisms. The eeuirurii •••HI iy n policy is detennined for several differenf. market, nnd ti*i'lit scenarios. Finally, the impacts of other instifcutin?w I

Man-made orbital debris, though a hazard in all orbits, is of interest from the policy perspective at the geosynchronous altitude. This is due to the international interest in preserving this vnlunbl^ and limited resource for all countries i.noludirif? th'.-«e Lhdt. do not currently, but may at some time in the future, have the technology t- exploit those xinique attributes of the geostationary orbit which make it a particularly attractive location for roriuminlcatiori sKfellil-ep. Since the debris hazard Is increasing over time, t,he decisions mn-ir today relative to the use of the geostationary orbit wiU affect tli« availability of the resource to all future n«prs.

Examining man-made orbital debris as a pollutant of the orbital environ- ment is justified because debris is a joint product in Uie "production" of an information throughput, capability using satellites placed tn earth orbits. If the probability of collision with a particular "producer's" spacecraft were significantly influenced by the actions of that producei , the consequences of increasing the orbital debris population would bf accounted for in that producer's output decisions. But, since the prob- ability of a collision between debris and an active spacecraft has been viewed as insignificantly small and the marginal impact of any one pro- ducer even smaller, the current users of the orbit resource have not so incorporated the long-term impacts of the joint production of orbital debris. This increasing safety hazard creates n negative externality from the perspective of potential future orbit users. Several, policy options exist which can alter the impacts of this externality or rppmvf it altogether.

Policy options will be evaluated on the basis of the incentives created for producers to adopt pollution abatement pr-icHoes, tb^ degree to - 246 -

which the policy preserves the orbit resource J'or future uaers (i.e., th policy's effectiveness in attaining the established safety target), the acceptability of the policy to national administrations, and the hnpm:t of the policy on the cost of using the orbit resource as opposed t<> al- ternative technologies. The policy analysis is aided through the development of an optimization model that relates the growth in the debris population over time with the expenditures on debris abatement, the existing debris population, the rate of productive activity and the discount rate (the value placed on preserving the orbit for future users).

It is shown that the selection of an optimal policy is sensitive to the relative cost of alternative technologies. Debris abatement resultinr from the implementation of any of the policy options increases the use- ful "physical" lifetime of the geostationary orbit by reducing the safety hazard at any given time. But the cost of using the orbit re- source is increased in the near-term relative to other technologies which can provide a similar capability (e.g. optical fibers). In the longer-term, the adoption of debris abatement practices results in lower total costs than does no abatement. Hence, the adoption of debris abatement may or may not extend the "economic" lifetime of the nrbit depending on the values of several exogenous variables. Under different assumptions regarding the physical behavior of debris collisions in orbit, the orbit resource can be modelled either as a renewable or non-renewable resource. If the assumptions imply that the resource is renewable, a level of debris abatement can be shown to exist which provides for a steady-state equilibrium level of debris "produo • tion." On the other hand, if the resource is non-renewable and orbitnl debris is self-propagating, a time can be determined beyond which economic usefulness of the orbit resource will be diminished to irrespective of the level of debris abatement adopted. Clearly, simply determining the economically optimum policy vill not ensure its adoption, but the optimum will provide a benchmark for com- paring the additional costs of a less than optimal policy with any "institutional" benefits associated with the adoption of such a policy. For example, one institutional consideration is the possible conflict of views between the different services utilizing the geostationary orbit. If the satellite service providers face different threats from alternative technologies (e.g. optical fibers vs. fixed satellite ser vice; or cable television vs. broadcast satellite service), they imy prefer different debris control policies. Several extensions to the basic optimization model will be presented including relaxation of the homogeneous orbit assumption and the addition of uncertainty on future valuee and costs. The optimal policy's sensitivity to these modifications will alno be determined. - 24? -

IM-83-25^ Orbital Debris Management: International Cooperation for the Control of a Growing Safety Hazard Dean A. Olmstead - GTE Sprint Martin A. Rothblatt - University of Maryland

Various policies have been proposed for controlling the growth of man- made orbital debris. It is now time to begin a detailed evaluation of the effectiveness and economic impacts of the proposed policies, and to develop the legal framework for supporting an international organization formed to determine arifi implement an approved policy. This paper first examines the increasing safety hazard of man-made orbital debris from an economic impact perspective. Increased safety for future users of the orbit is traded off against increased costs for today's users. Then an optimization model is proposed for determining the relative efficacy of several debris abatement policies and implementation mech- anisms. The economically optimal policy is determined for several different market and technology scenarios. Finally, the impacts of other institutional considerations on the optimal policy selection are considered, and the implications of relevant existing bodies of law are analyzed.

Policy options will be evaluated on the basis of the incentives created for producers to adopt pollution abatement practices, the degree to which the policy preserves the orbit resource for future users (i.e., the policy's effectiveness in attaining the established safety target), the acceptability of the policy to national administrations, and the impact of the policy on the cost of using the orbit resource as opposed to alternative technologies. The policy analysis is aided through the development of an optimization model that relates the growth in the debris population over time with the expenditures on debris abatement, the existing debris population, the rate of productive activity and the discount rate (the "value" placed on preserving the orbit for future users).

It is shown that the selection of an optimal policy is sensitive to the relative cost of alternative technologies. Debris abatement resulting from the implementation of any of the policy options increases the use- ful "physical" lifetime of the geostationary orbit by reducing the safety hazard at any given time. But the cost of using the orbit resource is increased in the near-term relative to other technologies which can provide a similar capability (e.g. optical fibers). In the longer-term, the adoption of debris abatement practices results in lower total costs than does no abatement. Hence, the adoption of debris abatement may or may not extend the "economic" lifetime of the orbit depending on the values of several exogenous variables. - 248-

Under different assumptions regarding the physical behavior of debris collisions in orbit, the orbit resource can be modelled either as a renewable or non-rene*'^ole resource. If the assumptions imply that the resource is renewable, a level of debris abatement can be shown to exist, which provides for a steady-state equilibrium level of debris "production. On the other hand, if the resource is non-renewable and orbital debris is self-propagating, a tine can be determined beyond which the economic usefulness of the orbit resource will be diminished to zero, irrespec- tive' of the level of debris abatement adopted. Clearly, simply determining the economically optimum policy will not ensure its adoption, but the optimum will provide a benchmark for com- paring the additional costs of a less than optimal policy with any "institutional" benefits* associated with the adoption of such a policy. For example, a benefit not accounted for in the economic raodel is the political goodwill vhioh tbe countries utilizing space would gain with the developing countries by demonstrating concern for the future safety of the space environment. Another institutional consideration is the possible conflict of views between the different services utilizing the geostationary orbit. If the satellite service providers face different threats from alternative technologies (e.g. optical fibers vs. fixed satellite service; or cable television vs. broadcast satellite service), they may prefer different debris control policies. The effects of these, and other, institutional considerations on the selection of an optimal policy will be analyzed.

Vith regard to the legal framework for supporting an international organization to determine and implement an approved policy, considera- tion is given to existing competent organizations as well as to new foci of authority. It is shown that reliance on the ITU is most sensible in light of the organization's.universal membership, plenary aiithority in satellite communications and existing framework of rule-generating technical consultative committees. As to appropriate rules, analysis is made of pertinent provisions of the Convention on Registration of Space Objects, the Convention on Liability for Damage Caused by Objects Launched into Outer Space, and the Outer Space Treaty of 1067. The differential impact of these bodies of law upon the sovereign and Inter- national generation of space debris is explored in depth, &a are t»ie legal implications of the conclusions derived from the optimization model. - 249 -

IAA-CI-Z55 Safety of Space Activities

L. Perek Astronorr. J cal Institute, Czechoslovak Academy of Sciences, Prague

The necessity of adopting measures for the safety of space activities was mentioned at the Space Safety and Rescue Symposium last year. Such measures have to be adopted by international organizations/ in particular by the United Nations, on the basis of agreements reached nnong delegations to the UN Committee on the Peaceful Uses of Outer Space. Before the Comnittee can act, or even discuss such subjects in a neaningful way, the scientific and engineering community has to do the preparatory work and elaborate factual and technical bases. In the first place, principles for collision avoidance have to be devised, possibly in the forn. of traffic separat- ion schemes. There are specific orbital bells which are being used by various satellite systems or which would be convenient for one or other of the space applications. It is necessary to set up a list of such orbital belts and to investigate whether the collision probabilities would be reduced by their preferential or exclusive use for the particular application. Collision probabilities would bo further reduced by systematic removal of inactive satellites from orbital belts used for active systems. At low altitudes, the natural decay of satellites can be speeded up by suitable manoeuvres leading to the burning up of the satellites or to their iirpact on the earth in uninhabited regions or oceans. At high altitudes, removal into disposal orbits may be more economical. Some disposal orbits cr orbital belts are already being used. E.g., several satellites have been removed from the geostationary orbit into a region beyond, which Is not used tor active satellites and where the objects will stay inde- finitely without ever returning to the geostationary orbit, l.i another instance, satellites which performed their activit- ies in low orbits, have been moved up to altitudes of some 900 to 1000 km. from such orbits satellites will not return to the dense atmosphere before several hundred years. It is necessary to Investigate whether other orbital belts, at other altitudes, should be reserved to serve as disposal areas .either permanently or for a long but limited timespan. Small untrackable debris pose a grave danger to any active satellite they encounter because the speed of impact is, as a rule, very high and the damsge fetel. dorecver, cleaning up outer space by collecting small debris piece by piece is difficult and much more evpensive then any measures preventing the creation of debris. Recommendations should be elaborated to restrict as f*r as feasible the number of debris generated during launch or operation of a satellite. Also - 250 - explosions of spent rockets end fuel containers, wMrh are responsible for a ^considerable proportion of debris, stu>uld be prevented by a suitable design or operation. Although so«e of the measures are being implemented by launching agencies/ there are no International agreements or recommen- dations on the subject. Also standards for the quality of technical equipment and on the necessary competence of personnel are needed end will be even more necessary In the future when a proliferat- ion of launching agencies can be expected. One of the prerequisites for aplying the above safety measures Is the tinely knowledge of satellite movements. Information which is available at present through the United Nations or through non-governmental organizations is suffic- ient for maHng a general assessment of the number of space objects In individual parts of outer- space. It Is Irssuffici*ni for identifying an observed space object or for determining the position and speed of any space object at a given mon?nt. Detailed deta which are necessary for that purpose are being published only In national publications with t circulation. The scientific community should prepare how to wake such information readily available to all who could contribute to the safety of spare activities. - 251 -

IAA-83-257 SHUTTLE PAYLOAD SAFETY Charles Teleki ORI, INC., Silver Spring, MD, USA

The replacement of expendible launch vehicles with a retrievable, manned launch vehicle, the Space Shuttle, resulted In dramatic changes In the safety requirements Imposed on payloads. This paper discusses the safety requirements and safety assurance program applicable to payloads using the Space Shuttle. The requirements are designed to protect equipment and personnel exposed to the payload. They Include flight safety as well as ground safety, which are controlled by NASA's Johnson Space Center and Kennedy Space Center, respectively. These requirements Impact all phases of the production of the payload, Including the flight hardware, software and ground support equipment. They also affect the integration of the payload with the Shuttle and the ground and flight operations. The requirements Include a safety assessment review program conducted by NASA to monitor the payload safety activities. The cornerstone of the safety assurance program Is a properly formulated safety program plan dovetailed with NASA's safety review process. For efficient implementation, the plan must Insure timely consideration of the safety requirements throughout the payload development and verification phases. Also, It has to be tailored to suit the specific needs of the payload. A detailed discussion of the major elements of the safety program 1s presented; this Includes the Identification and control of hazards and the conduct of the formal safety assessment reviews. Specific requirements with major impact on the equipment design are highlighted and their Implementation 1s discussed. The paper stresses the importance of a successful safety program, I.e., one that Is acceptable to the cognizant NASA Centers, which 1s a prerequisite for allowing a payload to fly on the Shuttle. IAA-83-2S9 SPACE SHUTTLE SAFETY REPORT — THE FIRST SEVEN MISSIONS Nelson E. Brown and Jeri W. Brown Lyndon B. Johnson Space Center National Aeronautics and Space Administration Houston, Texas I). S. A. By mid-1983 seven Space Shuttle missions have been flown hy the United States, with 21 astronauts and various international carqo elements launched into earth orbit. The first four flights (SIS-1 through 4) were classified as test flights by NASA and designed lo collect performance data on the Space Transportation System (STS). The latter three flights (STS-5, 6, and 7) transported both payloads that remained attached to the Shuttle Orbiter and international communications satellites with upper stages that were deployed by the Orbiter for insertion into geosynchronous orbits. Precluding unforeseen major problems, by mid-1984 some 10 to 12 additional launches will he completed with about 50 astronauts participating. In future years, the STS flight rate will reach or exceed 24 annually with astronaut/c»ewmeinber participation in the 100-120 range. As in the development of any complex aerospace program, problems and anomalies have appeared in the Shuttle Program thus far. On a flight-by-flight basis, each problem area is recorded and its resolution tracked and documented through completion. Problems and anomalies with potential safety implications for astronauts, ground crews, ami populations, STS components, and payloads are resolved prior to the next flight. Non-safety critical problems are normally resolved prior to the next flight but, depending on operational criticality, can be delayed to later flights to avoid impacting payload manifesting and mission schedules. Problems have occurred across several STS subsystems at various criticality levels. For example, on STS-1 a somewhat minor problem in the Orbiter flight software timing sequence between primary and backup computer operation resulted in a two-day launch delay. The computers control Orbiter operations. On STS-2, an out-of-tolerance lubricating oil pressure measurement on Orbiter auxiliary power units (APU) numbers I and 3 caused by clogged filters resulted in delaying the launch eight days. The auxiliary power units provide hydraulic power to drive the orbiter aerosurfaces, main engine control valves and gimnle actuators, the brakes, nose wheel steering and landing gear deployment. Also, the planned 5-day STS-2 mission was reduced to 2 days-6 hours due to an on-orb1t failure 1n one of the three Orbiter fuel cells that provide electrical power throughout the vehicle. - 253 -

In the flight of STS-3, during Orbiter tail-to-sun attitude, the payload bay doors jammed before fully closing on the first attempt but closed on subsequent testing operations. The probable cause suggested a foreign object jamming the latching mechanism. Also, the wrist TV camera on the Remote Manipulator System (RMS) malfunctioned due to an electrical short inside the camera power supply, thereby compromising the acquisition of RMS dynamic test data. Landing of STS-3 was extended one day due to wet lakebed runway conditions at the primary landing site. On STS-4, as during several other flights, various anomalies and/or malfunctions were recorded in the APU and fuel celt systems, sudi as oil pressure, leakage, temperature, and heater operation. The Solid Rocket Boosters on STS-4 were destroyed on water impact due to malfunctions in the parachute deployment system. STS-5 crewmembers encountered problems with the extravehicular mobility units (EMU-integrated spacesuU and life support system) causing cancellation of the first Shuttle space walk. Inflight attempts to repair the EMU's were unsuccessful. Cathode ray tube (CRT) number 2 went blank 30 minutes into the STS-5 flight. Inflight maintenance was successful in restoring the CRT operations. The STS-6 mission was postponed due to a hydrogen leak in the Orbiter's aft compartment. The leak developed from a crack in a cooling tube in one of the three main engine nozzles. During asceit, a CCTV monitor bracket at the aft flight deck station debonded from the bulkhead. During STS-7, one of the Orbiter windows was pitted by a meteoroid. Approximately 375 off-nominal conditions/problems have been recorded through the flight of STS-7. Many of the off-nominal conditions were one-time, non-generic component malfunctions warranting only adjustment or repair/replacement. Others presented conditions that required real-time action to avoid compromising crew and equipment safety. Excluding the loss of two solid rocket boosters, all problems were resolved while limiting hazardous conditions to personnel and equipment within the program design guidelines. This paper summarizes a review of all documented problems, anomalies, malfunctions, etc. for the first 7 STS flights. Those problems having direct safety implications are identified and categorized with respect to personnel (flight and ground crewmembers), vehicle, and payloads/experiments. These problems are discussed with respect to their immediate (e.g., inflight repair) and/or long-term (e.g., system redesign) solutions. Based on the initial flight experience (STS l>7), trends that could cause hazardous conditions for future missions are identified. Special emphasis Is placed on international cooperation among vehicle) payload, and experiment engineers, designers, planners, and crews to ensure future program safety for both Space Shuttle operations and Space Station planning and implementation. IAA-83-261 "EMERGENCY COMMUNICATIONS VIA SATELLITE"

A.E. Winter, Director Earth Station Engineering Telesat Canada 333 River Road Ottawa, Ontario, CANADA

Vast areas of the world do not presently have communication.*; facilities in place. With the increase in travel, resourot? exploration, and economic development globally, there are increasing requirements for communications systems that can be used in temporary situations for emergencies or disasters or for work assignments in remote areas. Satellite communi- cations systems are, in concept, ideally suited to meet such requirements but the development of small, portable earth stations for global use has been limited by the available technology, frequency allocations, satellite design parameters and institutional boundaries. The paper reviews the voice, data and image communication requirements for emergency use in such areas as medical treatment, disaster response, emet 'inm- measures, search and rescue and resource development, both within and outside Canada. The development of satellite communications systems such as INTELSAT and associated earth station designs are describnd in the paper, with a review of new and proposed satellite systems including the US/Canadian MSAT at 800 MHz, the European ECS and the Canadian Anik C at 14/12 GHz, and the Japanese CS series at 10/20 GHz, which may be more suited to small and mobile earth station designs. in addition, the advantages and disadvantages of satellite systems with dedicated emergency communication features such as the MARECS L-band channel and the SARSAT demonstration system are- listed. Finally, a review of institutional issues to be resolved for efficient and practical emergency communications via satellite such as transborder communications and interna- tional search and rescue agreements are summarized in the paper. - 255 -

COSJfAS-SARSAT SYSTEM El'FIClKJICY .V.TTH THE "CJSMG3-J3U3"AnD"1447" SATJSLlilTEJ W ORRIT Y. Atacrov, A* Palaaliov, It. Chornyar-v, I., ic.hnl.yakov, Y. Zarabov

V-U MOKSVIAZSIUTIJIK, Moirow, USSR Since the Soviet "Oo3n>oa-Jjt.iJ" and "Oo3n'oa-I44Y" satel- lites wore put into near-pola?* orbits, TuOO k;a height, on 30 June 1982 and 24 Kajrch T'jb.3, oxte»isivo loatin^ and use of the COSiAS-SARSAT. polar-orbiting ayatom co\uiiimced. The system has boen developed, starting From Ty77, ae-n joint satellite-aided search and roacuo project by the USSR (C03PAS mission) and USA, Canada and Fr«mce (JAHSAT piiflni- on). Testa conducted after launcb.in;- tlir "Cofjnog-JJbi" and "00817103-1447" satellites prove ihut t!ie Cv)V!i A3-SARSA1 ayatem meets all T.MO requireiaenta to tlie polur-orbitinr; eubayatema in the PGLiDSo, Due to r;l.obal oovor-'^o, prompt aervicts, reliable distronrt alcrtinij and accurate poeition .location, the syatein allows *i drastic dur.roaae (by L'O-'JO hours) of an average duration of 3AR opea-alions, thcroby permitting to reduce a probability of human and ^ooda loasca and environmental pollution in f\i α^rnnn incidents, aa well as costs of SAR operations. Hased upon the known average distress frequency rate, it can bo nxporfced with confidence that the total coat Leaaea proven hod due to the use of the syatem in I9G4-I994 '"ill be fnv in oxoeaa of the expenditure needed for ita arrangement and operation. To a certain extent, it depends upon the rate of fitting ships and aircraft with 406 MHz fiflRBn which allow posi- tioning accuracy in the order of 3 km and transmit their identity and data on distress coordinates, time and nature of distress. It is assumed that the 406 Mils EriRBa will be much in demand due to low cost and hihg efficiency. Widely uoed at an early stage will bo the cxiatin/j 121.5 MHz EPIRBs (200 thousand at pi-eernt). Their utili- ty was prowed in recent incidents when the EilitPfi* transmissions were relayed, by the "Co9nio8--Ij;!j" e.'»t«llt- te thus contributing to rapid rnscue of survivors from distressed vehicles. - 256 - IAF-8J-27I DEVELOPMENT KE'5UJ.AHI?J.E3 OP KXTRATEKRIJSTHTAJ.I JriTBI.J.JtlEN!?? AND THE SEARCH STRATEGY V.S. Troitskij Intercosmos Council, IFS3R Academy of ScJennfS There are theoretical statements on the p of extraterrestrial intelligents (El) which av» bound on fche assumptions on the persistence of Uio life pm^r/fonne in the Universe (Drake), on unlimited pospibJlS ties of th the energy production (Kardashev), on the inevitably prr> pagation of the earlier developed civilizations in all the Galaxy (Hart). Conclusions from these statements are in a sharp con- trast with the experiment which is in the assertion on the absence of EI in general and the singularity of th« Earth civilization (ShklovskiJ) or in the assertion on the early ruin of civilisations* The paper suggests other theoretical conceptions of EI development .regularities. A hypothesis Iβ consi'loroil on the life origin only at a definite phase of the Uni- verse evolution almost simultaneously everywhere on sui- table planets, hence, as on the Earth about four milli- ard years ago. Possibilities aro considered of the civilization energy product under the condition of the energy product limitation by the demand of concervation and keeping up the inhabited medium in the given biologically specified temperature conditions* Consequences of new assumption are discussed* The upper boundary of the energy product is proved to be equal to the order of one thousandth of the star energy product* The energetic principle :is eurc- geated for the choice of the communication wave and nip- nalizatlon* - 357 -

-P1-373 Use of Cosmic Interactions for Benefit of Mankind T.K.Wiesenber^er Charles University of Prague, Czechoslovakia

This paper tries to tackle the possible use of cosmic in- teract ions for benefit of mankind. Fron this task it follows, that its first part deals with the notion of interaction in general and so&e of its categories. The second onn ntrivea to ox plain tlie character of out^r epuce or cosnic inUrac ' ir>n# Thy last one limits iteelf to the possible bemfitn for man- kind gained by thffe cosmic interactions, whoc»e main part rosy be realised b,y the CETT or 3E?I pro^rnm. T\/' abntrrc' of thin papor t! ere fore lies the following content. i.'.xplf notion of the notion of interaction in fi"nBr8l. Its re- cipi'Ocal function between two or more elements by which they &re effected. Ite WE in estepories ere based on the cybernetic, physico'-i biological, ecological, ps.vcholog.lcnl oi- sociologi- cal ana outer space /cosmic/ vievpoints. fJ«nnrnl chs»rficteriflticfl of cybernetic interaction. Characteristics nnd y-nrioup kind? of physical interaction* "^iff^rent cnte«nri-«s of biolo.'cfcnl in- teractions and their raoin features. Description of ecolo.»ic«l intorpction and explanation of its mnin function. ThieT elem^ntp of psychological and sociological intprnctionr en

The di.fforent enteroriep of coProic *n* rv^T or fJETt in- - 258 -

teroctionf. Their active end pssrive kinds and their physi- cal, biological and other characters. Two si^es of the c'->s- Kic interaction. The poccib-le future evolution of the cos- mic or outer epece interections. Influence of cosmic interaction on the tenefit of ninn- kind» Possible positive end negative influence of the cot-rsie interaction* JThcracter of positive end negetive €>ffecta of this interaction. The present rituotion pnd the probable e- volution of our civilization. The neceapnry chf.ngee in its present character for the further human development, yrelPcre end survival. The benefits of the cosmic interaction »n

IAF-33-274 "Popular Support for the Search for ExtraTerretrial Intelligence" Stan Kent and Dale Ubil Delta Vee, Inc.

SETI. the search for extraterrestrial intelligence, is often perteived as a large scale effort of the tvpe to be afforded only by national governments nr multi-national superstructures. Yet this subject is one that fascinates the individual citizen' in many cases the individual would willinqly join or support the search if there were a means of becoming involved. The media is acutely aware of this fascination and has profitably provided one channel for pseudo-involvement via science fiction, fantasy and more recently, journalistic coverage of scientists engaged in doing the science of SETI. But are there other channels for rejU individual support of and involvement in SETI7 These questions was asked in earnest in the United States when funds for SETI research were eliminated from NASA's 1982 budget.

The few months that NASA's SETI program was in danger saw many novel schemes hatched to continue SETI research. Now that NASA's program is alive again many of these ideas take on a new significance as they form a diverse complementary effort to NASA's program. For example, the SETI community has now been considerably broadened by averaqe radio amateurs with microcomputer capability participating in searching the Cosmic Haystack in areas currently unsearchable by NASA SETI equipment. Under the banner of Delta Vee. Inc., a non-profit space research and education corporation, radio amateurs, home computer enthusiasts, students, and NASA SETI scientists have been developing a prototype Amateur SETI (AMSETI) system. Using donated funds raised through its ExtraTer res trial Connection Fund. Delta Vee has been funding a series of workshops that have led to the design, development, and operation of an AMSETI station. Delta Vee plans to distribute the technical knowledge and prototype plans of this system to radio amateurs around the World in an effort designed to create a diverse complementary program to NASA's SETI endeavors. In doing so, Delta Vee hopes to eventually generate a broad-based SETI community that allows the average person with the tools of modern technological life the ability to participate in the greatest search of all time. This paper describes the technical basis and innovations that have made it possible for AMSETI to be taken seriously, Search strateaies for amateurs will be described, and examples of several existing and soon to be operational AMSETI systems will be given. The future of AMSETI will be considered in light of the unlimited ingenuity of radio amateurs and technological innovations that will allow greater search sensitivity and even the possibility of AMSETI beacons designed to - 260 -

announce our presence* Indeed* it may be a fundamental signature of the dawnino of technological intelligence when it becomes feasible for many discretei relatively low power beacons.to be deployed* Such reasoning has not been factored into traditional SETI search strategies yet calculations indicate that an A'recibo-size dish !0.8 light-years distant from Earth could detect a 10.25 GHZ 500 Watt AMBETI beacon in approximately 9.6 days of continuous integration *

As more and more radio amateurs and computer "hackers" Are encompassed into the SETI field many new approaches will be tried and many will fail* Even though the odds against success are great, the challenge will inspire many enthusiasts to try, and in doing so SETI will gain considerable papular support, Little did Steven Spielberg know when he had ET build an AMSETI station from spare parts to "phone home" that in less than a year many human beings would be doing the same thing with much the same motive that moves SETI researchers both amateur and professional alike..."Are we alone?" - 261 -

IAA-83-275

Sea-floor Hot Springs, Dissipative Structure* and the Creation of Living Organisms on Earth-1ike PIanets

John B. CdrlisB 428 SW 10th St., #2 Corvallis, Oregon 97333 USA

A new and elegant scientific hypothesis proposes that the deep sea hot springs which cooled the Earth's first ocean crust as it formed provided an environment which created self-replicating organic-structures and nurtured them as they evolved into our most ancient ancestors, the first living organisms on Earth. 'If the hypothesis is correct, it allows us to refine the criteria for planets in the Universe which exhibit life. The hypothesis draws, together in a web of reasoning a diverse set of observations and speculations from planetology, geology, chemistry, biology and thermodynamics: (1) A flow of matter and energy is required to create order in a second law of thermodynamics universe. There are spaces in the universe, called dissipative structures, as defined by I-lya' Prlgogine, through which there is a flow of matter and energy which drives them far from equilibrium and creates an ordered relationship among their chemical constituents. Free energy and reactants flow in, entropy, and-reaction products flow out. The appearence of autocatalytic and cross-catalytic reactions in this mnviranmont can lead to the creation of self-organizing entities. Our universe is characterized by the flow of energy outward from centers of gravitational accretion. This flow creates a heirachical system of interacting dissipative structures associated with these bodies. - 262 -

(2) The thermodynamic characteristics of these hot. springs which allowed them to "learn" how to create living organisms have interesting parallels with Gregory Bateson's "criteria α-f mental process" and his heirarchy of learning. These systems are driven to increasingly ordered steady states by the amplification of fluctuations which are normally damped. These steps can be considered as examples of learning. (3) On Earth, this heirarchical system consists of a pattern of convective heat transfer which drives the plate tectonic evolution of the crust and focuses the energy flow.' Submarine hot springs, a key element in this heirarchy, were created on the floors of the first oceans on Earth as they farmed during the last stages of accretion- nearly 4 . billion years ago. The geologic record of this period, the Archean* is dominated by granite-greenstone belts. These contain abundant submarine volcanic rocks and chemical sediments which precipitated from the hot springs associated with the volcanism. These hot springs, then as now, quench the magma which erupts along sea floor spreading centers to form new oceanic crust. One-fourth of all the heat escaping from the earth today flows through these hot springs; the total flux must have been considerably higher in the Archean.

(4) Within these hot springs, seawater is heated to temperatures approaching 600 degrees eelsius at a cracking front along the margin of the magma body deep within the permeable ocean crust. Seawater/rock reactions produce acid, reducing solutions containing reduced gases (methane, ammonia, hydrogen sulfide, carbon monoxide, hydrogen}, reduced transition metals and other interesting components, and line the rock fractures with catalytic clay minerals. These solutions rise through these fractures in the crust under the influence of bouyant forces mixing and reacting with cold oxidized sea water producing a mixing gradient of composition and temperature. These systems are potent and powerful continuous-flow chemical reactors; beautiful natural examples of dissipative structures. (5) On the prebiotic earth, these hot springs were the site .of reactions between oxygen produced by the photolysis of water by solar radiation in the upper - 263 -

atmosphere and the ferrous iron in the magma erupting -from the mantle to form the ocean crust* The balance of these two fluxes determined the oxidation state of the oceans and atmosphere. Archean greenstone belt chemical sediments are dominantly silica, oxides (iron oxide), carbonates and sulfates (barite and anhydrite). The oxidized nature of these sediments clearly indicates that the Archean ocean and atmosphere and were oxidized: they are. precisely those which would be precipitated from modern hot spring fluids injected into a prebiotic ocean with oxidative capacity. The hot spring plumes can be considered as flames of reduced fluids burning in an oxidizing environment.

(6) Most of the degassing of the earth took place by transfer of matter from ocean crust magmas through hot springs. Present data suggest that primordial carbon, as carbon dioxide, is extracted from the magma and discharged today from these springs at a rate which would produce the entire crustal reservoir of carbon in approximately 2.6 billion years. ( Considerable recycling' by subduction of deep sea sediments occurs). The range of isotopic fractionation of carbon between reduced and carbonate carbon in these Archean hat spring sediments is comparable to that expected from inorganic reduction of carbon dioxide in hot springs. The isotopic composition of carbon from hot spring vent animals and in coexisting methane and carbon dioxide in samples from modern hot springs fluids fall within this range. Thus it is not necessary to hypothesize photosynthesis in the early Archean to account for the fractionation observed in Archean rocks.

(7) Modern sea floor hot springs are inhabited by animal communities which are the first known to derive their entire primary productivity from chemosynthesis rather than photasynthesi5. The dynamic mixing of oxidized seawater species with the reduced components" of hydrothermal fluids provides numerous oxidation-reduction reactions which are utilized by a suite of chemosynthetic microorganisms for energy. this environment is also highly suitable -for the initial evolution of these chemosynthetic metabolic pathways. It is reasonable that the organisms which formed the bacterial mats commonly fossilized as stromatolites were initial ly .chemosynt.net ic rather than photosynthetic, and that photosynthesis - 264 -

evolved on the fringes of shallow water hot spring communities. lBY Living organisms arm self-replieating dlssipative structures.. The cell Iβ the -fundamental unit o-F life,, a Spice bounded by a membrane which creates a separate environment in which the reactions necessary for life can occur. These reactions involve the flow of free energy and reactahts into the cell, entropy and products out of the cell, *nd autocataiytic and cross catalytic reactions within the cell. <9> It is hypothesized that the sequence of chemical reactions required to convert simple inorganic compounds into organic replicating structures < protocells > capable of evolving into living organisms can occur along the miKing gradient within these hot springs. Although experimental abiotic synthesis in open systems simulating sea floor hot spring conditions has not been reported, the available data suggests that the precursere of the neces&ary macromolecules can be synthesized in these natural reactors. Organized structures with the capability of growing and budding or splitting have been synthesized from amino acids under hot spring conditions in closed systems. (10) The evolution of such structures into living organisms could, hypothetical ly, occur by nature?, selection. If thcise structures grow by transfer of matter from outside, and their reproduction rate is a function of their growth rate, and autocataiytic reactions occur within them which iherease their growth rate, then efficient autocataiytic cycles will be selected> (11) Archean greenstone belt hot spring sediments commonly contain a reduced carbon facies consisting of small round structures. These ere likely, in most cases, to be analogs of the non-living organic microstructures produced under hot spring conditions in the laboratory. However, in several Archean rock series, including the Onverwacht of South Africa and the Warrawoona in Australia, some of these structures have been described by paleontologists, on the basis of their morphology, «e fossils of living organisms. - 265 -

IAP-83-28I GkUXX "BELT OP LIPS" L.3. Marschnik, L*M, Mukhln Space Research Institute, USSR Academy of Science* The hypothesis *•• being substantiated according t# which technological civilizations of our type can origi- nate in Galaxy in 'belt of life' which Iβ a narrow zone including the Sun galactic orbit* Thie swie is under spe- cial conditions ae the c»xotati«n circle, which la an ejc- ceptianal region of Galaxy, passes through it. Birth and death of civilizatione should apparently occur in spiral arms because of supernova explosions. In this case life- time of civilizations is the time of its motion along the galactic orbit between neighbouring spiral arms. 3«3*ICr years are left to our civilisation up to the en- try the Perseus arm* In the Galaxy the ratio between a probable number of civilizations more developed and the number of civilizations less developed than our is of the order of 0*7* - 266 -

IAA-83-283

THE RATE OF COSMIC DISCOVERIES AND THE INFLUENCE OF ETI ON IT

I. Almar Konkoly Observatory Budapest XII. Box 67. Hungary 1525

A new class of cosmic phenomena, as defined by M. Harwit, is a class of astronomical objects or events that drasti- cally differs from all other classes /for exact definition see [13 /. After statistical reasoning Harwit has come to the conclusion that the discovery rate of new cosmic phenomena is now near to maximum and the search is approaching ccnpietion rather soon. In the future "multi- modal" phenomena will become redundantly recognized through a variety of independent techniques. He takes ETI into consideration only as one of the cosmic pheno- mena awaiting discovery /like black holes/ and SETI only as one of the search modes that can incidentally lead to the discovery of new natural cosmic phenomena.

The existence of ETI, or to be more precise the techno- logy of advanced extraterrestrial civilizations can however interfere with the logical syllogism of Harwit. If there are technical civilizations everywhere in the universe capable of large scale modifications of nature /as human civilization does it on Earth/ then the total number of different classes of cosmic phenomena increases. On the other hand, if we observe an abundant variety of different cosmic phenomena, exceeding the moderate numbers predicted by Harwit, it would be challenging to accept that the influence of technological intelli- gence modified a large enough quantity of natural celestial objects /asteroids, stars, galaxies etc./ considerably. Even if it were impossible to decide which of the newly discovered phenomena is a result.of engineering by ETI /e.g. Dyson spheres/ their total number would be an indicator of the share of intelligent activity in the universe. Since artificial phenomena might exist even after the disappearance of its creator, the simultaneity of civilizations is no longer an essential requirement. If the total number of different cosmic phenomena proves to be limited /a few hundred/ then the influence of ETI on the universe would be - 267 -

really negligible. My second remark is that CETI itself might help to discover new cosmic phenomena because it represents a new kind of information channel. This is one of the most exciting possibilities of CETI for astronomy. If sometimes in the future it proves to be feasible then it would open new horizons in the real sense of the word, transmitting information on phenomena which is never attainable from the Earth by means of the' usual carriers of information /radiation etc./.

The paper would like to direct attention to such an . uncommon but possible approach to the problem of the total number of active technological civilizations in the universe.

Reference: [_lj M. Harwit: Cosmic Discovery, Basic Books, Inc. 19B1 - 268 -

IAA-83-284 The Mass, time and energy characteristics of interstellar !flights during the long proper time of the astronauts /small acceleration/

M. Subotowicz Polish Astronautical Society in Warsaw and Department of the Experimental Physics, Institute of Physics* University M. Curie-Sklodowska in Lublin, Poland

The existence of the (extraterrestrial ^Intelligence (ETI) and extraterrestrial scientific-technical civilize- tions (STc) is of principol importance for CETI. According to Kardashev and Bracewell the Earth-like STC in their far- ther development can expand to the nearby planetary systems of the Galaxy, creating galactic community (Bracewell's galactic club) . In my previous paper (Subotowicz, 1982) the possibi- lities of the one-step rocket relativistic interstellar flight during the proper time of life of one-two generat- ions of astronauts were analysed* The realization of such interstellar flights is very improbable, not only in the ca- se of the advanced flights (to the center of our Milky Way, galaxy Andromeda or to the frontiers of the visibility of the largest optical telescopes) but also even to the nearest stars. The above results could be true for the case of the comparatively short proper time of flight of astronauts, it means - the case of the comparatively large acceleration. In the present paper are analysed relatlvistlc flights performed during the comparatively long proper time of as- tronauts, it means- the case of the email or very small ac- celeration. These flights to the nearest and very distant stars are realized during the life-tine of many generations with small and very small acceleration. There are calculated - 269 - proper tiaiee In the reference eystsas connected with the astronauts ( S^) and in the Inertlal reference systems ( velocities in S-, mass rations and energies for various flights* exhauat velocities and accelerations. Results will be critically discussed.

M. Subotowicz (l982) t "Can Kardaahev - type civilizations exist?", preprint 1AA-82-271 of the 33-rd IAF Congress in t>erla, Sept. 27-Oct. 2, 1982. - 270 -

О НЕКОТОРЫХ ХАРАКТЕРНЫХ ЧЕРТАХ СОВЕТСКОЙ ШКОЛЫ РАКЕТОСТРОЕНИЯ (1933-1937 гг.) И.А.Меркулов Советское национальное объединение историков естествознания и техники АН СССР, Москва В докладе отмечается, что проектирование жидкостных ракетных двигателей (ЖРД) и их экспериментальные исследо- вания в СССР начались в 1929 г., и что первые советские ЖРД, изготовленные в Газодинамической лаборатории (ГДЛ) в г.Ленинграде по проекту инженера В.И.Глушко, прошли огне- вые стендовые испытания в 1931 г. В докладе показывается, что годом рождения советско- го жидкостного ракетостроения следует считать 1933 г., когда состоялись запуски ракет "ГИРД-09" и "ГИРД-10". Да- лее призодятся сведения о 24 конструкциях ракет, постро- енных" в СССР в период с 1933 по 1940 гг. и описываются характерные черты советской школы ракетостроения, в числе которых отмечаются: - широкий охват проблемы ракетостроения, благодаря чему уже в 30-х годах в СССР были созданы ракеты многих типов, баллистические и крылатые, одноступенчатые и двух- ступенчатые, стартующие с земли и с самолета; - использование при проектировании ракет всех дости- жений авиационной науки, благодаря чему ракеты имели хо- рошие аэродинамические формы, легкую и вместе с тем проч- ную конструкцию, характерную для самолетов; - очень серьезное внимание к вопросам надежности жидкостных ракетных двигателей и ракет, что позволило создать еще в середине 30-х годов двигатели (ОРМ-65) и ракеты ("Осоавиахим", Р-03), успешно прошедшие испытания, в процессе которых была подтверждена их высокая надеж- ность; - большое внимание вопросам осуществления в будущем полетов в космос, вследствие чего ими уделялось серьезное внимание выбору наиболее эффективного топлива и получению высокого удельного импульса; - проведение одновременно с постройкой и испытаниями баллистических ракет работ по установке реактивных двига- телей на самолетах, причем эти работы успешно продолжались и в 40-х годах. В докладе подчеркивается, что благодаря широкому раз- витию работ по ракетной технике в СССР выросли кадры высо- коквалифицированных специалистов и был накоплен большой опыт по созданию ЙРД и ракетных летательных аппаратов. На основе анализа истории советского ракетостроения в докладе аргументируется вывод, что проведенная в СССР - 271 -

многолетняя работа в области жидкостного ракетостроения явилась одним из главных факторов, позволивших советским ученым и конструкторам создать двухступенчатую космиче- скую ракету "Спутник", которая вывела 4 октября 1957 го- да на околоземную орбиту первый в истории искусственный спутник Земли. - 272 -

IAA-83-289 THE REACTION MOTORS DIVISION THIOKOL (CHEMICAL) CORPORATION Frederick I. Ordway Alabama Space and Rocket Center Huntsville, Alabama, U.S.A. Prank Winter National Air and Space Museum Smithsonian Institution, Washington, D.C., U.S.A.

This paper represents the completion of a survey of Reaction Motors. The company's history as a corporate entity from late 1941 to early 1958 was presented at the 16th IAA Symposium on the History of Astronautics, Paris, September 1982. Now, in this paper, the Reaction Motors story is continued from the period 1 May 1958 when it became a division under the Thiokol Chemical Corporation (later Thiokol Corporation) to its demise over a decade later. Following a review of the administrative history of the Reaction Motors Division, the principal projects undertaken by the division are covered. These include factory-fueled, storable liquid-propellant rocket engines for Sparrow III and Bullpups A and B; an advanced storable liquid engine for the Condor air-to-surface missile; the storable liquid turbopump-fed engine for the Corvus air-to-air missile; the LR99 powerplant for the X-15 high-altitude, high- speed research aircraft; and vernier rockets for the Surveyor lunar soft landing craft, other RMD activities include

The part of Romanian Inventor ALEXANORU CIURCU ' in the Development of Theoretical and Practical Aspects of Reactive Motion in XIX—th Century.

F.Zaganescux R.Burlacuxx I,M.$tefanxxx

The main conception and technical achievements, developed both in Romania and France by the Romanian Inventor Alexandra Ciurcu (1854 - 1922) aided by Frenchman Just Buisson concerning a very interesting and original "Jet Propulsion Engine" are presented. Built, instaled and tested - on a small boat and on a litle railway rover - in Paris in the period 1886 - 1887, Ciurcu and Buisson's "Jet Propulsion Engine", was pattented under the french title "Le Propulseur a reaction" with No.l79ool/12 October 1886 by the Ministry of Commerce and Industry of the Republic of France and, later, in Germany, United Kingdom, Belgium, Italy and United States. This patent was discovered and commented by Romanian scientist-writer I.M.Stefan aided by Frenchman Guy Buisson, just in 1982, both Romanians ZagSnescu and Stefan being in touch concerning comments on Ciurcu's life and achievements. x Professor, dr.inaerodynamics: scientif. secretary. . Romanian Commission on astronautics, Academy of Romania xx M.S. in chemistry; sclent, researcher, ICITPR, Romania xxx ScientistTwriter., specialist in the History of Science and Technics; Bucharest, Romania - 274 -

IAA-83-291

A STUDY OF EARLY KOREAN R0CKETS(1377-1600)

Chae, Yeon Seok

Dept. Aerospace Eng., Miss. Stace University( U.S.A.)

This paper is a study of early Korean rockets, including details of the structure of Korean military rockets and rocket launcher used in the period around 1448. This information was obtained from the "Kuk-Cko-OfLZ-SoAye." (Introductory Remarks on National Rituals) published in 1474 and the "Cho-Son-^ang-Cho-SiZok"(Authentic Record on National Rituals) which will be discussed. The former was a very detailed de- scription of all firearms that were developed between 1448-1452. Drawings were made from the description of the "Firearms Illustration" to reproduce all of them. Some of the firearms were constructed from these plans and fired in January 1981. Koreans learned to make firearms and black powder from China before 1377. The first Korean rocket was called tumninQ-&4Jie.[jU-liu)a) which used between 1377-1447. In 1448, it was replaced with maglcat- macru.nt-OMA.OW(rocket propelled arrow). This rocket was built in 4 sizes 6nutU.,mzdium, lange. and muZtAptz-bombZe£-moLgicc£-mach£ne.-a>iriou)< The tcUigz-magicaZ-mchine.-a/Uuw1 e cylindrical paper propellent case was 70 cm long, 9.5 cm in exterior diameter. It was attached to a 5.3 m (17.4 ft) bamboo guiding stick. Warhead or explosive was attached to

Graduate student - 275 -

the head of the propellant case. It ie believed to have had a range of about 1500 m< 4900-6500 ft ). Medium and inatt-maglcaZ-machint-tVifims were launched from the multiple rocket launchur of £6%e-C

Mieczyslaw Subotowicz Polish Astronautical Society in Warsaw and Institute of Hiysics, University M. Curie-Sklodowska in Lublin, Poland

Born in Toruri 3.IV.1922 dr Olgierd Woiczek died in August, 24, 1982 in Warsaw. From 1971 he edided the scien- tific-popular Polish bimonthly "Astronautyka" and also from 1973 - the ».;-.< itific journal of the Polish Astronau- tical Society /PK~ ' "Postepy Astronautyki" /Progresses in Astronautics/. Mβ was one of the founders of PAS /1954/, then its General Secretary for 10 years and later - the deputy of the President of PAS for 15 years. Hβ was very active also in the field of the scientific research in astronautics and space physics. The scope and width of his knowledge can be seen in his 22 books and 34 papers in astronautics and space physics* 10 books and 14 papers in nuclear physics and other subjects. He published also several hundreds papers in popular journals, and took part several hundreds tiroes in radio and television program- me?. Hie PhO-degree /1963/ was based on his research in nuc- lear spectroscopy. But astronautics became the main interest and aim of his life. He was the corresponding member of the 1AA in Peris, and a member of several IAA, and IAF committees* spoke at more than 20 IAF Congresses and was en honorary member of several foreign aeronautical societies. Dealing with almost all astronautics and space physics on papular level, his scientific of qualitative character - 277 -

can be pieced in following four subjects: 1/ nuclear energetics in rocketry, 2/ impact of astronautics on science, our civilization and mankind; various non-selected problems in astro- nautics, 3/ evolution of matter in the Universe; planetology, 4/ life in the Universe. During his several last years dr Wolczek was dealing mainly with subjects /3/ and /4/. Scientific papers of dr WoZczek according to the above classification were revie- wed. Full list of dr Wolczek"s scientific papers was inc- luded. Independently uf his engagement in sciences I would like to pay my attention to the Vole of the humanistic elements in dr Wolczek'e creation and his personality. His knowledge in sciences, physics* chemistry and astro- nomy was very impressive. But his erudition in classical education, in literature, arts, musics was also sutstan- ding* He liked mountaineering. He admired the travelling as the means to become acquainted with the people and the- ir work. He knew actively several European languages /En- glish, Russian, German and French/ and made himself uner- stood in Italian and Spanish. He saw in the social and philosophical consequences of astronautics the synthesis of two important trends in the development of mankind: the natural, scientific and the humanistic ones. Hβ repre- sented himself the contradiction to the nsrrsw speciali- zation in science. He was thinking on the human affairs in the scale of the planet or even grater one. - 278 -

2M-03-295 PAGES FROM THE HISTORY OP THE HUNGARIAN ASTRONAUT1CAL SOCIETY by Istvan Gyorgy Nagy Hungarian Astronautical Society Budapest

Dealing with the history of the host-society of the 34th International Astronautical Congress - first of ail — the paper summarizes some data about Hungarian activities in the first half of our century in the field of jet propul- sion, rocketry and astronautics» In the middle of the fifties it became clear that the launch, of the first artificial satellites was approaching. An initiative originated from the astronomical section of the Society for the Dissemination, of Scientific Knowledge to set up a committee of astronautics as a basis of a later scientific society• In May 1956 the Hungarian Astronautical Committee, the predecessor of the present society was instituted. In those days the propagation of astronautical knowledge was the wain task of the commit- tee. Some committee-members composed the first Hungarian book about astronautics in 1957. In 1958 the first astronautical symposium in Hungary was organized by the committee. With the participation of several committee-members the permanent optical and radio observations of satellites commenced. The enlarged tasksdemanded the institution of a society to continue the work within, a broader range* its new form the Hungarian. Astronautical Society was set up in December 1959* Three years later the HAS has joined the IAP. Several members Qf the society work in the organs of the IAF, IAA and IISL. The residence of the HAS is in Budapest, local sections are active in four other cities in Hungary. The society has formed various working-committees for satellite geo- desy, remote sensing, apace biology and medicine, explo- ration of the Solar System, history of astronautics, apace law, apace technology. Some members of the HAS- composed a comprehensive Space Encyclopedia, in 1981. - 279- IAA-83--297

ОРГАНИЗАЦИЯ РЕАКТИВНОГО НАУЧНО-ИССЛЕДОЗАТЕЛЬСКОГО ИНСТИТУТА И ОСНОВНЫЕ НАПРАВЛЕНИЯ ЕГО ДЕЯТЕЛЬНОСТИ (К 50-ЛЕТИЮ СО ВРЕМЕНИ ЕГО ОСНОВАНИЯ) Б.В.Раушенбах Советское национальное объединение историков естествознания и техники АН СССР, Москва Описывается история организации первого в мировой истории научно-исследовательского института, посвященно- го технике ракетного полета. Рассматривается тематика работ института, охватывавшего все аспекты ракетной тех- ники, созданные конструкции и результаты их испытаний. Более подробно описываются работы приведшие к возникно- вению техники космического полета. Рассматриваемый пе- риод охватывает первое десятилетие работ института. Ш-83-2У9

О НЕКОТОРЫХ ЗАКОНОМЕРНОСТЯХ РАЗВИТИЯ РАКИТНЫХ ДВИГАТЕЛЕЙ НА ТВЕРДОМ ТОПЛИВЕ Г.Ю.Мазинг Советское национальное объединение историков естествознания и техники АН СССР, Москва История развития РДТТ рассматривается как троичный цикл отрицания. Двигатель на баллиститноы топливе с вкладным зарядом (начало XX в.) представляет отрицание двигателя на дымном порохе, являясь противоположностью его по типу топлива и основным элементом конструктивного решения. Современный РДТТ на смесевом топливе, являясь отрицанием отрицания, представляет собой возврат к изна- чальной схеме, но на более высоком техническом уровне и с сохранением позитивных моментов отрицаемой схемы. Основное внимание уделено отправному звену цикла - ракетному двигателю на дымном порохе, характеристики ко- торого просматриваются на примере ракет XIX в*. Автором была проведена реставрация тягово-баллистических характе- ристик русских пороховых ракет этого периода. На основе современных методов внутренней баллистики РДТТ установлен характер изменения давления в ракетах с поддоном, оценена величина начального и конечного давле- ния в двигателе, а также значение реактивной силы (тяги) и тяговооруженности. Удельный импульс для двигателя с поддоном был опре- делен по данным опытных срельб ракетами с утяжеленными боевыми частями, проведенными К.И.Константиновым в 1849 г. Были рассмотрены особенности внутренней баллистики и оценены тяговые характеристики бессоплового двигателя. На основе предлагаемой модели развития РДТТ просле- живается изменение во времени его основных параметров -• удельного импульса и коэффициента массового (весового) совершенства. - 281 -

IAA-B3-3<><) Leonhard Killer's Importance for Aerospace iJciericea - On the Oceanian of the Bicentenary of Buler'a Death Werner Hchulz, Braunschweig, FR(f Deutsche (Jesellschaft fiir Luft- uiid WHumfalirt. ('K;].H)

Leonhard Euler, who was born I'.i April 1707 in Hasel anil who died 1tt September 1783 in St. Petersburg, was the moat important mathematician of his time. In vi^v of the extra- ordinary diversity of his work, almost all branches of ma- thematics as well an mechanics anJ their related fields of applied research - celestial mechanics, fluid dynamic.'?, ballistics, naval sciences, engineering - owe basic fin- dings to him. His productivity was quite unbelievable. The edition of his Complete Works, wrioh was begun in 19'', has not been finalised till this day. The lecture deals with those findings in Euler'o books ami papers which have contributed to aerospace sciences. Kul^r'fs "Wechanica" in two volumes with its consequent application of analytical methods instead of the so far usual more cir- cumstantial geometrical-synthetic procedures has become of fundamental importance for dealing with problems of dynamic* such as also occur in flight sciences. In flight mechanics, guidance and control and structural mechanics we come across Euler's name in connection with the Ruleriari angles, the Eulerian gyroscopic equations and the Kulerian column buck- ling equation. In fluid mechanics hydrodynamics of nonvis- cous flows with Euler's equations of motion is still a start- ing point. Euler wrote treatises on turbines, and the turbine equation goes back to him. Hi3 translation into (Jerman to- gether with his annotations made the book of the ftnplishman Benjamin Robins "New Principles of Gunnery" a basic reader in ballistics. It was Pluler who considerably developed the methods of calculus of variations which are .«sed in ordpr to obtain optimal solutions to problems of flight techniques. And as far as space flight mechanics go, the res»O ts of Eu- ler's "Theory of Planetary and Gometary Motions", particu- larly his contributions to the calculation of disturbed or- bits, but also more specialised treatises, are still of in- terest today. His last paper, on which he worked shortly be- fore his death, dealt with the theory of the balloon, n sub- ject of special actuality at the tir;e because of the first ascent of a balloon by the brothers l"nntgolfier In the sum- mer of 1783. - 282 -

IAA-83-302 Communications Satellites: The Experimental Years Burton I. Edelson NASA, Washington, DC, USA

Six years, 1956 to 1964, were particularly fruitful ones for the development of comnunications satellites. The period started with the launch by the Soviet Union of Sputnik-1, 4 October 1957- This event startled most of the world by demonstrating a capability to place artificial satellites into low Earth orbit. Hovever, some telecoRinunications engineers had anticipated the space age. Arthur C. Clarke, then an RAF officer, described in 1945 how a "space station" in a geostationary orbit might be used for global television broadcasting. Then in the early 195Ofs, John R. Piere** of Bell Laboratories in the USA, designed several system configurations using communications satellites in both medium altitude and geostationary orbits. These systems promised to provide great benefits over terrestrial microwave relay and undersea cables.

With the dawn of the space age, immediate attention was given by both military and civil research organizations to developing the technology and testing the concepts to realize the concepts of Clarke and Pierce. Very rapidly, projects by the name of Score, Carrier, Echo, Telstar, Relay, and Syncom were pursued; satellites built and launched; ground stations constructed; and transmission systems developed—completely setting the stage for commercial operation of communications satellite systems—all in six years!

Those projects, 11 satellites in all, settled the important systems questions—active or passive satellite? What orbit? What frequency? What services? Components, devices, and - 283 -

subsystems were developed tr adapted from radar and missile systems, terrestrial microwave, and even astronomical systems. Host importantly, all the spacecraft technology—structures, stabilization, electrical power, propulsion, thermal control; and all the communications subsystems technology—solid state receivers, filters, travelling wabe tube amplifiers, lightweight antennas; all were developed, tested, and demonstrated to make the geostationary orbit communications satellite feasible. The stage was set for operational systems.

When Intelsat was formed in August 1964 and launched its first geostationary satellite, "Early Bird" eight months later, commercial service was inaugerated. Great expansion and evolution of systems and services have taken place in the two decades that followed Early Bird, but nothing like the development In the six "experimental years" that proceeded it.

\i - 284-

IAA-83-303 SOME VIGNETTES FROM AN EARLY ROCKETEER'S DIARY

Bernard Smith King George Virginia, U.S.A.

Scanning a half century of rocketry, one can often discern disparities, previously unrecognized, between early dreams and the realities of history. Fascination with remarkable events in the 1930s led to the design ami construction of the first liquid-fuel rocket publicly launched in America; the first hybrid-fuel rocket motor ever tested; the first anti-submarine torpedo transported to the target by rocket; the first anti-radar rocket, launched from aircraft; and, shortly after Sputnik the first attempt to launch a satellite by means of a reuse- able first stage, all of which involved the author. Thesp; thoughts are inescapably mingled, with misconceptions that motivated the author's original entry into rocket and aerospace activities, notions that still persist in some modern minds. Over the years, the opportunities in the field that bequeathed rare thrills to individual pioneers now seem overwhelmed by vast corporate efforts and evermore denied to young rocket neophytes.

The author begins his history with an announcement in late 1932 that the American Interplanetary (later. Rocket) Society would'hold a meeting at New York's American Museum of Natural History and ends it by recounting the plan a quarter of a centufy later to place into Earth ovbit a small airplane-boosted satellite.

The author's involvement with building and firing ARS rockets Nos. 2 and 3 is recounted, giving rise to his description of an amateur rocket's construction as something th.lt "was accumulated." On 14 May 193 3, the au 1.1KM became, one day before his birthday, the first lad in America to launch publically a liquid rocket (ARS No. 2, from Great Kills, Staten Island). ARS 3, tested in September k934 at the same location, was a failure; it later went on display at the 1939 New York World's Fair,

_ a ^_ . - 285 -

Events Leading to the author's move to California are given, leading in 1939 to the formation under his presidency of a new rocket group, the California Rocket Society. Rocket testing by the society was done in Arroyo Seco, a riverbed near Pasadena. Perhaps the most unique contribution to rocketry made by the new group was the hybrid motor (solid carbon—fluid oxygen), which exhibited desirable characteristics of safety, controll- ability, and simplicity. With America's entry into World War II, amateur experiments were soon terminated.

After four years of preparation for the transition from amateur to professional, the author joined the United States Navy in 1948 as a civilian scientist and devoted the next decade to the development of rocket-propelled weapons.

The paper concludes by summarizing immediate post Sputnik 1 plans developed by the Navy to launch a small satellite. The first stage was to be a Navy fighter bomber, which would release a 3,000-pound five stage rocket at 40,000 feet altitude in the proper direction and at the right inclination and velocity. The ignition of each successive stage would be accomplished by timers and horizon scanners, and the flight path in each case would be ballistic. A small orbiting radio beeper would be released from the final stage. Three launch attempts were made. - 286 -

IAP-83-306

THE MESSAGE AND THE EXPERIENCE OF THE SITE PROJECT

E. V. Chitnis & K.S. Karnik Space Applications Centre Ahmedabad 380053, India

Abstract

The Satellite Instructional Television Experiment (SITE) a unique effort aimed at studying the possibilities of satellite broadcasting for education and national development. This year joint India-USA project was carried out in 1975-76 using the ATS-6 spacecraft. This paper briefly describes the experiment and its major findings. It goes on to distil the learning experien- ces derived from SITE and analyses the extent to whi< h these have influenced the design and configuration of India'H domeslit satellite system, INSAT. INSAT 1 By which will serve as a replacement for the short-lived INSAT-IA will be launched shortly and will (.»• operational by the end of this year. Its payload includes two S-batid TV transponders capable of broadcasting directly to augmented TV sets. The paper examines which lessons of SITE are being applied in the planning and operationalisation of the TV system and discusses why others are not being taken account of. Major issues confronting TV system planners in developing countries like India are highlighted and the possible role of satellite broadcasting discussed in this context. The paper concludes by outlining an "ideal scenario" for a large, multi-lingual country like India, towards which TV planners could attempt to strive. - 28? -

XXXIVth IAF Congress TAF-83-307

EDUCATION AND COMMUNICATION SATELLITES: OPPORTUNITIES FOR OUTREACH

Dr. Robert T. Filep, President Communications 21 Corporation Dr. Joseph N. Pelton, Executive Assistant to the Director General, INTELSAT

ABSTRACT The opportunities and problems posed for all areas of education by the present and planned increase in communication satellite capacity is explored. An analy- tical matrix of the characteristics of narrow band ser- vices through wide band services in relation to cover- age and interconnectivity for educational use is pro- vided. A review of available and planned satellite systems is given with attention to those with capacity to serve rural areas. Elements educators should con- sider in defining the major problem areas of a potential system involving satellites such as software, hardware costs are outlined. Successful applications of commun- ication satellites, a concept for a school or home integrated Forum Facility, and potential initiatives in the area of satellite based open learning systems are discussed.

•-••• - 288 -

IAF-8>308 Satellite Broadcasting — The Best Way to Meet the Needs of Television Education in China

He Jinying

Institute of Broadcasting Science, Ministry of Radio & Television, PRC.

ABSTRACT

The key to the "four modernizations" in China lies in the modernization of science and technology. It is impera- tive to train professional personnel in various fields with great efforts, and raise the whole country's level of science and technology. In this respect, radio and televi- sion university is one of the most efficient approaches. China opened her Radio and Television University four years ago with nearly 800 thousand students. In 1982, there were*200 thousand students who had completed various courses — a rate of 2/3 of the annual graduates of the regular universities in China. Besides, much more viewers are taking varied lectures and training courses run by the CCTV. The sales volume of teaching material of one of the courses amounts to 2 million. These CCTV programs are quite popular and influential in China.

At present, however, the main limit for further ex- pansion of TV education is the low coverage rate of tele- vision broadcasting itself. To tackle the problem in a country like China with a vast expanse of territory and a varied topography, satellite broadcasting should be the most economic and effective means. -289 -

For the time being, in view of our country's economic possibilities, it may be reasonable to start with a re- ceive-rebroadcast type satellite broadcast system, i.e., to launch a medium-power K-band broadcast satellite. The TVRO ground stations, using cheap receiving equipments with 2-3 m diameter antennae, receive the satellite signal end rebroadcast it by medium or low power transmitter to cover the adjacent regions. With the rebroadcasting trans- mitters located right in the populated areae, the radiated power could be fully utilized while interferences between transmitters would be minimized. In some cases, community receiving would be feasible. Such a system can reduce the cost of receive-rebroadcast stations and viewers would be able to receive high-quality TV programs including educa- tional programs without any additional costs. In such places as Tibet and Xinjiang where transmission of TV pro- gram via terrestrial TV network is almost impossible due to the vast and varied topography, satellite broadcasting would be actually an exclusive means. - 290 -

JAP-R.1-310 Hj./i;lier rnd ioengineerjng education and apace

Efimov I.E.

Schakhguildynr. V.Vn ( USSR ) Intercostnos Council USSR Academy of Sciences Radioengineering education is closely connected riUi tho general tendency of the development and perfect ton of the space communication systems. Al] the achievements of radionlectronios, communication engineering, microelectro- nics and computerlng engineering are concentrated in sp-^co. It io here that the latest achievements in the communication theory and the technology control and microproces3 engineer- ing can be realized. Tho development of space communication systems influences on the cuerrxcula and programme of pre- paration of radioengineers in a great extent. It is neceena- ry to mark tho main trends in perfecting the curricula and programme. Tho conquering of the new ranges required the creation of the new meclianizms for generation and amplifica- tion of fluctuations of these rang.. ••- and the necessity of mastering their theories in the course of study. The deve- lopment of principals of accelerated automated designing of radiotransmitting and radioreceiving devices, optimisation them by a number of parameters (reliability, accuracy, sta- bility of work) required the essential correction of the traditionally-existed programme or theae courses, Introduc- tion the section1: of mathematical modulation in them, study- Ing thoroughly the use of computers for investigation of racHoengineering devices. The creation of separate units of modern receive-transmlt complexes on the basis of the use of the technology required the vast expansion of time that was given in curricula for studying schemeengineering and microelectronics. For the last period of time great pro- gress was made in the application of digital methods of the data, transmission in the communication systems, in the de- velopment of high-effective modulators and demodulators of discrete signals. In thia connection there appeared the nece- ssity of introduction of subjects in the curricula which are connected with the deepened study of digital technique and the use of microprocessors. It was the application of micro- processors that allowed to process signals just on board of the satellite, to increase the functional opportunities and reliability of radio engineering units. The development of high-directional controlled multibeam antennas allowed to increase greatly the efficiency of the satellite systems. In this connection great attention is given to the study of the theory and technique of the controlled antenna network in the curricula. Taking into consideration all above mentioned it is to be emphasized that at present the demands to the preparation of future specialists who are able to solve complex problems - 291 - of the designing and exploitation of up-to-date communi- cation Bystem3 increased greatly. The affect of space on the development of new ideas in engineering is great. The transmission of TV and radio- broadcasting information, weather forecast, exploration of natural earth resources, study of the Universe - this is an incomplete list of branches of science and engineering connected with the use of space apparatus. The aim of high- er radioengineering education is to prepare the future en- gineer to the possibility of solving sofistioated problems of scientific-technical problems. - 292 -

IAF-83-312

Prospects of Satellite Education in Indonesia R. Sunaryo Indonesian National Institute of Aeronautics and Space

Indonesia, with a recent colonial past, endowed with a vast territory and in excess of 150 million people living on 6C00 out of the 13,600 islands, is working hard to solve a multitude of specific and serious problems in providing much-needed education to its people. As a result of the course of history, educational facilities have been concentrated on the island of Java, being for centuries the site of capitals of Kingdoms and subsequent colonial governments, and inhabited by 65% of the nation's population. The Indonesian Government's policy in quest of more opportunities for all the people to enjoy better education more equitably, has met many challenges on various fronts, the more serious ones being the shortage of qualified lecturers and the great distances between educational centers especially in the eastern parts of the country. In the past -and until now- these difficulties have resulted in a mere trickle of well-to-do students coming to Java and the rest crowding in inadequately staffed "eastern" universities where long-awaited professors from Java made sporadic teaching visits. The results are poignantly predictable: overdue programs, sub-standard academic performance and frustration. The advent of satellite communication has provided new hope for solving the problems. Studies have been made and a number of papers have been written on the feasibility of utilizing the new technology for making qualified teaching available to nine scattered universities on the islands of Kalimantan, Sulawesi, Maluku and IHan Jaya. Outside experienced help from the United States (USAID) was recruited and also the United Nations (UNESCO) stepped in. While the Palapa A Satellites with 12 transponders each provide the realistic hardware base for the studies and plans of linking the nine - 293 - eastern universities with the source of teaching material and staff In Java, I.e. the Bogor Institute of Agriculture (IPB), the newly launched Palapa B-l and forthcoming Palapa B-2 both with enhanced capabilities and doubled power, are designed for the actual Implementation of the distant teaching project and other applications of the space technology for the dissemination of a wide range of knowledge to urban and remote communities. A detailed study of the Implementation plan 1s underway. - 29* -

1AF-8J-JI5 ORBIT PREDICTION FOK IRAS US1NO VECTOR AN!) ANALYTIC TECHNIQUES DΓ R Holdnvay Science mid Fngineering Research Council, Kuthti ford Applrton Laboratory, Space and Astrophysics Division, Chi 2ton, Didcot, Oxfordshire, UK.

The Infra-Red Astronomical Satellite (IRAS) is a joint ventuie the United States of America, the Netherlands and the United Its purpose is to provide the first all-sky survey at infra-r»d wave lengths, using a Ritchey-Chretiett helium-cooled tHusiopr. I hi satellite was successfully launched into a g00 Km rirnilar twilight orbit on 2b January 1983. In its first five months of operation it has already detected several thousand newly identified infra-tc) sources and two new comets.

The Operations Control Centre for IRAS is at the SKRC's Rut hei font Appleton Laboratory in Oxfordshire. All tracking and orbit dcif-rmiit- ation for IRAS is done from the OCC, using a 12 metre s-assegrain main antenna. There was a need on the IRAS project (common to many other space projects) for a compact general purpose computer program to provide accurate orbit and ephemeris predictions. This paper des< rilx-s the mathematical approach to the prograr, SPIRAL, whirl) has as its m.iin function the* prediction of orbital elements and events for war farth satellites. The approach adopted is to use the vector constant 8 of inverse square law motion resolved along suitable axes. This method of defining the equations of motion providt-s a good stable inundation for urbit development and prediction. The accuracy of orbital element prediction is then sufficiently high for a purely analytic approach to be adopted for the algorithms in the remainder of the computer piogtam. This applies particularly for the ground station view timo calcula- tions where it has been found that a four pass iteration can μ^e vt-ty accurate view times. Other options available in the program include Earth and Moon eclipse, radiation zone crossing times, solar cell d»-r»v calculations, and an ephemeris of latitude, longitude and altitude. A second important technique that can be applied is one related in t\» prediction of the decay of the orbital element semi-major axis. As well as depending on satellite geometry, one of the most important influences is that of solar flux at the wavelength of IO.7rm nut tenth of a second over one day. As an example of a typical series of - 295- delta values, found on MJD 45373, we have:- Aa * .03km Ae - .00007 Ai - .001° Aβ - .006° A(W+M) - .004°

In addition, the error in predicting satellite position is better than l| seconds over one week, and better than 15 seconds over three months. -296 -

IAI" 8}--! 17

Appliration of the Stroboscopir? Method t.o Equinocti al Elements

E.A. Roth ESOC Darmstadt The stroboscopic method had been developed - based on Lagrangefu equation written for Keplerian elements - for various perturbations affecting the orbit of terrestrial or planetary orbiters. Tn a reeeii* paper (Roth, 1979) the mathematical background of the approach has bee.i investigated and it has been shown that also higher order then- r'.es can be constructed. The method is, moreover, not restricted to Keplerian elements, so that it is possible to avoid the singularities for small eccentricities and/or inclinations. A particularly suited set of elements are the equinoctial elements (Cefola, 1972) :

x, = a (or p)

x2 = f « e cos (d> + ft) , x3 = g = e sin (a> + $2)

x,, = h = tg^cosfl , x5 = k = tg^sinO y = u> + fi + v where v is a fast angular variable.

The Lagrange equations can be writtewritt< n as dx = eX(x, y, t) dt dy <> jg = u(x, y)+ eY(x, y, t) T where x - (a, f, g, h, k) . The functions X.» Y are in the conservat- ive case sums of the Poisson brackets multiplied by the corresponding partial derivative of the potential V. The stroboscopie method requires the use of the fast angular variable y as the independent variable. The first order Lagrange equations take the form :

with F * X/u and G • Y/u. The last term in the second equation - 297 - represents the- second integration required for the time.

Perturbation by the central body.

In this case it is convenient to use the true longitude L = w + Q + f as fast variable and to replace a by the semi-lntus rectum p - a(1-e ). The perturbing potential has the form

C cos m (u -- 0) + S sin ; nm nm and can be written in equinoctial elements (C'efola, 1976). Integrat- ing (3) over one revolution from L = 0 to L = 2T\ gives the increments Ax' ', At '. For slowly rotating central bodies the siderial time H can be kept constant during one revolution.

Perturbation by a third body.

The perturbing potential can be expanded in the form

(5) where p' and r1 are the mass-parameter anu the distance of the third body and i/> is the angle between the satellite and the third body. Tn this case it is more convenient to introduce the eccentric longitude F=u) + fi+Eas independent variable since this simplifies conside- rably the integration (Roth, 1982). Contrary to the case of the Keplerian elements, the integration runs now from Fo to Fo + 2IT, where Fo corresponds to L = 0. Only for small eccentricities the initial value Fo = 0 leads to second order errors; then the final re- sult becomes much simpler.

References Cefola, P.J. (1972) Equinoctial orbit elements - Application to artificial satellite orbits. ATM Paper 72-937.

Cefola, P.J. (1976) A recursive formulation for the tesseral disturbing function in equinoctial variables. AIAA Paper 76-839.

McClain, W.D. (1977) A recursively formulated first order semi-ana- lytic artificial satellite theory based on the genera- lized method of averaging. Vol. 1, CSC/TR-77/6O/O.

Roth, E.A. (1979) On the Higher-Order Stroboscopic Method. •ZAMP, .30(2), 315-3?5. Roth_, E.A. (1982) Construction of a consistent semi-analytic the- ory of a planetary or moon orbiter perturbed by a third body. Cel. Mech. 28(2), 155-169. -296 -

1 A»- IIH

Naluial Rpcntry Predict Ions of a »;!.)•;»• F-iilh '\H <• II i I I 11 ii M t rat ion by co.sMOj: [4()A.

!•'. NOIIKl. }J. PAIIiliKT P. RNCUIMKH O.

C'FNTRF NATIONAL D' V.TUOFS, KPATIAI.BK Tiilll.OHKK

Methods and models lo makfi piodii-t inns (if sa • »'I I I t e Ira jiHitories are very oftf-n uyed in a well defined i;onl«!xl-. WliPn trying to i>redict natui.il inpiiti y, ii t the opportunity of validating or establishing HH- .limits of tliesp methods and models, hPf,iiis» the i:in rtiundJncfR of the trajectory varies rapidly w < i r> i (me.

Several points havp been appruai.'linii when it wts a matter of making predictimiB for the two parts of HIP

COSMOS 14O2 satellite, in particular the modt> J i pa t i oi. of the air drag force at several level of aliltu-.les

Here, are considered the adjustment of the. effective cross sectionnal area over mass ratio, the nnnie) isa tion of the drag coefficient with respect to altitude the influence of predicted solar activity end yeoma gnetic activity (during COSMOS, solar f lilies and magnetic* storms appeared). A model of t r a ject ni y fr»m '1O km to ground is also described.

Moreover some a posteriori tests were undertaken in older to validate parts of the assumptions. - 299-

Paper N°. IAF-83-3l«l

Three-Body problem - A test f escape valid even for very small mutual distances

* ** *** C. Marchal - J. Yoshida - Sun-Yi-Sui

* ONERA - 92320 Chatillon - FRANCE

** Kyoto Sangyo University, Motoyama, Kamigamo, Kyoto 603, JAPAN *** Dept of Astronomy, Nanjing University, Nanjing - CHINA

The usual tests of escape are efficient when at least two of the three mutual distances are large, but they are gene- rally useless when the mutual distances are small and they give an inaccurate picture of the region of phase space where occur bounded motions.

As the other tests ours uses the Jacobi decomposition of the 3-body motion, with r being the mutual distance of the two nearest bodies and R the distance between their center of mass and the third body. We also define cases of insulation : the third body is "isolated" when the Sundman function is larger than the three critical values corresponding to the three families of Euler motions with collinear central configurations (an upper bound of the ratio r/R can indeed be given in terms of the Sund- man function). We thus arrive to the following : the third body escapes, and the motion is unbounded, if at any time that body is isolated and has an hyperbolic velocity. - 300 -

Large values of the Sundman function occurs not only for large mutual distances but also for small and especially very small mutual distances (that function goes to plus infinity with H and/orR~and/or|de/5lt| ). We are thus able to draw accurate pictures of the zone of bounded motions especially in the vici- nity of triple close approaches as can be judged with the follo- wing results and conjecture.

Let us consider three given point-mass 1RA , Uij,IR3 and all their possible bounded 3-body motions wich a given angular momentum C. We will use the axes of the center of mass and we will analyse the variations of the moment of inertia IsrHi^ r™+

Among the possible bounded motions we found the three usual families of elliptic Euler motions and a beautiful result would have been the following : "the greatest lower bound Io of the moment of inertia I for the three families of elliptic Euler motions is also the greatest lower bounf of I for all bounded 3-body motions of the same masses and angular momentum".

Since elliptic Euler motions are bounded it is obvious that the latter greatest lower bound cannot be larger than I^ and with our test we found that it is always larger than WW L for any choice of •β^fll TL,C. We of course conjecture that there is always equality between these two greatest lower bounds, i.e. that the above statement is true. It is already true for some ranges of value of ratios of the three masses.

Av# Scale considerations show that Ie is proportional to C/Cr , with G* being the constant of the law of universal attraction.

The ratio TLXx/C is a classical and complex function of the three masses ; iftn.is the smallest of the three masses that function is :

We thus obtain accurate limits for the Sundman statement : "three- body motions with a non-zero angular momentum cannot approach triple collisions".

Our test leads to many other results and especially to the smallest delimitation of the region of phase space where occur bounded motions. That zone is much smaller than generally expected and numerical computations of periodic orbits show that we approach very near to the true limit. - 301 -

IAP-83-32I g . ON THE ENSURED ACCURACY FOR DETERMINING EPHEMERIS OF COMET HA1LEY BASED ON ON-BOARD OBSERVATIONS OF IT A.A. Sukhanov, F.E. El'yaaberg Space Research Institute, USSR Academy of Sciences The expected ensured errors in determining ephemeris of Comet Halley are estimated based on observations of the comet from the Earth and from the VEGA spacecraft. The looked for errors are analysed for different con~ tents of the measurement data. Simultaneously the opti- mal strategies are selected in order to use together the astronomical and on-board observations of the comet, - 302 -

IAP-83-322 DESIGN OF SPACEFLIGHT TO SMALL BODIES OF THE SOLAR SYS- TEM WITH THE AID OF A DISPLAY INTERACTIVE SYSTEM R.K. Kazakova, A.K. Platonov A series of problems are discussed for solution of which a display interactive orbit design system was used. The evolution of cometary orbits is considered for a long period of time. On an example of flight to Halley the transfer trajectories with the Venus flyby are given along with the spacecraft orientation during the flyby and the conditions of the Halley observations from the ground-based stations* - 303 -

IAF-83-325

All Elegant Lambert Algorithm Richard H. Batttn and Robin M. Vaughan

Of the many techniques extant for solving the two-body, two- point, time-constrained orbital boundary-value problem, common- ly known today as Lambert's problem, none is more conceptually elegant than the classical method devised by Gauss. The simplicity of Gauss' method would certainly have been attractive to the mo- dern astrodynamicist except for two major flaws — the method is singular for a transfer angle of 180 degrees and the conver- gence rate is extremely slow when that angle is not very small. In this paper a new algorithm is described which exactly parallels both the mechanics and the elegant simplicity of the classical one but is completely devoid of the two basic faults of the original. The equations of the new method are universal and not singular for the 180 degree transfer. (They are singular for a complete revolution through 360 degrees but this Should not be catise for great alarm.) Furthermore, convergence is both remarkably rapid and almost Uniform as welt as being essentially independent of the initial gttesft. It should further be emphasized that all of the advantages of Gailse' method are inherent in the new method — notably, the preservation of numerical accuracy for small transfer angles (of the order of 2 or 3 degrees, for example). iAP-83-326 GENERATION OP TRAJECTORIES BY MULTIPLE PLANETARY SWINGBYS

Hlroki Yokota and Toru Tanabe Department of Aeronautics, Faculty of Engineering University of Tokyo, Tokyo, Japan

ABSTRACT

Thie paper discusses a poesible application of a multiple planetary ewingby technique, which makes use of at most three gravity-assist planets: Earth, Venus, and Jupiter. Various combinations of encoun- tered planets are considered (e.g., a multiple Venuci ewingby, a multiple Earth-Venus swingby, a multiple Earth-Venus-Juplter ewingby, etc.), and each of the energy exchange mechanisms between a spacecraft and planet(s) is investigated as well as the angular momentum exchange mechanisms. Focusing on attainable orbital elements, the capability of each ewingby technique Iβ clarified.

In order to determine a planetary encounter sequence, which realizes a given mission in a minimum flight time with the prescribed launch velocity increment, a sub-optimal control strategy is proposed. This strategy is built up with several awingby subsequences, in which a forward dynamic programming approach is partially applied. It is shown that once the spacecraft reaches Venus, It could theo- retically take on almost any conic section, such as a hyperbola, a parabola, a rectilinear ellipse, or even a retrograde ellipse through the multiple planetary ewingby process.

Four interesting interplanetary mission designs (Ml tc M>1), which may not be possible by a conventional direct launch technique, are investigated: Ml: Solar system escape mission; M2: Sun encounter mission; M3: Out-of-the-ecliptic mission; N4: Retrograde mission; through the use of the multiple Earth-Venue swlngby and the multiple Earth-Venua-Jupiter ewingby with as little as a 3.0 km/sec hyperbolic excess velocity at launch from Earth. In order to grasp the problem structure and to gain a quick survey of possible solutions, computations are first carried out assuming the circular and coplanar planetary orbite with arbitrary initial planetary locations based on a patched conies method. Then, for - 305 - actual planetary locations with a given launch date from Earth, trajectories In a three dimensional model are reconstructed Including the planetary Inclination and eccentricity. Results are compared with the conventional direct launch technique and with a single Jupiter swingby technique in terms of the Earth launch velocity increment, the flight time, and the available launch opportunity.

When the initial planetary locations are arbitrarily chosen in a two dimensional planetary model, it is shown that missions with the multiple Earth-Venus swingby take considerably longer flight time (10.8 years, and 33.3 years for missions Ml and M2 respectively, while 1.1 years, and 0.2 years by the conventional direct launch technique), although the launch velocity Increment Iβ quite small (only 3.0 km/sec Is required both for missions HI and M2, whereas 12.3 km/sec, and 29.8 km/sec are necessary for missions Ml and M? by the conventional direct launch technique). Missions using the multiple Earth-Venus-Jupiter swlngby with the same 3.0 km/sec launch velocity increment greatly shorten the flight time compared with the multiple Earth-Venus swingby (5.2 years for mission Ml, and 9.0 years for mission M2). Likewise, with the use of the multiple Earth-Venus-Jupiter awingby, mission M3 with 1.76 AU semilatus rectum and mission M4 with 0.69 AU perihelion distance are achieved with 10.1 years and 26.8 years flight times, respectively. The latter two missions by the conventional direct launch technique require 42.1 km/sec, and 57.6 km/sec launch velocity increments (actually infeasible at present) with 0.3 years and 0.4 years flight times. Meanwhile, through the use of a single Jupiter swingby, taking about 3 to 4 years flight times, all four missions are achieved with 9 to 14 km/sec.

Taking into account actual launch opportunities in the years of 1989 to 2001, missions Ml to M4 are reconstructed in a three dimen- sional planetary model. Even in the same mission, the favorable flight sequence differs depending on the launch date from Earth, and an additional few years flight time (e.g., 2.1 to 4.7 years for mission Ml) is required to reach Jupiter compared with the results of the arbitrary initial planetary locations. For instance, when the spacecraft is launched from Earth in June 1999, it takes 7.3 years to realize a hyperbolic orbit with respect to the sun (mission Ml) through the use of the multiple Earth-Venue-Jupiter swingby, and when the launch date is chosen to be August 1994, the spacecraft achieves a rectilinear ellipee towards the sun (mission M2) after a 9.4 years flight time. It Iβ observed that due to the planetary Inclination and eccentricity, the trajectories designed in a two dimensional planetary model with a 3.0 ka/sec launch velocity increment should be added to by an extra 640 m/sec velocity correction in average.

In conclusion, the proposed multiple planetary ewingby process, especially the multiple Earth-Venue-Jupiter awingby process, can be applicable to generate Ml to M4 trajectories with 3 to 4 km/sec launch velocity increment and with a flight time of the order of 10 years. IHK-8? 357

RELATIUISTIC ASTR0DVNAM1CS: THE PROBLEM OF PAVLOAU OPTIMIZATION IN A TWO-STAR EXPLORATION FLIGHT WITH AN INTERMEDIATE POWERED SWING-BV. Giovanni Uulpetti Telespazio SPA per le Comunicazioni Spaziali Uia A. Bergamini 50 00159 Rome Italy

There is an increasing interest by many investigators in USA and Europe towards the highly attractive performances that space propulsion systems based on the antimatter- matter annihilation process would exhibit. Although sys *:e._ matic studies about this utmost challenging field began only few years ago* however both interplanetary missions and nearby-star exploration flights are under a progressive investigation together with concepts of engine design. Relativistic Astrodynamics problems would pr&ssnt o. number of hew aspects if a spacecraft were endowed with such a very high energy density

IAF-83-328 AN ANALYSIS OP CHARACTERISTICS OP THE SATELLITE AUTONOMOUS OPTICAL NAVIGATION SYSTEM V.V.Ivashkin USSR Academy of Sciences Moscow

The autonomous navigation system characteristics are investigated for an artificial satellite around a pla- net. Navigation is based on the optical tracking of stars near the planet's horizon • The recognition of stars and the measurement of angles of star elevation above the horizon are carried out. The subsequent statistical processing of the measurements allows to determine the satellite orbit elements with an accu- racy dependent on the measurement accuracy and prog- ram. The analysis employe an exact numerical algorithm and approximate numerical - analytical technique* The na- vigational accuracies are studied in relation to in- dependent and correlated measurement errors. Compari- son is made for navigational accuracies determined by the above two methods. It shows that the approximate technique allows rather well (with an error less than ^0%) to find navigational errors even at a small num- ber (3-6) of times for measurements per a revolution. When this number is increased the methodical error of the approximate technique quickly diminishes. The na- vigational accuracies are obtained for the satellite in an orbit with altitude of 300 to 36000 km.

The navigational algorithm was tested in direct nume- rical simulation and its convergence bounds were de- termined. The latter show admissible deviations of initial values in orbital elements from exact ones* The analysis shows that the algorithm is stable at rather large errors in giving the values of initial approximation. - 508 -

J.AF-83-329 Terminal Bavigation for

Benefits of International Cooperation

Rolf E. Munch

European Space Operations Centre European Space Agency Darastadt, Vest Gernany

ESA's GIOTTO spacecraft is planned to fly-by Halley's Comet in 1986 with a distance considerably leas than 1000 km. To achieve this goal, a variety of measures are being considered, including international cooperation between ESA and Spacn Institutions of the USA, Hungary and the USSR. GIOTTO's terminal navigation is an example which clearlydemonstrates the benefits of such a cooperation.

The GIOTTO spacecraft will be launched in July 1985 by an ARIANE launch vehicle and injected into a geostationary trans- fer orbit. With the help of a solid propellent motor a trans- fer to a sun-centred orbit will be realised by firing it at an appropriate perigee passage. The spacecraft will then travel essentially in tha ecliptic plane until the encounter with the comet. The encounter is planned for a fixed arrival time on March 14, 1986, based on ground station availabilLty and with a nominal target point at several hundred kilometers away from the comet nucleus.

Several measures for the successful performance of the space- craft navigation to the comet have been taken and are being investigated. The most important ones are connected with international cooperation. Firstly, the astrometric observat- ions of the comet necessary for its orbit determination will be provided by ground-based observatories coordinated by the International Halley Watch. Secondly, the ESA investments into deep apace support in terms of stations and software fac- ilities are being supported by a consultancy arrangement with NASA/JPL, including provision of DSH tracking data for valida- tion and back-up purposes. Thirdly, an international cooper- ation attempt is being made combining all comet missions being planned, i.e. the Japanese, the Soviet-European, the NASA (comet Giacobini-Zinner) and the ESA missions. Cooperation is planned in all areas, the navigation part being concerned with improvement possibilities for GIOTTO based on earlier fly-by's of the two Soviet-European VEGA spacecraft. - 309 -

The paper deals with the terminal navigation process for GIOTTO, covering approximately 10 days of operations before the encounter which will be controlled by ESA's European Space Operations Centre, ESOC, Darmatatlt, W.-Germany.

The scientific requirements for the fly-by define a distance that it is by far smaller than what any of the other space- craft is targetted for. Stringent requirements on accuracy for the navigation process have therefore to be satisfied. The most important areas are the orbit determination of the spacecraft, the determination of the comet's ephemeris, and the optimal manoeuvering of the spacecraft. Host critical 1H the determination of the comet's ephemeris specifically in the time period before encounter. There especially, the comet's orbit will be disturbed by non-gravitational forces (outgaas- ing) around perihelion, and moreover, the comet will not be visible from earth (solar conjunction). Various measures have been considered for improvement of the accuracy for the cornet's orbit, including special observation techniques from earth-based observatories, observations made by spacecraft systems, and information about the earlier fly-by of the two Soviet VEGA spacecraft. For the optimum utilisation of the various information sources, technical, organisational and timing aspects have been analysed. This is resulting in a plan for the detailed activities to be performed during the last few days before encounter. The terminal navigation pro- cess thus established will lead to a considerable improvement of the GIOTTO targetting for the benefit of the anticipated scientific results. IAF 83-330 OPTIMAL AEROASSISTED RETURN FROM HIGH EARTH ORBIT WITH PLANE CHANGE Nguyen X. Vinh and John M. Hanson Department of Aerospace Engineering The University of Michigan Ann Arbor, Michigan 48109, U.S.A.

It is well known that the use of aerodynamic forces to assist in the orbital transfer can significantly reduce the fuel consumption as com. pared to the pure propulsive mode. But, in the published literature, not much effort has been done to analyze the coupling effect between space maneuver and atmospheric maneuver and its subsequent in- fluence on the fuel consumption. As an illustration of the fact that orbital flight and high-altitude atmospheric flight at hypersonic speeds can be considered as an integral problem in astrodynamics under a global optimization to find the combined aeroassisted optimal trajec- tory, we consider the problem of minimum-fuel return from a High Earth Orbit (HEO) with radius Tj , to a Low Earth Orbit (LEO) with radius r. , with occasional maneuvers inside the Earth's atmosphere Lt with radius R, while performing a prescribed plane change i .

The use of Chapman's variables allows the formulation of a set of dimensionless equations for atmospheric flight with smooth transition to space flight in the vacuum. For a given maximum lift-to-drag ratio, E*, which is the only physical parameter of the aerodynamic vehicle involved in the present formulation, the problem of optimal aerodynamic plane rotation is completely solved. Then, upon com- bining with the propulsive maneuver in the vacuum, the different optimal aeroassieted transfer modes are obtained. The different regions of optimality depend on three parameters: the ratios of the radii n = t./ i*_ , a= r,/ R and the plane change i . In the (n,o,i) space, sections of i = constant are displayed graphically for typical values of the plane change angle. They allow a quick assessment of the relevant optimal mode. Aβ a special case, it is shown that a return from a Geosynchronous Orbit (GEO) to a LEO is by the way of the aeroaseisted-parabolic mode, with plane change performed in the vacuum, and the process only requires drag capability of the vehicle. - 311 -

I.A.P. - 83-33^ STABILITY ANALYSIS OF THE MQffIQM ALONG RB-EHTRY

Vlhai Popeeou National Institute for Scientific and Technical Creation Bd. P&cii fir.820, 79622 Bucharest - AU

; t r a c t In this paper a olass of ieape.ri

The rotation motion equations for the Salyut-Soyuz orbital complex involving gravity gradient, and restoring aerodynamic torques allow natural introduction of a small parameter - a ra- tio of the longitudinal moment of inertia to one of transverse moments of inertia. Formal two-parametric integral manifolds are constructed by the Krylov-Bogolyubov1a method to describe oscil- lations and rotations of the orbital complex about the longitu- dinal axis directed approximately along a local normal. The mo- tions which belong to such manifolds are assumed to be nominal undisturbed motions of the orbital complex under the gravity gra- dient stabilization* Numerical study is carried out for the in- tegral manifolds constructed* It is shown that they can be uns- table due to a nonpotential component of the aerodynamic torque* The onboard measurements of motion parameters of the gravity-gra- dient stabilised orbital complex havt been processed and the ea- timates obtained for the aerodynamic parameters along with oooura- oies for the motion equations* - 315 -

IAF-83-336 DYNAMICS OP THE ORBITAL CABLE SYSTEM

V.V.Beletskii, E.M.Levin

Keldysh Institute of Applied Mathematicsf the USSR Academy of Sciences Institute of Machine Studies, the USSR Academy of Sciences

The orbital cable system ( OCS ) consists of a vehicle with an engine, a connecting long cable ( thread ) and a satellite-probe. Vehicle orbits the Earth in the vi- cinity of 200 km height and satellite-probe orbits in the vicinity of 100 km height. The air drag is compen- sated by the vehicle engine thrust. For the investiga- tion of the OCS motion the cable weightness, elastity and air drag are taken into account* Stationary moti- ons of the OCS are found and their mechanical charac- teristics are determined* Stability of the OCS statio- nary motions is investigated and restrictions on the OCS parameters imposed by the stability condition are determined* The OCS periodical motions that are close to the stationary motions are constructed* Simple ways of the OCS deployment in orbit are described. IAF-83-33R

SOTTO CADUTA

by

John A. Breakwe11 Lockced Missiles and Space Company Palo Alto, California (U.S.A.)

Filippo Grazinni Sc.uola di. Ingegneria Aerospatiale Ihiiversita t\c[>li Studi di Roma (ITALIA)

In the next few decades, the size of spacecraft can be expected to in crease tremendously. Accompany inp, this increase in sif.o will be an increa se in the. structural flexibility of these spacecraft. In ordei to attain full potential in both maneuvering and attitude control, new kinds of con tral laws which can accomodate this flexibility must be devised. Control theoreticians have anticipated the need for the new flexible si cecraft control theory, and many ideas have been developed. Most of the new theories depend in some way on infinite series expansions in terms of bend ing modes. For practical applications, these series must be stopped at some point. This truncation leads to errors in predicted response, and can sometimes predict stable behaviour when in fact the system is unstable. This phenome na has been examined by Balas, and the tendency of unmodeled modes to go uu stable when a control system is in place has been labeled by him "spill vet". Subsequent to his revelation of this problem, many cures for this ill have been proposed, most notably that, described by Aubrun in his paper on Low Authority Control. However now the first results from hardware experiments of flexible structure control laws are becoming available, and there is evidence that - 515- them luny bo other approxiin.it ion errors resulting from the inod.il ser/cf: trim cation. In order to corroborate these experimental discoveries, more? nerura-- Le means of calculating behaviour of distributed parameter systems must be devised. This paper shows a method for exactly evaluating closed loop or con trolled behaviour of flexible systems. This method is used both to demonstrate the established effects of splil- lover, and to show other problems associated with control systems designed with truncated modal series. These new problems suggest that in addition to problems with instability of tinmodeled or truncated modes, there may be equally serious problems with the prediction of the behaviour of the lower frequency rigid body modes. The exact method of evaluation can be used to quantify these low frequency disrre pancies, and to evaluate methods proposed to alleviate the problem. IAF-83-339 DYNAMIC MODELING OF FLEXIBLE SPACECRAFT : A GENERAL PROGRAM FOR SIMULATION AND CONTROL Dr L. PASSERON AEROSPATIALE FRANCE

The designers of future (and even already present) generation spa- cecraft will face two conflicting requirements : on one hand, the increasing capacity of spacecraft leads to size growth, thereby to mechanical flexibility ; on the other hand, demands on performances, more particularly pointing accuracy and mass saving are getting more severe. Therefore, a primary need exists for such adequate modeling of a large flexibLe spacecraft's dynamics as permits both behavior Simula- tion and control system design. This paper affords a tentative, dual answer to such need.

Firstly, a comprehensive dynamic modeling approach provides a ma- thematical model that enables simulation and prediction of behavior for any type of flexible mechanical system. Such systems are idealized as an assembly of flexible substructu- res. Each substructure is analyzed by finite-element techniques, and its deflections rendered as a conveniently truncated series of admis- sible functions. Introducing quasi-coordinates and vectorial quantities leads to a simpler expression of Lagrange's equations which now read as an implicit state-space representation : g(X,X,X) = M (X,X,U,P,A)

! h(X,X,P,t) = 0 (constraints) Respectively, X,U and P are the system state, input and seme parame- ters' vectors. The Lagrange's multipliers A account for constraint forces and torques. It should be stressed that the user can optionally express the vectors' components either in an inertial frame or in a triad relative to one of the system constituent bodies and that using, for each sub- structure, admissible instead of eigen-functions often produces more accurate eigenfunctions for the whole system.

Secondly, explicit analytical linearization of the above equations (1) around any type of nominal (or prescribed)system behavior permits stability analysis and derivation of control system criteria. -317 -

Such linearization leads to a classical state-space representation which makes it possible to : . assess the linearized model sensitivity to the various parame- ters/ . derive explicit analytical expressions of various transfer func- tions and conduct a qualitative study of system resonance properties, . study system observability and controllability properties. Last aspect is covered by a geometric approach that does away with computa- tion of the observability (resp. controllability) matrix and provides a straightforward characterization of the unobservable (resp. uncon- • J trollable) subspace.

As a concluding achievement, a design-aiding, global simulation software package was built. It carries out, among others, the follo- wing capabilities : . Time domain solution of the non-linear differential equations governing the system motion, . Explicit analytical linearization of the above equations around any nominal behavior (e.g. user-prescribed motion) of the system, . Assessment of the linearized model's sensitivity to the various parameters, . Time domain solution of the linearized differential equations, . Explicit analytical expressions of various transfer functions, . Appreciation of the system observability and controllability properties. - 318 -

IAF-8'3-140 ON THE CONTROLLABILITY AND CONTROL LAW DESIGN FOR

AN ORBITING LARGE FLEXIBLE ANTENNA SYSTEM*

Pel:IT M. Rainurn, A.S.S.R. Reddy, and R. Krishna Dept. of Mechanical Engineering, Howard University Washington, D.C. 20059, USA

Largo flexible orbiting systems have been proposed lor possi- ble use in communications, electronic orbital based mail systems, detection of earth resources, and in solar enetgy collection. For such systems both orientation and shape control will olden be re- qui red.

The Hoop/Column antenna system is under considerat ion for possible use in the future multi-beam Land Mobile Satellite Sys- tem (l.MSS) , designed to provide point to point communications for 2r)0.000 subscribers across the U.S. in the mid 1990's. The LMSS is based on a large geosynchronous relay antenna and a number of mobile, Earth-based receivers. To achieve the RF performance a pointing accuracy of f (0.03 - 0.10) degree RMS and a surface acruracy of (2 mm RMS will, be required. The Hoop/Column antenna, in orbital configuration, contains a deployable (telescoping) mast system connected to the hoop by support cables under tension. The desired shape of the RF reflective mesh is produced by a secondary drawing surface using surface control cables. The mesh is connected to the hoop by quartz or graphite stringers. . At one end oi the mast the electronic feed assemblies are positioned, whiTo.as at the other end are the principal solar arrays connected to the main bus based control.

Recently, graph theoretic techniques were used to study con- trollability of linear systems which could represent large flexi- ble orbiting systems with inherent damping. It was seen that the Iprw rank deficiency in the stiffness matrix dictates the required numbor as well as the location of the actuators required for con- trollability, whereas the presence of the damping matrix does not influence the required number of actuators but provides greater flexibility to the available, actuator locations for which the system is controllable.

It is the objective of this paper to apply these techniques, first to analyze the controllability of the Hoop/Column system

*Rcso.in:h supported by NASA Grant NSG-1414, Suppl. 5 based on possible arrangements of actuators, and, once controlla- bility is assured, to consider control law development. A recent treatment of the controls synthesis for this system was based on a model which contained three rigid-body rotational modes and a number of flexural modes, but ignored the three rigid translational modes. Actuators In the form of torquers only, were.assumed to be placed only along the mast assembly, and controllability was estab- lished indirectly through numerical means.

In the present paper, a finite element model of the Hoop/Col- umn system that includes all six rigid modes (with zero eigen- values) and the flexural modes is used. Combinations of point actuators and a torquer are assumed to be located along the mast, and at selected points in the feed assembly. In addition, a single point actuator is assumed to be positioned on one of the rigid links of the hoop assembly. To augment the term rank of the system stiffness matrix the effective control Influence matrix must have at least six linearly independent non-zero columns indicating that a minimum of six properly placed actuators are required for controllability. Once controllability has been established control law design is based on: 1) application of the linear regulator problem (LQG) from optimal control theory; and 2) pole allocation algorithms. In most cases simulated, surface torsion and feed mast torsion are among modes having the longest time constant. System transient performance is degraded significantly when the hoop actuator is not included, the LQG techniques offer more flexibility to the con- trols designer in attempting to meet performance and propeliant consumption requirements. Studies showing the effects of: 1) re- moving three of the rigid modes from the model; or 2) ignoring initial displacements in these modes, indicate overly optimistic results in terms of actual control system requirements.

1. Sullivan, M.R., "Maypole (Hoop/Column) Concept Development Pro- gram," Large Space Systems Technology-1981, Third Annual Tech- nical Review, NASA Langley Research Center, Nov. 16-19, 1981, NASA Conference Publication 2215, Part 2, pp. 503-550. 2. Reddy, A.S.S.R. and Bainum, P.M., "Controllability of Inherent- ly Damped Large Flexible Space Structures", 33rd IAF Congress. Paris, Sept. 27-Oct. 2, 1982, Paper No. IAF 82-319; to appear, Acta Astronautica. 3. Joshi, S.M., "Control System Synthesis for a Large Flexible Space Antenna," 33rd IAF Congress, Paris, Sept. 27-Oct. 2, 1982, Paper No. IAF 82-320. - 320-

IAP 83-341 Controllabilization and Observabilization of the Attitude Control System with the Flywheel Harumitsu Yamamoto .Jun-Ichi Aoyama Fumio Kaju Control Systems Development Deaprtment Space Development Division, NEC Corporation In designing the wheel control systems for the attitude control systems (ACS) of the 3-axis stabilized satellites, the conventional frequency-domain design approaches were mainly adopted in the past. However, due to the high accuracy requirements on the ACS and the necessity to con- trol the attitude of the large flexible spacecraft with the obscure flexible parameters, the adoptions of the more sophisticated design approaches utilizing the modern con- trol theories are increasingly proposed recently. Almost all the design approaches utilizing the modern con- trol theories require the controlled systems to be control- lable and to be observable. However, the attitude dynamic systems with the reaction torque generated by the flywheels are often not controllable nor observable. So, when the modern control theories are needed to be adopted, the in- tuitive countermeasure to take out the wheel angular veloci- ty from the system dynamics is often adopted. However this method can not be applied for the systems with the tacho- meter feed-back, which may be needed to meet the attitude stability requirements, due to the cross coupling between the dynamics of the main body and the wheel dynamics. The results of the examination on the control labiJiti^y and the observabilities of the each of the following four classes of the dydnamical systems with the angular obser- vation are shown first; 1) the rigid body with the flywheel, 2) the rigid body with the flywheel and the tacho- meter feed-back, 3) the rigid body with the flywheel and flexible appendage, and 4) the rigid body with the flywheel, tachometer fead back and flexible appendaue. Above examinations show that the system 1) and the system 5) are neither controllable nor observable and the system 2* and the :«ystem 4} are not controllable. - 321 -

The reasons why all of the systems are not controllable are made clear that the total angular momentum can not be con- trolled by using only the flywheel the internal angular momentum exchange actuator. And the reasons why the system 1} and the system 3) are not observable are that the total angular momentum of the systems without tachometer feed- back can not be observed only by the angular observation.

Then we propose the unified method to make the dynami- cal systems with the flywheel, both controllable and obser- vable. This method is first to make coordinate transfor- mation to make the total angular momentum to be expressed explicitly and then take it out from the system dynamics. This method which is derived by the physical interpretation on the dynamical systems is also derived utilizing the can- nonical decomposition theory of the modern system control theory. By using this method, the attitude control systems with flywheel can be designed via modern control theories even in the cases with the tachometer feed-back, which can not be done without this method. -322 -

IAF-O.j-.M2 ROTATORY MUTLON CP A RIGID BODY TJEAR UBHATIUN IOINT3. A*P. Mar-kef v .TnU-r«:ogiuo« Council, U33R Academy of tfoi.r.noes Problems concerning natural rnotlone of a vtirid body near libration points are actual today, >-apf;c i.nl.W -1 •**•-* to projects of utilization of li brat, ion jil3nl.=i. The rotatory motion of a ripid body aionp porio-Uc orbit close to triangular libratlon points in the cir- cular Tvatrict three bodypi^oblorn :i H ron3idor

IAF 83 - 346 MACS - THE ESA STANDARD FOR GUIDANCE/CONTROL AND ROBOTICS

R. HAVAS - J.C. COLDEFY - J. DAVID MATRA-SPACE DIVISION VELIZY FRANCE

ABSTRACT MACS (Modular Attitude Control System) is the generic name for the future on-board real-time oriented systems. Main application fields range from conventional attitude control systems (3 axes, dual-spin or multibody) to navigation systems implying rendez-vous and docking as well as configura- tion control of multibody systems like space stations or multi antenna systems. In order to reduce harnessing and connectics, improve test efficiency and first of all improve the real-time performance, a special purpose digital bus has been developped. This bus optimizes the real-time performance where other systems are oriented towards bit rate optimization. The MACS bus implements a multimaster type of access allowing each equip- ment or terminal to request at any time a communication ; the request may be serviced in times as short as 100 jisec. A wide spectrum of terminals is serviced by the bus : active or passive, intelligent or dumb, the inter- connection hardware penalty being minimal. This bus is going to be the European standard for attitude control, naviga- tion and robotics. The conference paper stresses how various points like security, noise immu- nity are solved and presents the bus key technical characteristics. Are presented as well the hardware and software architecture of ACE, which is the main subsystem processor connected to the MACS bus. Finally, the whole real-time subsystem architecture, implementing fault- tolerance features is presented. - 324 -

IAF 83-347 A SPACECRAFT DESIGN TOR SHIITTI r. by William H. Follett and Lawrence R. Greenwood Ball Aerospace Systems Division Boulder, CO USA The Earth Radiation Budget Satellite (ERBS) is an application research satellite that will study the components and dynamics of the Earth's radiation budget on a long-term, large-spatial scalp. Three scientific instruments will measure the solar constant, shortwave and longwave radiation, and stratospheric aerosols and ozone. Data thus collected will form the basis for extensive climatology models designed to predict long-term climate and weather trends. ERBS is the first spacecraft designed uniquely for use on the Space Transportation System (STS). While the basic spacecraft is compatible with launch on expendable vehicles the design was optimized for the shuttle to minimize orbiter bay length. This paper will describe that design and will emphasize the interface with the STS. The spacecraft consists of three major parts; the base module, the keel module and the instruments. The base module is 1X4 feet in cross section and spans the orbiter bay (15 feet) and mounts directly to the orbiter sills by trunnions. The keel module attaches to the bottom of the shuttle bay and houses the orbit adjust propulsion subsystem and is the support structure for the deployable solar array and antennas. Data collected by the scientific instruments and generated by the operational subsystems are processed by the command and data handling (C&DH) subsystem for real-time transmission by the communications subsystem or storage into four tape recorder units (TRU's) for later playback. The C&DH subsystem uses redundant, cross-strapped components with backup modes to eliminate single point failure. The communications subsystem interfaces with the C&DH sub- system. The subsystem includes two NASA TDRSS/GSTDN Standard Transponders and an electronically switched spherical array antenna (ESSA). The transponders detect and demodulate uplink commands, then route them to the C&DH. The transponders also accept and modulate signals from the C&DH for returnlink trans- mission. Two solar array panels generate electrical power that is then stored in two nickel-cadmium batteries. The subsystem includes a battery charge control unit and all switching necessary to control power to the users. An undervoltage switch automatically disconnects the nonessential bus should the primary bus drop below commanded levels. The undervoltage switch also includes an overcurrent monitor that detects nonessential bus current and automatically disconnects the load to protect the harness. Page 2 IAF-83-347 A Spacecraft Design for Shuttle

The thermal control subsystem uses A combination of active (heaters and louvers) and passive control components to maintain thp spacecraft operating temperature at 0 C to 30 C. The ERBS mounts directly to the Orbiter's cargo bay, usinq one keel and three longeron trunion fittings. An (Irbiter interface box (OIB) provides an electrical connection between the Orbiter's electrical and data systems and the spacecraft. The OIB contains the necessary circuitry for battery charging and interface con- ditioning. The Orbiter's remote manipulator system (RMS) deploys the spacecraft into a 300 km circular orbit. Several hours after separation from the RMS, the spacecraft's orbit adjust, propulsion system (OAPS) is fired for about 15 hours to raise the orbital altitude to 600 km. The OAPS is a low-i.hrust, monopropellant hydrazine unit. The attitude determination and control subsystem (AD(.S) maintains the spacecraft in the normal, nadir pointing niode or executes special pointing mode reorientation maneuvers. The momentum wheel spins about the spacecraft Y axis, providing pitch momentum bias.. Pitch attitude is maintained by slowing or accelerating the momentum wheel. When momentum wheel speed limits are reached, or precession of the momentum vector is required, electromagnetics are used to add or remove momentum. The economic use of the Space Transportation System requires new design approaches for spacecraft systems. The ERBS design is one that has many applications in that it can carry up to 1,000 Kg of payload and is compatible to TDRSS. A unique feature of the ERBS design is that the spacecraft requires no separate cradle or carrier and integrates directly into the STS. The spacecraft is scheduled for launch in m1d-1984 and will represent a major step in cost-effective space flight. - 326 - IAF

NEW APPROACHES TO PLANETARY EXPLORATION - SPACECRAFT/INFORMATION SYSTEMS DESIGN ~ by

A. V. Diaz Deputy Director, Solar System Exploration Division NASA Headquarters Washington. DC P0ri'»6 Marcia Neugebauer Manager, Mariner Mark II Study Project Jet Propulsion Laboratory Pasadena, CA 91109 J. Stuart Manager, Mars Geochemistry/Climatology Orblter Study Project Jet Propulsion Laboratory Pasadena, CA 91109 Richard B. Miller Manager, Information Systeme Program Jet Propulsion Laboratory Pasadena, CA 91109

ABSTRACT As a result of 3tudies undertaken during 1981 and 1982, in support of NASA's Solar 3y3tem Exploration Committee activities, aeveral new approaches have been identified for development of flight hardware as well as Rrouncl systems for the execution of U.S. planetary ml33ions through the close of the century. The proposed paper will summarize these new approaches for achieving cost effectiveness in planetary exploration in three different ways:

1. Use of modified "production line" spacecraft developed by aerospace companies for scientific and commercial use in earth orbit — study results will be discussed which demonstrate that with only modest modifications to existing earth orbiting spacecraft, excellent results can be expected at planetary targets in the inner solar system ranging from Venus to the inner portions of the asteroid belt. Use of both communications satellites typical of those used in geosynchronous applications, as well as low earth orbiting STientific and meteorological satellites will be discussed. The range of changes and the rationale for fchese changes required to perform planetary missions will be displayed in detail. - 327 -

?.. The development of a multi-mission modular type spacecraft for planetary missions — a new approach and new flexible spacecraft design proposed for development for planetary missions to comets, main-belt asteroids, and the outer planets will be identified. This Mariner Mark II spacecraft will enable reconfiguration at low co3t for adaptation to a wide range of missions. Design concepts which draw heavily on early planetary missions as well as technology developments that are expected to be available in the late 80*s and early 90's will be described in detail.

3. Development of low-cost multi-mission end-to-end information system — a system .design including spacecraft command and data handling system requirements, as well as an architecture for a cost effective multi-mission operations system will be described. This system is intended to be applied to both classes of spacecraft/missions described above. - 328 -

IAP-83-350

THE MATHEMATICAL MODEL FOR SPACE FLIGHT VISUAL SIMULATION DT COMPUTER GEHERAT3D IPIAOB Xα Lin Institute of Space Medico-Engineering Beijing, China

ABSTRACT It Iβ very necessary for astronauts to accept a lot of train- ing on the ground in flight simulators before their apace flight, In the training* one of the •Oβt important things is the real visual slnulation, for the real Moving scenes of stars relative to astronauts can give the* a real "spatlotemporal sensation" and help the* to determine their position and attitude in space. Aβ to the dynamic simulation of the scenes of stars, people u- sually n«e the following three practical means: a planetarium with control technique; a "celeetial-sphere model" with virtual Image generated technique; and the advanced technique of "compu- ter generated image". However, in all the three techniques * mathematical models must be established respectively.

In this paper, based on the scenes of stars seen by astro- nauts In their orbital flights, we have studied the mathematical model which must be v.amstructed for CCH system te realise the space flight visual simulation. Considering euoh factors as the revolution and rotation of the earth, exact date, time and site - 529 - of orbital insertion of spacecraft, as well as its orbital flight and attitude motion, etc., the author first defined all the ins- tantaneous lines of sight and visual fields of astronauts in space, and then, through a series of coordinate transforms, the pictures of the scenes of stars changing with time-space were photographed one by one mathematically. In the procedure of pro- cess, the author has designed a method of three-times "mathemat- ical cutting". Finally, we obtained each instantaneous picture of the scenes of stars observed by astronauts through the window of the cockpit* Also, the dynamic conditions shaded by the earth in the varying pictures of scenes of stars could be displayed.

The paper has built the mathematical model needed in the ap- plication of computer generated image to space flight visual sim- ulation. This mathematical model has been already simulated on computers for various flying programs. With the help of the Com- puter Application Institute of the Academy of Sciences of China, the real-time simulation experiment of the COT system has also been made. It turns out that the mathematical model Iβ completely right* So it can be provided for practical application. - 350 -

Ref.Nr. IAF-83-352 THE DEVELOPMENT OF LARGE ENVIRONMENTAL FACILITIES FOR SATELLITE TESTING IN EUROPE

by: J.F. Lafay & E.Classen - ESA/ESTEC A.Olivero - CNES E.von Platen - IABG The purpose of this paper 1s to review the development of large environmental facilities for satellite testing in Europe. Due to the increased size of satellites, large environmental facilities are required for testing complete satellites or large sub-systems such as struc*ire, solar panels. Why environmental testing of satellites? The aim of environmental testing is to ensure that the satellite will survive without any damage, the environmental conditions which are encountered during the launch phase and the life in orbit. Environmental testing is usually to be performed on several satellite models: - development models (structure and thermal) to check the validity of the mathematical models. - satellite prototype to check that environmental conditions can be sustained with margin. - flight models to check the quality of the workmanship. The main types of tests performed are: - structural testing; - thermal testing; - physical and mechanical testing; - electromagnetic compatibility and magnetic tests.; - specific tests. The organisation of environmental test facilities in Europe In Europe, environmental test facilities at satellite level are usually not available in industry due to the high investment and running costs vis I vis the number of satellites made by each company. Since the beginning of the European Space effort, environmental test facilities have been implemented in European and national centers. There are three general purpose environmental test centers in Europe: ESTEC in Noordwijk - the Netherlands; CNES/INTESPACE in Toulouse - France; IABG in Ottobrun - West Germany. -331-

In addition to these three general purpose environmental testing, a dedicated national center for optical calibration is implemented at l.A.L. in Li&ge Belgium. The four centers are the "so called" coordinated facilities in Europe. They are used for ESA programmes, national and European programmes, but can also be used for non-European programmes. ESA ensures a planning coordination function of these centers in order to make the most efficient use of them. The development of new environmental test facilities in Europe Two main factors are influencing the development of new environ- mental test facilities in Europe: - the increased size of satellites of Ariane 3 and 4 class, or US shuttle class - the tendency for the centers to be able to fully test large satellites in the most economical way. A description of the main existing and in development environmental facilities in the three centers is given. The main facilities in development are: at ESTEC - transformation of a Dynamic Test Chamber in a solar simulation chamber. 0 sun 6 m; - an electrodynamic multishaker 2 x 14 T. at CNES - a large acoustic chamber 'at IABG - enlargement of a solar simulation chamber 0 sun 3.4 m; - an electrodynamic multishaker 4 x 7 T. The future for larger satellites environmental testing The size of environmental test facilities cannot be increased significantly beyond what is now in development. The investment and running costs would become prohibitive. Modular testing will become soon necessary. Investigation and experimentation are performed in Europe in this field. -322 -

IAF - 83 - 355

NEW GENERATION OF INFRARED HORIZON SCANNING SENSOR FOR LOW ALTITUDE SPACECRAFT

by R. SERRADEIL, A. de DIANOUS, M. HEBERT SODERN 1, avenue Descartes 94450 LIMEIL-BREVANNES (Prance)

The STD 12 infrared horizon-scanning sensor developed by the French firm SODERN, is designed for attitude control, with respect to the Earth, of three-axis stabilized satellites in low orbits (600 to 1200 km). The operating accuracy is better than 0.1". Two STD \2 sensors will fly on-board SPOT', the French observation satellite due for launching in 1984. 1 - Operating principle The main feature of the SODERN STD 12 Earth infrared horizon sensor is to provide two traces with one sensor. With two different analyzing beams the misalignments around pitch and roll axes are measured without ambiguity, the satellite altitude knowledge not being requested, but such an operation mode usually requires two sensors. In addition, the sensor accuracy is increased, some errors being compensated. The geometrical path of the analysing beam axis is a 60* half-angle cone, having its axis in a direction opposite to the geocentric direction (at null misalignment) (see figure 1A). lhts primary scanning cone is intercepted by two mirrors, syme- trically 45 tilted with respect to the cone axis and being a part of the sensor structure. The primary cone is then transformed into two half- cones having their axes in two opposite directions, perpendicu- larly to the primary cone axis. The sensor is set on-board the satellite so that the two half-cone axes are perpendicular to the orbit plane. The plane containing the two half-oone axes and the primary cone axis include the geocentric direction, at null misalignment. - 335 -

The resulting traces on the Earth are drawn on figure

^Scanning 1

—- Pitch axis

Subsatellite Scanning trace 2X Eartl) limt> point

An angular magnetic encoder, bound to the scanning mechanism, measures digitally, with a convenient resolution, the angle between the analysing beam and a reference bound to the sensor structure, hence to the satellite reference axes. The Space to Earth or Earth to Space infrared radiance transitions are detected and their position are quoted 'f j,Vf>2 for the first half-cone, vfl 1,^*2 f°*tn e second half-cone. By combination of these four angles, the pitch and roll angles may be determined.

2 - Sensor description The STD 12 sensor is made of : - an optical head including scanning mechanism, detector, optical components and electronic circuits which must be located in the immediate vicinity of the foresaid components, - an electronics unit which processed signal and drives the scanning mechanism.

3 - Sensor performances The paper will present the results of qualification tests performed on the proto-flight model and the status of the on-going life test (the sensor is designed for an operating life time higher than 3 years). - 334 -

IAF-B3--356

A Hl«H POWER RETRACTABLE SOLAR ARRAY FOR FUTURE SPACE MISSIONS

by H. Borduas*, «.W. Marks*, E. Quittner*, .I.T. Rpushall* and S. Ahmed** *Spar Aerospace Limited, Toronto, Canada **Department of Communications, Ottawa, Canada

ABSTRACT Solar arrays that utilise a tens toned flexible substrate to -support the solar cells?, folded accordion-fashion In foi stations and high-power communications satellites. Array partial deployment and/or partial retraction are emerqitvi ap requirements when on-orb it maneuvers of significant- accelerations must be executed while some array power generation is maintained. The advent, of the Spare Transportation System (STS) has also created the need foi full array retraction and restowage capabilities, requiring the stowed sub-system to withstand loads associated with docking, change-out, re-entry and landing of the STS.

Spar Aerospace, together with the Canadian Department of Communications, has in the last decade developed deployable solar array designs applicable to future space miss inns starting with the (Communications Technology Satellite) array of approximately 1 kW (end-of-ini ssion) power. The Hermes type design was subsequently evolved into the high-power, modular, L-SAT array of approximately 2 to 8 kW (erid-of-10 year mission) power. The L-SAT is the European Space Agency's Large communications satellite platform which is expected to be launched in 1986. This paper presents the further logical evolution towards future high-power, retractable, muiti-mission arrays. The design approach is aimed at evolving from the modular L-SAT array a generic retractable array design. This design is represented by a typical segment of a future array. Such a segment is defined as a full length portion of an array of sufficient width to incorporate all the essential features of the complete array, i.e. those of power generation, stowage, partial and full deployment, tensioning, partial and full retraction and re-deployment. Different power levels can be achieved by using a single segment or more, coupled, segments, by scaling the dimensions of a segment or by a combination of both approaches.

By these means the same generic design can be utilised over an exceptionally wide range of power levels, as well as, being adaptable to different spacecraft and launch vehicles. Conceptual designs for specific applications demonstrating different combinations of segment integration are presented. These designs illustrate the growth potential of the basic design from 1.5 kW to 25.0 kW (beginning-of-mission) power per array wing. Along with the design concepts, an analysis and test verification plan is presented. This plan addresses the design verification of array stowage, release and restowage, as well as, that of deployment, tensioning and retraction. - 536 -

Ref.number: IAF-83-357

HEAT RESISTANT EXPLOSIVES PRODUCED IN HUNGARY WITH POPRIPLE SPACE APPLICATIONS

Gy. BENC7. a and J. DERES b a/ Superintendence for Chemical and Explosives Industry, Budapest, Banyaleg utca, H-1225, Hungary b/ National Trust of Petroleum and Gas Industry, Budapest, Schttnherz 55. utca 18, H-llll, Hungary

Of late years special explosives used in space technology and rocketry /Apollo missions, Space Shuttle Program, Trident/ have been gaining an increasing attention. The requirements put against these materials include high values of heat and cold resistance, insensibility to radioactive radiations, high bri-- sance, high sensitivity to initiation and permissibility. Tfie.se requirements are met only by a very limited number of explopi*'es, of which hexanitrostilbene /HNS/ is the most widely used one.

HNS has been produced in Hungary for morn than ten years. The procedure of its synthesis patented by us is simple *-md economical. The HNS is used for producing blasting caps, deto- nating cords and lined shaped charges which fulfil the tvquiie- ments of high depth oil exploration up to a temperature of 240 °c, To meet the requirements of an even higher heat resistance, a new type of explosive has been developed that is used to produce explosive hardware which is applicable safely even at a temperature? of 300 °C. In the paper procedures for the production of these two ma- terials are outlined together with the fundamental chemical and explosion-physical characteristics of the fully manufactured products. In addition, questions raised in the United states in connection with the examination of the Hungarian method of HNS production are also discussed. - 537 -

IAF-83-358 Some Dynamical Design Considerations for Momentum Biased Spacecraft Ramasamy Gounder Seliappan RCA American Communications, Inc Princeton, NJ, USA

This paper discusses some of the dynamical aspects that affect the attitude behavior of a spacecraft placed 1n a near earth polar orbit. The parameters such as atmospheric density variation, superrotation of upper atmosphere, pitch equilibrium angle, and trim boom length selection to reduce nutation are considered. These parameters are studied with reference to two momentum biased satell1tes(Magsat and Dynamics Explorer-2) and the analyses are correlated with observed flight data. It 1s found that the design model of certain parameters has to be Improved by Including other phenomena so that flight data and the analytical model predictions have good correlations. The effects of mass Imbalance on the orbital and nutational modes of the spacecraft attitude are discussed. The general equations of motion of a momentum biased spacecraft, having products of Inertia and placed In an elliptical orbit, are derived. The external torques consisting of aerodynamic, gravity gradient, and residual magnetic dipole are assumed to act on the spacecraft. The effect of superrotation of the upper atmosphere Is Included. The torque due to solar pressure 1s assumed to be negligible. The equilibrium positions of the attitude, as a function of mission lifetime, are obtained In closed form. By approximating the linearized equations, closed form solutions for roll-yaw angles are obtained. A coordinate transformation 1s used to express the spacecraft roll-yaw motion In terms of right ascension and declination of the momentum vector relative to the negative orbit normal. The total motion consists of a tansient part and a steady state part. The transient part of the long term 1s damped by the yaw gravity gradient torque. This 1s produced by the product of Inertia and Is termed as "drift damper" 1n this paper. A control strategy for the length of a pitch axis boom to be used as an aerodynamic trim surface that would minimize the application of magnetic control torques has been developed. The analyses developed has been applied to Magsat and Dynamics Explorer-2 missions. - 338 -

1AF H3 - 3blJ

GlfIDANCL AND ATTITUDE CONTROL DURING THE HNAl. APPROACH OF AN AUTONOMOUS

RENDEZ-VOtIS

B. GOVIN W. FF.HSK .I.L. LACOMBL MATRA-SPACl DIVISION ESA/ESTEC VEIIZY-fRANCE NOORDWI,IK HOLLAND

= * -4 = + =••=+•=•» =+=+^+=+= + =+-•+ =

ABSTRACJ This paper describes and analyses the automatic docking in orbit, between a chaser satellite and a "passively cooperative" target which is stabilized in aitit'.'do but does not maneuver during this operation. Several model missions are first identified ; the main features which impact on the final approach conditions, such as target orbit, target attitude, docking line orientation, ground visibility... are underlined. Then, after an overview of the RVD phases, only the final approach is ana- lysed in detail because it is the more demanding on autonomy for the chaser. This phase is characterized by the fact that the target cannot be treated as a point ; its attitude must be considered. Moreover, the small separation between the two vehicles and the short time involved in this phase makes the differential effect of gravity negligible. Final approach subphases are then identified ; basically there are two sub- phases respectively for docking line acquisition and for acquisition of correct kinematic conditions at impact. However, depending on docking reqti - rements, a third subphase may be introduced for a fine adjustment of these kinematic conditions. Then, guidance and attitude control strategies are selected for each subphase to minimize important requirements such as sensor field of view and control thrust distribution. Control laws are also briefly indicated. A set of requirements for guidance instrumentation is then derived starting from the conditions at coupling. Need of direct relative attitude is discussed. -339 -

The last part of the paper describes a tentative concept of a Rendez-vous and Docking (RVO) sub-system. Control modes of the chaser are defined and a set of equipment 1s proposed. In this concept, attitude control and RVD sub-systems are unified and use the same processing facilities. TAF-8 3-360 Design and Development of a SAH Antenna A. Fuentes/J. Iglesias CASA Space Division, Madrid, Spain

One of the most challenging technology aspects of this decade within the space research is earth resources observation. The remote sensing is performed by some pay- load eLements, among which the Synthetic Apertut? Radar is, perhaps, the most complex one due to the stringent anten- na requirements.

An example of this antenna can be found in the ame- rican SEASAT in which the microstrip technology was ap- plied.

The European Space Agency has sponsored a programme that enables the space industry to develop a wavequide technology applicable to this antenna.

Within this frame work, CASA has carried out a study to demonstrate the feasibility of large, high stability, flat deployable antennae for a direct application for a synthetic aperture radar. The study comprises configura- tion studies of the overall antenna, as well as the design, manufacturing and testing of the most representative parts of it.

The paper describes the trade off performed, the configuration selected, the hardware developed and the test data obtained. IAF-83-361 A LARGE DEPLOYABLE ANTENNA STRUCTURE FOR THE ERS-1 SATELLITE R.A. Karsten (DFVLR), R. Wagner (Dornier System GmbH), M. Westphal (Dornier System GmbH)

The slotted waveguide array antenna has been chosen for the C-band SAR to be flown on the first ESA Remote Sensing Sa- tellite ERS-1. This antenna type provides high aperture efficiency and good pattern control with a flat, easily fol- dable structure of high stiffness.

The use of carbon fibre reinforced plastic (CFRP) material as proposed in early studies further enhances the mecha- nical properties: high stiffness and thermal stability are realized with a very lightweight structure. The aperture dimensions of 10 m x 1 m call for a deployable configura- tion. The antenna is thus divided into 5 mechanical panels which are reinforced by a deployable truss structure. The latter assists the deployment process. It provides very high mechanical stiffness and alignment accuracy at mini- mum mass and volume penalty.

The technological problems involved in this antenna design called for a pre-development effort. The programme was first sponsored by DFVLR as a contribution to ESA, and la- ter joined by the Swedish Space Corporation. The work is performed by Dornier System (Germany) for the mechanical aspects, and ERICSSON (Sweden) for the electrical aspects. The programme is now at an advanced stage and the results available have served as input to the definition of the ERS-1 system.

The design of the antenna structure is determined by the following requirements: - high stifffness, high alignment accuracy, low thermal deformation in orbit; - high stiffness, high package density for launch.

The evolved concept represents the optimized results of the combined efforts in structural design, materials selec- tion, and mechanisms lay-out: - The truss structure has been chosen to provide high stiffness and leverage for accurate alignment at minimum weight. The configuration has been optimized w.r.t. structural and deployment kinematics requirements. - The CFRP material allows control of thermal deformation in spite of the structural depth and the resulting ther- mal gradients. It is used for all structural and electri- cal parts (waveguides) in the antenna. - 342 -

- The hinges and mechanisms provide play-free joints fm xt cure alignment, ah low friction for smooth deployment uir low latching impacts.

The structure design fully utilizes the inherent st. Jffn»:sK of the antenna panels which results from the radialInq pig ments and the distribution system. The deployabl*- truss configuration is based on structural interaction with Hiis bending stiffness. It therefore does not require* highly sophisticated elements. Few foldable bars are; needed. The folding hinges are designed to include the functions "I deployment and locking in a most simple fashion.

The CFRP material has been optimized towards the require ments for the waveguides. A laminate of high mechanical stiffness (E = 13OOOO N/mm2) and high thermal stability (c.t.e.o

Ball bearings are used for all hinges. They are generally pre-loaded to avoid play, and arranged in redundant con- figurations. The deployment is achieved in a succession «4 steps. Drive units are springs for the less sensitive mo- tions. DC motors are employed where latching impacts hav^ to be avoided.

The development has progressed to the manufacturing and functional testing of a full scale 3-panel functional modil including deployment testing with gravity compensation. IAP-83-362 THERMAL FATIGUE IN THE COMPONENTS OP FLYING VEHICLES ENGINES G.S, Pisarenko, G.N, Tretyachenko, L.V. Kravchuk Intercoamoe Council, USSR Academy of Sciences Drastic cyclic temperature changes is a eharacterie-- tic feature of the flying vehicles engines operation conditions* These tempera t'ure changes induce high thermal stresses that cause untimely fracture of the material. Insignificant variation in the heat exchange boundary conditionsJjjSroduce a conaiderable change in the tem- perature level at wiiich an extreme stress—state is obser- ved. Since lifetime of the material depends on both stress o.nd temperature that change during n cycle accer- ding to different laws, the strength criterion should be a function of these bwo parameters at least. The paper presents the analysis of non-coincidence in time of temperature and stress extreme values of cha- racteristic components. The way is shown in which this process can be controlled under laboratory conditions simulating the operation of actual components. The ex- perimental set-ups are described which arc used for studjiing thermal fatique of materials that function undor conditions of non—uniform thermal and stressed state. The authors formulated strength criteria and the approa- ches to the establishment of the equations of state for the materials operating under the conditions mentioned. The way is shown in which the influence of an aggressive environment upon the lifetime of materials may be taken into accouint. The suggested methods of testing and cal- culation can be used for designing engines components subjected to cyclic changes of temperature. IAF-83-367 EXPERIMENTAL AND THEORETICAL BURNING OF SOLID ROCKET PROPELLANTS NEAR PRESSURE DEFLAGRATION LIMIT

by

C. Bruno, G. Riva, C. Zanotti, R. Donde, C. Grimaldi, and L. De Luca

Dipartimento di Energetica - CNPM, Politecnico di Milano, 32 Piazza Leonardo da Vinci, 20133 Milano, Italy. - Phone: (02) - 2364582/2364215/2362678. Telex: 333467 POLIMI-I.

Combustion of solid rocket propellents near the pres- sure deflagration limit is of particular interest both for its technological and theoretical importance. In problems of low pressure ignition, programmed extinction, and re- ignition, knowledge of the pressure deflagration limit is essential for the success of the mission. Theoretically, it is usually accepted, but unproved, that pressure deflagra- tion limit means lack of steady state solution for the burning rate eigenvalue due to excessive heat loss. Anyone can immediately check, as reported in few papers, that or- ders of magnitude exist between the computed and the requi- red heat loss necessary to obtain actual values of pressure deflagration limit. This research group has set forth a general nonlinear theory of burning stability, which also predicts the exi- stence of the pressure deflagration limit due not to lack of steady state solution but to burning stability. Analy- tical predictions account for heat losses, variable thermal properties and distributed chemical reactions in the con- densed phase, external radiant flux, different ambient tem- perature, different pyrolysis laws, different flame models. Numerical integration confirms and defines the validity of the analytical predictions under a variety of operating conditions. Experimentation in this marginal burning domain is particularly delicate. For example, it was necessary to set up a new experimental technique.capable to measure steady burning rate down to pressure deflagration limit without perturbing the combustion wave. It is a laser-based optical technique applicable to both noncatalyzed double-base and nonmetallized ammonium perchlorate-based composite propel- lants. Extension to other propellents should also be possi- ble. Likewise, it was found appropriate to establish the value of the pressure deflagration limit by slowly decrea- sing the burning pressure rather than increasing the igni- tion pressure. Both procedures offer disadvantages, but the former avoids the burning dynamics associated with ignition transients. A special phenomenon related to the pressure deflagra- tion limit is self-sustained oscillatory burning. This is predicted analytically, verified Numerically, and observed experimentally. Oscillatory burning was observed in the past by other investigators as well, in particular in USSR and Japan. However/ to the best of our knowledge, no sati- sfactory explanation of either the pressure deflagration limit or self-sustained oscillatory burning can be found in literature. In this paper.a unifying interpretation of both phenomena is offered, together with numerical and experi- mental validations. A further effect, probably again related to the pres- sure deflagration limit, is spinning burning. This was ob- served experimentally, but, being of multidimensional na- ture, lies outside the validity limits of the theoretical approach. However, work in this direction will also be performed. IAF-83-368 Effect of Erosive Burning on Pressure and Temperature Sensitivity J.R. Osborn, Purdue University, West Lafayette, IN 47907, USA J.M. Murphy, Martin Marietta Aerospace, Denver, CO 80201, USA J.P. Renie, Purdue University, West Lafayette, IN 47907, USA Requirements for high propellent loading in solid rocket motors have led to low port-to-throat ratios resulting in high velocities of the combustion gases flowing across the burning surfaces in the aft region of the rocket. The effects are critical since erosive burning strongly influences the performance level and the performance repeatability of the propulsion system. In that regard, there are two factors, temperature and pressure sensitivity, that need to be examined with respect to the effect of erosive burning. Theoretical and experimental studies were conducted on ammonium perchiorate based composite propel1ants to evaluate the effect of erosive burning on the above two factors. The theoretical erosive burn- ing rate model couples a statistical non-erosive combustion model, the Petite Ensemble Model, with an approximate boundary layer analysis for flow over a transpiring surface so that the effects of crossflow velocity, base burning rate, pressure, and surface roughness on the erosive burning sensitivity of an AP based composite solid propellent can be predicted. The theoretical erosive burning model is based on the hypothesis that the erosive burning effect is due to an increase in the value of the transport properties in the gas phase reaction zone caused by the presence of a turbulent boundary layer. The theoretical results indicate that burning rate, pressure exponent and temperature sensitivity may be materially affected as the crossflow velocity is increased depending upon the oxidizer particle size. Below a particle size of about 10 microns, the results show that these combustion parameters remain relatively unchanged as the crossflow velocity is Increased. Above this particle size, an Increase in the crossflow velocity causes substantial increases In both the propellent burning rate and the pressure exponent. At the same time, decreased temperature sensitivity results for Increased crossflow velocities with propellents having the larger oxidizer particles. The experimental study was conducted in a special device consisting of a gas generator and a two dimensional test section in which propel1 ant slabs were placed so that the erosive burning measurements could be made. The mass flow of propellent gases 1n the gas generator was an order of magnitude larger than the mass flow of propellent gases added 1n the test section. The crossflow velocity was determined by selecting the ratio of the flow cross sectional area in the test section to the - 347 - exit throat area. Velocities obtained in the test section were In the range of from 700 to 1000 meters per second. The static pressure in the test section ranged from 2.75 to 4.13 MPa. The test section propellent Initial temperatures were conditioned to values of 247K, 289K and 31IK. The propellant burned was a 65 percent AP/17 percent aluminum composite propellant. The experimental results, erosive burning, exponent and temperature sensitivity for this propellent agree with the trends predicted by the theory. IAP-83-369

STUDIES ON COMPOSITE EXTRUDABLE PROPELLANT WITH VARIED BURNING RATE PRESSURE INDEX* n*

T.L* Varghese, RΒ. Muthiah, John David, A.J, Kurian S.K. Athlthan, V.N. Krlshnamurthy and M.R, Kurup

Propellents and Chemicals Group Vikram Sarabhai Space Centre

Trlvandrum-695 022fIndia.

Abstract

Extrusion of single and multi base propellents has been in vogue for quite some time but extrusion of compo- site propellant is an advanced and latest entry in the modern solid propellant industry* This paper discusses the development of composite propellant extrusion technique and the study of burning rate pressure indices (*n*) with respect to compositional variations* The *n* is found to vary from 'mesa* to plateau and plateau to 0*35 by suitable compositional modifications* This propellant is based on ISRO-CTPB binder using ISRO-AP as the oxidizer. AP parti- cle size variation and inclusion of additives like PVC. lead stearate, ammonium sulphate, lithium fluoride etc. are found to Influence the burning rate pressure index *n*. These low smoke non-alumlnised extrudable composite prope- llants find application in special purpose motors like air- craft pilot seat ejection cartridge, engine starters etc. - 349 -

REFERENCE WO. IAF - 83 - 370 TETRACHLORO PHTHALIC ANHYDRIDE BASED CHLOROPOLYESTERS FOR INHIBITION OF DOUBLE BASE ROCKET PROPELLANTS.

JP AGRAWAL AND KS KULKARNI EXPLOSIVES RESEARCH AND DEVELOPMENT LABORATORY, PASHAN, PUNE - 411021 ( INDIA )

The choice of inhibiting materials for double base and composite modified double base rocket propellents has always been a difficult problem because of the presence of nitroglycerine in these propellants and its subsequent migration from the propellant towards the inhibitor. The inhibition of double base rocket propellants with unsaturated polyesters has become popular in recent years, but they usually suffer from the drawback of high nitroglycerine absorption. This may bo considerably lowered by exploiting the concept of introduction of electron acceptance sites in one of the components used for the synthesis of unsaturated polyesters. Chloropolyester-1(CP-1) based on tetrachloro- phthalic anhydride (TCPAn), propylene glycol (PG) and maleic anhydride (MAn) and chloropolyester-2 (CP-2) based on TCPAn, polyethylene glycol mol. wt. 200 (PEG-200) and MAn have been synthesised and characterised for gel time, exotherm peak temperature, tensile strength, % elongation, water absorption, nitroglycerine absorption,vheat resistarce and flame retardance. The blends of CP-1 and CP-2 designated as CPB-2 (CP-1 : CP-2 t t 20 t 80), CPB-4, CPB-6 and CPB-8 have also been formulated and characte- rised for these properties. Based on the data for various characteristics, CPB-4 has been selected for inhibition and static evaluation of rocket propellents. The double base rocket propellant sustalners containing 2-NDPA have been inhibited with CPB-4 without the application of any barrier coat and statically fired at ambient, cold (-40°C) and hot (+50eC) temperatures. The pressure- time profiles were found to be smooth and flat in all cases, inferring that the CPB-4 inhibition system (with- out application of any barrier coat) is working satisfactorily. - 350 - IAF-83-372 Study of Sudden Expansion Injection for Propulsion Applications

Y. Levy and Y.M. Timnat Department of Aeronautical Engineering Technion - Israel Institute of Technology Haifa, Israel.

Sudden expansion, first utilized to stabilize flames in the late fifties, can be applied to propulsion devices, in particular dump combustors, which are used in subsonic and supersonic ramjets. The present work Investigates the Influence of the injection pattern, as affected by geometry and pressure, on combustion efficiency and stability. To achieve th-is goal the fluid velocity 1s measured and the evolution of the droplet diameter Is followed. This requires an analysis of the two-phase flowfield within the combustor. Gas flow pattern and droplet size distribution, concentration and velocities are strongly affected by the operating condition, such as Inlet air conditions, combustor geometry and fuel injection systems and relate directly to combustion efficiency and stability. Gas flow inside cold dump combustors has already been investigated. There is, however, not much information about the real two phase flow in operating combustors. In order to gain Information about the flow, an experimental system was set up. It consists of a sudden expansion combustor with facilities for changing operational parameters such as the fuel injection system (injector type, fuel, pressure and fuel temperature) the expansion ratio, D/d, the slenue^ness ratio, L/0 and the flow rates. Transparent windows were Installed to allow for optical measurements Inside the combustor. In order to perform gas and fuel droplets flowfield measurements, a suitable Laser Doppler Anemometer system (LDA) was built. The system Is capable of measuring simultaneously droplet velocity and size. The gas flow 1s represented by micron size tracking particles. The droplet size measurement 1s based on the relation between the droplet's diameter and the pedestal amplitude of the detected signals. Each particle scatters a burst of light as it crosses the LDA control volume. The light intensity oscillations within a burst (the Doppler frequency) are linearly related to the particle velocity while the maximum of a DC component of the burst amplitude, as detected by the photomultiplier 1s related to the droplet diameter. A nearly linear relation exists between the pedestal amplitude and the diameter of transparent spherical particles 1n the range of about 30 to 500 ym, which is of Interest for the present study. Calibration 1s required due to the sensitivity to many operating conditions (beam Intensity, photomultiplier high voltage supply, amplifier gain settings, window attenuation, etc.). In order to perform the pedestal amplitude measurements, a peak detector unit was built, which can record the maximum amplitude of a signal within a specified gate time. Calibration 1s performed with the aid of a special unit which produces a train of fine droplets in a specified direction and can be operated Inside the combustor, taking Into account the influence of the transparent windows. - 351 -

The pedestal amplitude signals and the Doppler frequency as processed by a DISA counter are both connected to an A/D converter Interfaced to a mini computer. Sequential sampling of pedestal and Doppler analogue signals enables, with the aid of suitable software, to record pairs of relevant Information (frequency and pedestal amplitude) for each measured particle. The system is fully automated and allows to record large samples to reduce statistical errors. The experimental procedure starts with cold tests during which the Influence of Inlet flow conditions and fuel injection parameters on the flowfield of the gas and the fuel droplets in the combustor Is analyzed. Droplet size distribution and concentration are also measured. The second stage in the experimental procedure will Include performance of similar studies during combustion. The hot flow measurements allow to relate various operating conditions and thus the two-phase flowfield pattern with the combustion efficiency and its stability, supplying essential information to dump combustor designers. - 352 -

1ECH1L1A.R1T1ES OF START REGIME ORGANIZATION Til S'J'A JK COMBUSTION CYCLE LIQUID ROOKET ENGINES V.M. Kalnin, V.A# SheratSannikov Intercosmos Council, USSR Academy of

The organisation of start process prefiro period in .liquid rocket engine with utilization of prelmner ?;BS from turbine in combustion chamber is obsorve'l. The pe- nults of hydrodynamic **nd ma thematic modelling of rea] engine prcfire proceseee considerably Influencjjig

IAP-83-374 SIMULATION OP THE STARTING PROCESS IN PUMPING SYSTEMS, PEEDING THE LIQUID ROCKET ENGINES OP 3IAOE VEHICLES Ovsjaniiikov B.V., firshov U.S., Cherv&kov V,V. Intercoainoa Council, USSR Academy of Sciences A mathematical model of a pumping ayatern, feeding the liquid rocket engine is considered. The boundary conditions are defined. An analyaia of operating con- ditions of the pump in the process of the engine start up is carried out. The characteristics modes of the pump operation before and after the combustion chamber ignition are singled out. Criterial complexes, which characterize identity of transient processes In the propellent supply system of liquid rocket engines, are derived on the basis of the mathematical model. An analysis of the obtained criterial complexes is carried out. For the first time it is shown that In the process of mathematical simulation of transition to lower speed the run-up time of the pump must be inc- reased in inverse proportion to the decrease of its r.p.m. The generalization of experimental data on the basis of the obtained criteria made it possible to define the mathematical model of the powerplant mor«5 accura- tely. IAF-8%576 FULLY REUSABLE LAU1K3H VBH1CLB WITH AIRBRBATHINO BOOSTER Huang Ztt-Wei System Engineer, Chinese Academy of Space Technology, Member AIAA

ABSTRACT Results of a preliminary study of a two-stage fully reusable launch vehicle concept are reported. The first stage is a hydrocarbon/hydrogen fueled air breath- ing hypersonic aircraft, and the second stage is a modified spaee shuttle orbiter. The purpose of this study is to analyse the performance of such system, and make eonparision between two options for the first stage. One option is a turbojet/soraajet powored, horleental take- off (HTO) and landing first stage, the other is turbojet powered first stage also with HTO capability. The analysis is based on the computer synthesis for one nor- mlnal mission specification and for the same payload capability. The paper will describe the system in brief, explain the methods used and show the reemlte. More emphasis are pat on the minimum fuel profile of the first stage flight. The results of the study suggests that the turbo/scramJet booster has potentially a muoh lower gross weight ( approximately v 24 percent lower ) thmn turbojet option. Twelve references and eleven figures are included in this paper. Some parts of thic study were finished in Spec* System laboratory, NIT* - 555 -

IAF - t^ - 377 OiTlLIT/iATTON O¥ THH PK0HJU.1 OM h'OR f.rlKTEORCXMnAT, I'ROBFS Jiotr Wolcinskl Technical University of V-.-jraow, Warsaw, Poland Tho objective of this work ii; to make the optimization calcul.ition of the powor unit of tho meteorogioal probe, which serves to bring tho 5 kg of useful load up to the speed of 1000 m/s at' the altitude of 20 kin, Tlie power unit of the probe consists of a rocket booster constltu- tins the first stage of the probe, and tho rr,m,jat ongino, which drives the second stage. The rocket booster works on the common rocket propfi.li.int ivhila tiiQ ram jot engine works on aolid fuel. The optimization analysis of the power distribution between each stage of the metoorogical probo vine carried out in tho course of the research. Three car.ea worn con- sidered within the folloiving framework: the firat stage TiCceleratcs the prnbo uj> the spood of respectively 1«5 Mt 2 M, 2.5 M and the task o£ thn ramjot at nee is to roach the required final speed at tho altitude oX' 20 kni. In the first approximation, the altitude at which the ramjet atage starts its operation was defined for constant accoloraLions of the rocltot booster. Then the approximate calculation of the ramjet sta^e opcrtitjon was made. The calculation aimed at defining tlio amount of thn fuel demand neeeo.so.rj1 to achiovo tho required flight pro- file. The calculation was worked out for the three as- sumed cases of the probe flight. In the calculation of the ramjet ongino operation parameters the following assumptions v/ere made. The inlet d.iffuser is a diffuser of a constant geometry operating in the Gjsbom of two shock waves: oblique wave and a nor- mal shock wave. The flow within tho combustion chamber goes on with the speed less than 150 m/s. Tho outlet nozzle has a fixed cross-section. The calculation based on the standard atmosphere tfafca* To cariv out the calculation tho fuel parameters ela- borated l\y T. Li twin et al.fi] were uv,eO. and the aexo- d;yn?imic drag ratio was taken from Zucrow [2]* The required flight profile was assumed to make the first approximate calculation ot the ramjet engine operation parameters (in all of the three cases). For such a trajectory and the constant probe weight (in the first approximation the change in the probe mass duo to the fuel combustion was ignored) the required fuel consumption was calculated which .yielded the first approximation of the - 356 -

V'MJU ' T'id fnril (•'Jjjfjiiii;: nr. <:iim;t.ant "cjui VM Ian r-ttjo -iM<\ h-'iVinj; <;ons; id«ron Uin dfTiniU? fun.l ; from Lbr? n^r.uvu-d |-.nin orujjjj-jj'r.-iJ, hui .')!ul tho in CfiMwry i'unl wasr, do fined i-'irl ior) wm1. --*; ?J5»IIHI -»I Mini < h'i f.lif;hfc jM'oJ'iLc I hn I t ho jjuli- •n;'lij«»;jnt }"U).>-1 ••)ji|'.rnxi i.'i-i i. i on .snrVod tn nb!.:.'ij) I h" !."•.:•- l;in/r <»r?I(julfiLi on uf f-hc- VdcUot boon tor fjt,!)(;;n (of n unii.'i- ('jni Ihru.'jt-j ,'Ui'l flin ]"iiii,jol. alui-;f- wM.Jj Iho tjonf if;Mr:i!.' on dcf'iuod "m tlio. ji?'oviou<; 'i; nroxurfjiion, 11 w;>.f5 ffi'-ohUtjhi'ti {'(-•r f.li1: cuios und'rr oynnii mi!, i mi flrjt. ilie o].lt!nuJ!i m.-iMs ie ob'?iirifyd vvlusn i-lsn »nil. hi brought up l-o tho aper-d {if ~\»{j M b,,' lnc.'inrj oj* -\ vacA'.'il '.'ji(;itio, Tho j>robo it.acJf .in I'Ainh ,') liJiii, I'^-'HihoH ilic ojxjeid of 1 lun/H nf. t.li*? nli:jt.ufk' of .'.' km. If i.\\o. boofil.or brhi,';n uj» t)\", unit f-o f-.vp.iii-tir fij'fiod, i:11r; HIM:.;;? of I.Jio »mtiro ]irobo increases, ?mrl in thf tj-'jjio nf .•u.:(2Tf!ii on to 2.*? H (bj Dionnn of o boost.»jr ) Uv woi,;l'f. of th(- rliti.ro nb^noh at tho :-;t;jrt IB about ;>(.);r- iimnl-nv Ihnn hi n trioo in ;vlii«h thu I'nin.iet st.ri';o s^ji'lc ttn op(.irnt i on at l\v. upcoo of 1»^ M. i'hc nil;) l.vEjio (v^i.Lch w.-jf) cnrric'l out), i>roVed tJint tho mjn of ,'; rnni^eL nn^jno to [iroj'ol a raotooroBicql probn ir!?).v Jn.'id to n comsidoi'.'ible- decrosso in ri^ua of the entire; objffrt. '!'ho optircum nolution Ja to ncofflnrnto tlie probu t;o n nupiiroon] o jjpn<:ii b;; mean.1, of o rocVirst ongine nnd tJinn njcocutc furUu.T i;p< o«M..tif; up v;.ith tho holp of n tjiitij^-^ lo rnin^ot nnpino w-irVini; on yoljd fuel.

1?ibl .i of;!1?]j.-}i,y 1. T. Li twin, M. Wojcicki.: AΒ KxparJmuntal tstudj of Gombuotion of fjoiid Fuel for Ramjet. Arehiwum I'X'OCG- fjow ;5i)£).l.»u5n 5 /'V)7LV/ No. 4, pp. 447-459 ^. Li.J« '/-ucroiv: ^ircrrjft .-Jiid Misci.1.8 Propulsion, New York, John V; i 1 n.j nnd iSono, inc. 1958 - 357 - IAF-83-379

DEVELOPMENT OF INDONESIAN SOUNDING ROCKETS

Harljono Djojodlhardjo, Klenan Subandhi and Saulus Silltonga The Indonesian National Institute of Aeronautics and Space (LAPAN)

Abetract

The development of Indonesian Sounding rockets Iβ carried out by the Indonesian National Institute of Aeronautics and Space under its meteorological rocket project, which was commissioned in 1979. The development program has been based on objectives relevant to national development . Single and two stage sounding rockets have been developed, utilizing solid propellents. The single stage sounding rocket has a total length of 3036 an and a dinameter of 150 ran, with a total weight of 19.5 kg. The two stage sounding roeket has • total length of 4308 on, with 1906 an for the first and 2402 M for the second stage. Its total weight is 129.5 kg. Both types of rockets have been equipped with simple payloads consisting of tele- metry system, sun sensor and other instruments during test flights. - 358 -

IAF-83-381 "The Integrated Nozzle Assembly (TINA) Concept and its Impart Upon Coundina Rocket Economics" Stan Kent AstroSpace. Inc.

The first twenty five years of rocketry have seen numerous rockets developed that have in one form or another been modified to provide performance increases, rather than developing newer, laroer vehicles. One standard technique for inrreasina the thrust of a rocket has been the clustering of many smaller rockets around a central basic rocket. Perhaps the most common example of this technique ia in the McDonnell Douglas Delta launch vehicle and its of ° Thiokul-manufactured Castor motors. From an ideal performance perspective, clustering in this traditional mode is more inefficient than the performance delivered by one larger stage of equal thrust. However, the practical considerations of the cost of developing a new stac.e usually outweigh the extra performance gained by the use of a larger, single stage. Once the clustered rockets have completed thoir thrusting, they are dropped off, and the vehicle continues on staging once or twice more. The advantages of clustering allow a new stage of larger thrust to be developed from a number of smaller, readily available, usually lower in cost rockets than the alternative of developing a larger rocket motor. Another attractive feature of clustering is the freedom from the expensive (and potentially disastrous) problems of combustion instability. Large-diameter solid rockets typically exhibit greater combustion instability than their smaller counterparts. In addition, clustering allows a larger base diameter for the first stage, which, if the clustering is an integral part of the stage structural mass, can lead to a larger diameter second stage. Larger diameter stages allow a larger diameter payload compartment which allow the launching of experiments free from the volume restrictions of a comparable tandem staged vehicle. These design concerns are particularly important in the small sounding rocket field where experimenters are often times forced to spend large sums of .money to miniaturize an experiment to fit it within the constraints of a 4 or fc inch diameter rocket.

A larger diameter stage also allows the sounding rocket designer to take advantage of the larger size to fly an upper stage with a larger exit area nozzle. A larger exit area nozzle allows the exhaust gas to be fully expanded to the lower ambient pressure of high altitudes, thereby gaining valuable additional seconds of specific irrpulse, Nozzle size and weight limits can often limit the amount of this gain to a point where taking advantage of the reduced ambient pressure of altitude rocket burning is sometimes not worth the extra effort. - 359 - Under Hz own research funds, AstroSpace has evolved a vehicle concept that combines the traditional benefits of dusterinp with an innovative rocket nozzle to produce a 'jingle stage /chicle capable of greater performance and operational flexibility at a lower cost than that obtainable with currently available comparable multi-stage launch vehicles. The key technological innovation which makes a small sounding racket based single stage vehicle more cost effective than its more traditional multi-stage competitors iz The Integrated Nozzle Assembly (TINA1* This nozzle design allows the exhausting of several small rockets through a common nozzle to produce greater performance than that obtainable from separately exhausting rockets.

As a rocket ascends through the atmosphere* its nozzle either has to chdnge its shape to match its exit pressure to the ambient pressure, or it must operate at non-optimum conditions throughout moct of its flight. The majority of rocket vehicles are designed to do the latter because of the weight and complexity penalty that variable geometry nozzles entail usually more than offsets the performance gain from having the nozzle always operate at optimum conditions. Geometrically* an optimal nozzle would grow in exit area or shrink in throat area as the vehicle ascends to provide a larger expansion ratio for a given rocket throat size. A larger expansion ratio gives the exhaust gases an opportunity to expand to the lower pressure of the higher altitudes without undergoing wasteful shock discontinuities. TINA utilizes one large nozzle to produce a large expansion ratio for the engine that will fire at high altitude as the same nozzle for the motors that fire at low altitude. The low altitude motors are geometrically placed toward the exit of the nozzle to produce a lower expansion ratio consistent with the higher ambient pressure of low altitude exhausting through scarfed sub-nozzles into the main nozzle.

Thus, in one nozzle assembly that is an integral part of the vehicle structure, TINA provides all of the performance increase of a variable geometry nozzle without any of the complexity and weight penalties of major moving parts. A TINA-based vehicle, even though it incurs a performance penalty by not dropping off its spent motors, more than compensates for this penalty by the increased altitude performance of its second rocket firing in combination with a more efficient integrated structure. In addition, a TINA-based vehicle affords the user increased flexibility in accomodating larger payloads that can have a significant impact upon payload development costs. - 360 -

IAF 83 -384 AN ENGINEERING EVALUATION OF THE SPACE SHUTTLE OMS ENGINE AFTER 5 ORBITAL FLIGHTS

Dan David Director, Engineering PRA-SA-RI-25 Feb. 1983 Aerojet Liquid Rocket Company Sacramento, California

Space Shuttle Columbia has successfully completed five orbital flights; four of these being test flights, and the fifth the first opera- tional flight which deployed 2 commercial payloads. These flights have demonstrated that the Space Shuttle is indeed a reuseable vehicle. The success of the Space Shuttle is, of course, due to the successful perfor- mance of its many components and subassemblies. Two of these being the Orbit Maneuvering Subsystem (OMS) Engines. The payoff of a well planned development program has been realized, and will continue for another 95 Columbia flights with these first two OMS Engines. The payoff associated with using the OMS Engine design will go beyond Space Shuttle, as evidenced by great interest in a reliable multiple start reuseable engine for the Orbit Transfer Vehicle (OTV). The reuseable feature provides us with our first opportunity to observe the condition' of the engines after a flight and to trouble shoot reported flight anomalies. As in prior flights, one need not attempt to determine cause of a reported problem based on limited flight telemetry data. We can trouble shoot the system, verify the problem, determine the cause, and make repairs or improvement modifications to assure continued flight success. This paper provides an Engineering evaluation of the operational performance for the two OMS Engines installed on Columbia during the first five flights. The over 20 firings and 1800 seconds accumulated on each engine provides a good data base for this evaluation. The results of post flight inspections/checks are provided and maintenance activi- ties, which have been minor, are described. The exceptional performance of these engines is in part due to the simplicity of operation and redun- dancy built into the design. A brief description of these features is presented and highlighted where associated with maintenance activity. Also presented are the results of a detailed inspection and functional test of the engines at the Aerojet facilities prior to reinstaliation on Space Shuttle Columbia for continued flights. - 361 -

IAF-83-385

LE-5 Cryogenic Rocket Engine Development

H. Katsuta.E. Sogame,T. Fujita.K. Yanagawa National Space Development Agency of Japan H.Mlyajima National Aerospace Laboratory H. Inagawa Mitsubishi Heavy Industries Co., Ltd.

The National Space Development Agency of Japan (NASDA) has been progressing with the development of the H-I launch vehicle. The H-I vehicle is a three staged rocket capable of placing a payload of 550 Kg Into the geosynchronous orbit. The second stage of the H-I will be powered by a liquid oxygen/liquid hydrogen engine, named "LE-5". The development of the LE-5 is being conducted in three phases; design feasibility, design verification and qualification. Now the second phase is under going, and about half of all development tests have been carried out. The LE-5 is rated at 10.5 ton thrust and has the nominal 2 specific impulse of 445 sec at 5.5 mixture ratio and 36.8 Kg/cm a combustion chamber pressure. And good prospects have been got. This paper presents the development status of the LE-5. Simulated altitude tests were conducted using a newly constructed HATS (High Altitude Test Stand) at Kakuda Propulsion Development Center from October, 1982 to February, 1983. Thirty-five firing tests, including 3 full duration tests and 8 restart tests, were carried out and an accumulated duration reached 2712 sec by using 2 sets of the LE-5 engine. Main results are as follows. 1. The normal specific impulse of the LE-5 proved by these tests was 447 sec. 2. The normal operation in the required operational range and the restartable function were confirmed. 3. Many data about transient characteristics in the simulated conditions were obtained. Refering to these data, the design of LE-5 flightweigh engine was reviewed at the 1st critical design review (CDR) in March, 1983. - 362 -

IAF 83 387 ARJANF 3 THIRD STAGE PROPULSION SYSTEMS AND HH7 B ENGINE DEVELOPMENT. A. SOUCHIER E. KIRNER SEP MSB On the Ariane 3 version of the Ariane launcher, the third stage perfor- mances have been Improved by Increasing the loaded propellents from 8 to 10,7 tons and by Increasing the engine thrust an specific Impulse. Together with the first and second stage Improvments, these modifica- tions have boosted from 1 750 kg to 2 585 kg the satellite mass In geos tationnary transfert orbit for the ARIane 3 version. The program was decided In 1980. First flight Is scheduled for March 1984. To Increase the loaded propellent mass In the third stage, the L H2 tan*: has been lenghtened by 1 014 mm and the LOX tank by 218 mm. The new stage 1s designated H 10. The engine performances Increase has been obtained by changing from 30 to 35,5 10 Pa the chamber pressure and by chamber modifications. The new engine 1s designated HM7 EL It Includes all the modifications developed after the L5 launch failure. The H 10 propulsion systems i.e all the hydraulic and pneumatic systems of the stage Including the HM 7 B turbopump are designed, manufactured and tested by SEP (France). The HM7 B thrust chamber, consisting of the main injector, combustion chamber and vacuum nozzle extension 1s as well as theHM7AT.C. designed manufactured and tested at MBB. Major modifications In comparizon to the HM 7 A T.C. are : . A reduction of the throat diameter, resulting in combustion pressure Increase form 30 to 35,5 10 Pa ; . A redesign of the chamber cooling jacket in order to meet the H 10 stage requirements of a modified propel 1 ant mixture ratio and an Increased run duration ; . A 200 mm elongation of the nozzle extension which together with the throat reduction leads to an area ratio increase from 63 to 83. The HM7 A and the HM7 B T.C. design are compared and the final design data 1s summarized, in particular the cooling channel design for achie- ving an essential elevated creep rupture life 1s described. The tests were conducted from 1980 to 1983. The HM7 B T.C. was tested and qualified both In sea level and altitude tests. The results gained In these tests are presented and compared - 363 - with the teorical predicted values. One of the test main results Is the demonstration of the Increased spec. Impulse, which Is about 4 seconds higher than HM7 A. Three engines have been used for the test program at SEP Vernon. From the end of 1980 to April 1981, tests on the first engine totalized 1 751 s Including four runs with altitude simulation conditions. A se- cond engine with the final flight version of the MBB chamber was tested from April 1982 to March 1983. The third engine started Is tests 1n Au- tumn 1982 and will be Installed on the H 10 propulsion system which 1s to be fire tested between June and October 1983 on the PF 43 test stand of SEP Vernon. IAF-H3-3H8 .SMALL CRYOGENIC PROPULSION UNIT FOR UPPER STAGE APPLICATION

Akita Kayama, At sut.aru Watanabe, Yojj Shibato, T. (Jodai , Tpukuba Space Center National Space Development Agency of Japan 2-1 Senqen, Sakura-tnura, NiLhari-gun, Iharaki, Japan.

Utilizing the experience gained through the development of .Japan's first cryogenic propulsion system for the H-l launcher's second stage, the feasibility of cryogenic propulsion use foi third stage is being investigated. The third stage which currently uses a solid motor would be powered by a new small LO2/LH2 propulsion unit. This improved third stage is contemplated for possible on a future version of the NASDA launcher series. Inevitably the imposed requirements of performance and weight reduction become very stringent in order to compete with a solid motoi of high loading density and especially designed for third stage application. Three configurations of new propulsion systems have- been proposed. They are targeted to generate a 1 ton level of thrust for about 900 seconds. Basic features of these candidate configurations are given below. They all utilize a single LH2 tank and four spherical LO2 tanks with a cryogenic helium bottle submerged within the LH? tank. The helium will be gasified for tank pressurization through a heat exchager mounted on the thrust chamber. Configuration (A) is a pressure-fed design emphasizing the simplicity of construction and lower production cost. The combustion chamber is regenerative-cooled with hydrogen. The hydrogen flows forward from the aft section of the chamber and directly enters the injector. A radiation-cooled nozzle extension fabricated of a columbium alloy is attached to the aft of the regenerative-cooled thrust chamber. The LO2 and LH2 propellent tanks are pressurized with helium. The guiding design parameters are; Isp., 441 sec; Chamber Pressure, 7 kg/cm2a; Mixture Ratio, 5.5; Nozzle Area Ratio, 100:1; - 265 -

2 2 L02 Tank Pressure, 12 kg/cm a,- LHZ Tank Pressure, 12 kg/cm a. Configuration (B) is a puinp-fed design aiming at higher perform- ance and reduction in overall system weight. An expander cycle is chosen in which the pump-fed hydrogen flow serves as the thrust chamber regenerative coolant and then as the turbine working fluid before entering the injector. The two stage reaction turbine directly drives a two stage LH2 pump and a single stage LO2 pump, each mounted on a common shaft. A columbium alloy nozzle extension is attached to the thrust chamber and is cooled by radiation. The LH2 tank is pressurized with helium and the LH2 tank with hydrogen which is tapped from the turbine exhaust passage. The guiding design parameters are; Isp., 471 sec.j Chamber Pressure, 38 kg/cm2a; Mixture Ratio, 5.5; Nozzle Area Ratio, 300:1; Turbopump Speed, 90,000 rpm. Configuration (C) is also a pump-fed design. However, this system adopts an expander-bleed cycle in which approximately one half of the pump-fed hydrogen flow enters the thrust chamber cooling jacket, the remainder flowing directly to the injector. About 50 percent of gaseous hydrogen flow from the cooling jacket is utilised for turbo- pump drive and thereafter for nozzle dump cooling. The remainder goes to the injector. The high pressure ratio available favors the choice of a two stage pressure-compounded impulse turbine for driving the LO2 and LH2 pumps both of which are of a single stage centrifugal type and are mounted on a common shaft. Twin thrust chambers are provided to shorten the total system length and to achieve a higher expansion ratio within a given space constraint. The LO2 tank is pressurized with helium, the LH2 tank with the gaseous hydrogen bled from the regenerative cooling jacket outlet. The guiding design parameters are; Isp., 470 sec.; Chamber Pressure, 42 kg/cm2a; Mixture Ratio, 5; Nozzle Area Ratio, 400:1/ Turbopump Speed, 80,000 rpm. This paper discusses the detailed configurations of the three candidate LOZ/LH2 propulsion units, their performance, operating requirements, and the results of extensive engine testing to date. - 366 -

IAF-83-389

sr CHAMBER HEALTH MONITORINf. FOR RIllSABU ROf.KFT FNG1NES

Kkhrird J. LaBotz Aerojet Ltciiiici Rocket Company P. O. Box 13222 Sacramento, CA 95813 (iSA

Abstract

With the (iriivnl of reusable space propulsion systems, the new fii>ld of propulsion system health monitoring consists of measuring .md rrvW-wiiKj engine operating parameters which will warn' of ermine Hrierior.ttion or abnormal operation well in artvatire of any failure. The hf-alth monitoring data can be used to establish that rin efi'iitH" should be repaired or replaced, thereby avoiding a future flifjMt failure. This paper presents a status report on the development of a health monitorinq system for recjeneratively cooled thrir.t th.tinbers. The system employs a single measurement with a simple nonintrusive sensor to monitor the operation of the engine. Tho hasif measuring and sensor concept is explained and the results of borh laboratory and engine firing tests with the health monitoring system are presented. - 367 -

lAF-83-rwo FLYING RAILWAY - A MEAN FOR ORBITAL TRANSFER

T. Iwata

National Space Development Agency of Japan 2-4-1 Hamamatsu-cho, Minato-ku, Tokyo 105

ABSTRACT

The mechanical repulsion between the two coupled spacecraft when they separate in orbit can be a source of propulsion. The orbits should be shaped appropriately so that the separated spacecraft could meet another one at an appropriate point in space, while the spacecraft change their shape in a cycle between two modes, namely, conjunct mode and released mode. The linear accelerator might be the most efficient propulsion in this case to separate the two conjunct spacecraft. The rails or cables of the linear accelerator could be used also as a mechanism for capture and deceleration of the two spacecraft when they meet together. The concept of the spacecraft system, or the flying railway to be named, is presented and the critical areas of technologies to support the feasibility of this concept are studied. The concept of the flying railway is merely an aggregation of the conventional technologies, e.g., linear motor, rendez-vous & docking, attitude and orbital control etc. The scareceness of the uncertainty in the world of astronautics allows the cyclic sequence of the inertial motion to repeat itself almost perpetually. The advantage of the momentum conservation saves the propel- lant and the propulsion hardware to be lifted from the earth. The disadvantage of this system is the long voyage time unless the long stay in the microgravity environment is effectively utilized. Applications and the cost-effectiveness estimation for this concept are also investigated. - 368 -

IAF - 83/391

Status and Future Application of the RF-lon Propulsion System RITA including Interplanetary Missions

H. BASSNER? H.W. LOEB**

Radiofrequency Ion Thrusters (RIT) are under development in Germany since 1960. The RIT-Asseinbly RITA using the 10 cm thruster RIT 10 has been de- veloped and ground qualified for orbit control of geostationary satellites. With a thrust level of 10 mN and a specific impulse of 31 000 Ns/kg a mass saving of 10 % of the satellite mass is possible for a satellite of 1 500 kg and a mission time of 7 years. The first test of tne RITA-system in space is currently planned on the European Retrievable Carrier EURECA which shall be launched and retrieved By the Space Shuttle in 1987. On this spacecraft, which is mainly designed for experiments in the microgravity environment, the RITA will be flown as an experiment to demonstrate its operation in space for about 2 000 hours. Further application to commercial satellites can be expected in the near future. The RIT 35 thruster (discharge chamber diameter 35 cm, thrust level up to 200 mN), which is now on a laboratory status is considered to be a very useful tool for interplanetary missions like flyby and rendezvous of spacecraft with comets and asteroids. According to current scientific planning multiple flyby- and rendezvous missions are planned between the years 1990 and 2000 with the requirement of an excess velocity of 5 to 10 km/s which only can be performed by the use of electric propulsion. This shows clearly the necessity of the development of an electric pro- pulsion module. Such a system using the RIT 35 thruster can be available in 1990 if the development is started now.

* MBB/ERNO Space Division Ottobrunn/FRG **Physikalisches Institut der Universitat GieBen, GieBen/FRG - 369 -

IAF-83-J92 MPD Arcjet System Performance Test

K. Kurlki and ¥. Shimizu Institute of Space and Astonautical Science Komaba, Meguro-ku, Tokyo 153, Japan

S. Morimoto, K. Kuwabara, T. Kisaragi, S. Enya and Y. Sasao Ishikawajima-Harima Heavy Industries Co., Ltd. Shinnakahara-eho, Isogo-ku, Yokohama 235, Japan

Abstract

In Japan, a 20 W quasisteady magnetoplasmadynamic (MPD) arcjet was successfully operated onboard MST4 satellite and a 200 W unit is integrated in the first Spacelab for SEPAC experiment. Recently a new MPD arcjet system is being developed by ISAS to fulfill a prospective scientific mission which requires life expectancy of about 100 days in the case of continuous operation. Within the MPD arcjet system, the major subsystems are MPD head, propelIant storage and distribution, capacitor bank, charger, and solar array. An engineering model of MPD arcjet system with particular emphasis on the MPD head and the capaci- tor bank of about 2 KJ was developed and tested to demonstrate the technological readiness for flight irodel design. The MPD thruster was a quasisteady type and repetitively operated more than 105 shots. Thermal data were obtained which define thermal Interface between the spacecraft and the MPD arcjet system.

The cross sectional view of the new MPD head is shown in Pig. 1. The propelIant is injected into MPD head through cathode root and anode root. Molecular gases such as H2» CO2» CH4 and NH3 are used as propelIants. In the preliminary experiment, fundamental thruster characteristics of MPD head with NH3 propellent were obtained: 20 mN/kV specific thrust, 2,000 sec specific impulse and 20 percent thrust efficiency.

The endurance test of the MPD arcjet including the MPD head and three Fast Acting Valves (FAVe) was conducted at a back-ground pressure of 1 x 10""** torr before firing and 2 x 10~* torr after the firing for 600 gsee with H2 propelIant. Other components such as capacitor banks, a charger and a controller were arranged outside of the vacuum tank. - 370 -

The deterini net ion of MPI) electrode Losses is a very important item to define »-he thermal interface of MPD arcjet system. These losses were determined by one-dimensional heat conduction in metal cyclindnrs extended out of electrodes. The cathode temperature was found to reach an equilibrium temperature when the cumulative number of firings exceeded 2,000 shots. All of equilibrium temperatures a< each points wer« measured. Electrode losses were calculated by substituting experimental data into the one-dimensional model. At low repetition frequency total electrode loss was about 30 percent of the input power. As repetition frequency increases, a slight reduction was found In electrode heat conduction due to the radiative coolinq at electrode surfaces.

As three FAVs were insulated thermally from the MPD head, thei? surface temperature did not exceed 80°C at the high repetition frequency. Therefore all of FAVs were operated satisfactorily within operational temperature range during the endurance test of 10' shot*?. Prior to the system test the FAV component had already cleared endurance test for 10° shot?.

FAST ACTING VALVE

Fig. 1 Schematic of MPD arcjet - 371 - IAF-83-393

Power Supply Unit for Magneto Plasma Dynamic Propulsion Y.Shimizu and K.Kuriki Institute of Space and Astronautical Sience

T.Yoshida, T.Okamura, H.Harada and H.Obara Mitsubishi Electric Corporation, Ltd.

abstract Magneto Plasma Dynamic (MPD) propulsion has been developed at Institute of Space and Astronautical Sience. In 1981, 20W class MPD propulsion was carried by Tansei IV, 200W class MPD propulsion will be flight tested by SEPAC of Spacelab I on September in 1983. In future, .MPD propulsion is promising as a main thruster for interplanetary spacecraft and cargo orbit transfer vehicle. Verification test of 5 thru 25KW class MPD propulsion is considered using by Bus Flatform that is proposed in Space Station plan in 1990's.

Some problems of MPD propulsion are stability, reliability and power dissipation. MPD propulsion is made up of head that is electrode for discharge, propellant supply unit and power supply unit. Power supply unit is made up of Pulse Forming Network (PFN) capacitor bank, Fast Actinp, Valve (FAV) drive capacitor bank, Trigger (TRG) drive capacitor bank, charger for capacitor bank and controler. Conventional aluminum electrolytic capacitor has defects of short life, poor temperature characteristics and even liability to explosion. Film capacitor is free from these defects. But, in order to apply to MPD propulsion, its stability, reliability and thermal characteristics have to be verified. And the weight of the present film capacitor must be reduced.

This time, we manufactured ths capacitor banks of film capacitor, integrated them to the MPD propulsion system and put it to the endurance test.This paper describes the test results and some items to be investigated in the future, emphasizing on the capacitor bank. Specifications of film capacitor for capacitor bank are electrostatic capacity of lOuF, rated voltage of 250V and dielectic Loss tangent of 1.0% maximum. Most of film capacitors were subjected to selection test at parts level. Constant current sorce was selected for capacitor bank as power supply. - 372 -

12.5 xlO shots at O.bttz and 2.5 x 10 shots ai IJIz were performed. As a result of the test, the capacitors having undergone the selection test proved to be usable. The characteristics of sample capacitors connected to Hie FFH capacitor bank were monitored at regular Intervals. This showed that the change in electric charact.eri s ti cs hardly occured after 10^ shots. Endurance test results showed that film capacitor was superior to aluminum electrolytic capacitor in life and failure mude.

But conventional film capacitor's mass per stored energy was 8 times as heavy as aluminum electrolytic capacitor. In new type film capacitor was developed that mass per stored energy was 5 times. In future film capacitor take aim a* } thru 4 times as aluminum electrolytic capacitor. - 373 -

TAF - 83 - 39^

DESIGN OOBSlUEHATIOIfS FOR AW AMATEUR SOLAR SAIL SPACECRAFT.

Trevor Williams* and Patrick r.c

•School of Electronic F.nginpering & Computer Science, Kingston Polytechnic, Penrhyn Road, Kingston-Upon-Thames, KT1 SEE, England.

•'Tinperia] College of Science ft Technology, Department of Management Science, Exhibition Road, London SM7 ?BX, England.

Introduction

This paper describes work that has been performed as part of a project to produce a Phase A design study for an earth-orbiting solar sail spacecraft which could realistically be produced by an amateur group. The underlying approach has beeri to reduce the complexity of construction and operation to the minimum. This has led to a number of interesting design features which are described in the paper.

Orbital Strategy

In order to clarify the reasons for certain aspects of the proposed design, a number of misconceptions concerning the use of solar propulsion in earth orbit are discussed. For example, it Is in fact possible to continue to raise the orbit of an earth-orbiting solar sail while it is travelling towards the sun. This permits the use of a control strategy (for certain classes of orbit) that produces the maximum possible resolved force along the orbital velocity vector at every point in the orbit. The function describing the required spacecraft atti tude has been approximated in terms of Chebyshev polynomial s as a cubic function of the angle between the spacecraft velocity vector and the spacecraft-sun direction. For near-circular orbits a very simple attitude control strategy, involving an almost constant rate of yaw of 180^ per orbit, 13 a reasonable approximation to this function. It is a logical extension of this strategy to avoid performing a "flipover" of the spacecraft once during each orbit, as proposed by some authors. (This occupies several hours per orbit during which time the spacecraft is being decelerated by the solar pressure, and places complex demands on the spacecraft actuators and control subsystems). A major design - 37* -

if I his stratepy l^ that I hn gall must b*1 I w>- rt1 t.hr.t 1 r-, the two fa"«»3 of t h" sail arp 11 luminal «*d allofriat.p prlit K>! - and allowance must therefor*1 !>•» ip-"'"3 thH in nil sirpe'M ft of the spacecraft Spacecraft Configuration

ovm«*nt, of -i rolar sail Is a hlpihly er!f 1ml operation, and ill solutions proporcl to date hav<9 drawbacks - inlar .'.nil nludv <*roup.«i at. bo^. MARA .IPt. and F^A SPIO^VP'I ih« novl f •-»-^JT*'•" r?onrfp!irat. f"ii liprau.tP of fchfi "ompl >=xl 1 w f>f of otiier 'fersipns. Th>=» concept obnnon nr t'n= m.<">r?l In a v-irfanf. of th>= "wrap rib" design fotirept that bars w>1 for ripaceornft antennaa, In which radial r'b-T a»-p round a opntral bus, Tn thtfi design the motive foro" for of the Jia11 ts provided by stra.1n-enr>rp;y In Hip T-IITS, bpfnc provided by nordp. running between ?par t,lpg frrm sJ viv damped pulley.*?. The use of menhaninms - nn^b g^ r>fi(iy_r»uTent dampers - In wVdoh the restraining forp° l^ proportional to oord-deploynent speeri 1 eada to a robust noenario In which the system reanber a spned, nehievinp; a reasonable deployment Mm" of* a Cai nul aHonn :ire Riven fo1' the derivation of the hn.-.m -n den'med to optimise resistance to buckling during d«>pi ovtnent. Thp only active step required for deployment 1." detonation of explontve bolts retaining a oirrsumferGntft*\ clamp

T1 lust ra.t1pnn arc ptfven of the ma.^or features of the conf 1(rnrit !on provisionally adopted for the spacecraft: a rqnare 3al1 ?S m»t««»n on a side, with lenticular OFRP spars attached truant tally to a central, circular bus approximately L1^ mett-es 1n diameter. The sail material 1s Kapton metal Used on both aldpfl. Yaw and pitch control for making orbit adjustments are to be provided by phifttnR the spacecraft cent re-of-mass by alte^lnf? the position of a ballast mass. Poll control will be limited to cancel!inp: any residual roll after deployment, and disturbances from nail Irregularities. The Implications of the two-sided spacecraft d*>s1 vjr\ for various elements of the payload are discussed.

Conclusion

Although there 1.rs much further destftn work to be done, the concept presented here appears to provide the basis for a and robust spacecraft design that would be suitable ponstrtK»tton and operation by an amateur ^roup. If the process progresses satisfactorily through the Phase A stage, the attempt may subsequently be made to build a flight model - tb\ obtaining a launch, can be solved. - 375 -

IrtF-83-397

A CONCEPT OF LOW-THRUST RELATIUISTIC- JET-SPEED HIGH-EFFICIEHCV MATTER-ANTI MATTER ANNIHILATION PROPULSION SVSTEM Giovanni Uulpetti Telesrazio SPA per le Comunicazioni Sraziatl Uia Alberto Ber9amini 50 00159 ROME Italy

There is an increasing interest in Europe and USA about the very attractive performances that a space propulsion system based on the matter-antimatter annihilation process would exhibit* Although only a -feu years o-f preliminary studies about a so complex -field, concepts o-f engine design are evolving. The most suitable annihilation reaction -for poten_ tial space applications appears to be the antif»roton-nucleon annihilation at rest. Concepts o-f low-thrust and high-thrust engines have been proposed by JPL and US company inve*ti9e_ tors* In such models the possible utilization o-f the great amount o-f annihilation energy in -form o-f gamma ravs is not explicitly considered* In this paper we present a concept o-f antimatter propulsion system where a significant -fraction, of the gamma energy may be exploited for thrusting by using well-known processes of Particle Physics. The basic process here considered i* the electromagnetic shower induced by gammas the mean energy of which is about 200 MeU* The key point is to transform a fra__ ction of the photon energy into relativi*tic electron-posi_ tron pairs. Such particles are to be ejected together with the pions produced in the antiproton-nucleon annihilation* A cloud of ordinary matter where annihilations and gamma energy re-conversion take place is "deepened" in the field of the magnetic nozzle* Such nozzle would exploit the mirror effect well-known in Fusion Plasma Physics* Uβ have dealt with a limited number of problems of such a configuration* stressing the conversion process and the role of the K- mesonS' Both aspects had not considered in previous concepts* - 376 -

HIFUIKN'IS OP HoW'riARTES AND ELSOTRTOJU- CURRENTS V) ILASW r'BT R&EAHSToN TWTO VACUUM

A,V. fJure/i^h, A ,1 , MefTnrhfrM n, N.T. jfaahnhenk*

In appl i nafcf nn to Isqcr tluueter the probleni of «lr1t'f plaerpi outflow were oon3i'l°re

IAF-83-J99 OPTICAL PLASMATRON AND THHUSTUHS Yu.P. Raizer, USSR Different projects of laser propulaion ayatems are widely discussed, optical plaematron la a main part of laser driven thrustere* In theplaamatron hydrogen flows through optical diachargemmaintained by C02 - laser ra- diation, is heated up tm high temperature Hnd then ia exhausted expanding in the nozzle* The calculations were made for discharge deflagration in parallel light beam. But discharge ia nat stable, it can arbitrary move. To stabilize the discharge it ia neceaaary to fecua the beam and in this case the problem becomes much more complicate In the paper presented the problem of optical discharge deflagration in a gas flaw ia considered when the beam focusing is taken into account and gas discharge is sta- bilized being "attached" ta focus regian, One-dimensional linearized problem, ie formulate for which we can obtain analytical solutions. Discharge location, light intensity and its efficiency are calculated numerically for diffe- rent gas flow velocities.

M . ^ - 578 -

1AF - 83 - 400

CONSIDERATIONS ON TECHNOLOGIES AND MISSIONS FOR NON-CHEMICAL PROPULSION

Jerome B. Molltor Hughes Research Laboratories

The era of space exploitation la fully' underway and Missions which utilise spacecraft with increasing capablliles, extended lifetimes, and more deaanding propulsion requirements are being proposed to fully exploit the space resource. Such missions Imply great increases in the benefits and impacts of space propulsion and power subsystems with improved performance.

Electric propulsion is, by virtue of its high specific impulse and other characteristics, a concept which can provide great benefits for many space missions. Active electric propulsion programs are in place in many countries and numerous space tests of various systems concepts have been reported in literature from Japan, the USA, and the USSR. The rapid maturation of electric propulsion is further indicated by the recent operational use of augmented hydrazine reslstojets, for statlonkeeping, on Intelsat V and SATCOM geosychronous spacecraft and micropound pulsed plasma thrusters on the NOVA satellite to maintain extremely precise orbit control.

It Is a purpose of this paper to provide information on the characteristics and status of several electric propulsion concepts, and related power system technologies, presently under Investigation In the USA. Several electric propulsion approaches concepts are being developed and they may be broadly categorised as electrostatic, electrothermal, or electromagnetic, dependent on the physical processes Involved In the addition of energy to and acceleration of propellent. Specific thruster systems reviewed will include those using ion thrusters, reslstojets, arc jets, pulsed plasma thruaters, magnetoplasmadynamlc (NPD) devices, and several advanced concepts at earlier stages of development. In addition, some recant advances in power technologles which arc relevant to electric propulsion systems will also be briefly reviewed. - 379 -

The use of electric propulsion will alao be analyzed for several example missions in order to provide quantification of the benefits and impacts provided by its use. Earth-orbital missions euch as high precision north-south and east-west geosynchronous satellite stattonkeeping, station change, and low-Earth orbit control will be described along with a review of planetary nissions and a brief discussion of other potential benefits of electric propulsion such aa satellite charge control and reduced contamination. - 380 -

IAF-83-403 TECHNICAL ISSUES IN DYNAMICS AND CONTROL OF LARGE SPACE STRUCTURES By Michael F. Card* and Willard W. Anderson** NASA Langley Research Center Hampton, VA, USA

Requirement for three representative large space systems (Land Mobile Satellite System, Large Deployable Reflector and Large Space Platforms) will be discussed from the standpoint of dynamics and control. Pro- gress 1n ground testing of representative large antenna and platform sections will be reviewed including tests of a 25-meter antenna mesh section, a large wrapped-rib antenna section and a film of simulated astronaut construction of a large truss structure using a mobile work station concept. Packaging efficiency and achievable construction accuracy will be compared for several structural concepts. For some applications, the use of closed structural configurations or stiffer structures can eliminate serious dynamics and controls problems. How- ever, for large or precision systems, limitations in the accuracy of construction will be shown to result in requirements for active control to meet stringent requirements. Thus, many new and unprecedented prob- lems are emerging at the Interface of the disciplines of dynamics and control. The dynamic response of typical large structures to environmental dis- turbances as well as orbital transfer loads will be discussed. It will be shown that major dynamic loads are mainly self-generated. Recent studies of orbital transfer will be presented showing that large struc- tures assembled in low earth orbit can withstand practical propulsion loads for transfer to high earth orbits. Unique problems in the dy- namic qualification of large structures will be discussed/ Examples of limitations of ground testing will be presented illustrating the need for scaled or subelement testing approaches for large structures. Possible use of on-orbit dynamic testing 1s suggested; progress in the use of time domain techniques to determine structural dynamic charac- teristics will be reviewed to show that such testing could be feasible. Precision requirements for large space structures are Hkely to result 1n structures with tight joints but low damping. Simple studies of the Introduction of active or passive damping in flexible bodies will be presented. Results show that flexible bodies can have practical limitations In achievable damping. Studies of actuator mass charac- teristics Indicate the need for research Into the physics of actuator/ structure Interaction. *Ch1ef, Structures and Dynamics Division **Ch1ef, Flight Dynamics and Control Division For large flexible spacecraft the major challenge In controls Is the development of distributed control concepts. Related advances 1n modern control theory will be discussed. Results of theoretical studies to understand information transfer 1n systems with distributed logic elements will be presented. Analysis of the relative importance of global versus local feedback In continuous structures with dis- tributed actuators and sensors will also be shown. The area of param- eter Identification using distributed systems will be reviewed. Ex- perimental results will be presented showing application of lattice filtering (a technology spin off from speech synthesis research) to real-time Identification of dynamic parameters for a free-free beam. Applications of error modeling techniques for control of a spacecraft which has an articulated platform will be summarized. Progress will be demonstrated 1n development of strategies for actuator/sensor place- ment that account for the reliability of the control system components. - 382 -

IAF-83-404 Technology Requirements for Large Flexible Space Structures Ben K. Wada and Robert E. Freeland Jet Propulsion Laboratory Arthur A. Woods, Jr. Lockheed Missiles and Space Co., Inc.

The objective of this contributed paper, which is Intended for the Large Space Structure Session, 1s to Illuminate the authors' viewpoint re- garding the structures research necessary to develop confidence that large, lightweight flexible space structures will meet the on-orbit pointing and alignment precision requirements. Many of the ideas are formulated as a consequence of (a) defining mission requirements and developing a large flexible parabolic deployable antenna for classes of applications (b> determining the accuracy and value of the proof-of- concept structural hardware models, and (c) estimating the accuracy of the structural parameters which can be analytically and/or experimen- tally determined prior to the required flight to accommodate realistic projections of flight performance. The hardware development of a 55-meter deployable antenna has been undertaken to (a) demonstrate concept readiness for classes of appli- cations* (b) understand the problems associated with the fabrication, assembly, handling, structural testing and deployment of large flexible structures In a l"gH environment and (c) determine the accuracies to which the structural parameters can be determined prior to flight. The paper Incorporates the insight gained during the hardware development, the concerns regarding the ability to evaluate the necessary structural characteristics in a 1 "g" environment, and the potential value of an antenna space flight experiment. A review of the current state-of-the-art technologies for the analytical and experimental determination of large flexible structural parameters 1s based on experiences at JPL and various Industrial space applications. The state-of-the-art of these technologies will be extrapolated to assess the adequacy of evaluating large flexible space structural char- acteristics where the gravitational field 1s the major contributor to its behavior. Systems requirements for the knowledge of structural characteristics will be compared with information considered to be attainable from ground based test results and on-orbit evaluations. Total antenna system performance must consider the control/structure Interactions as they Influence pointing, attitude and shape control. - 383 -

Technology areas requiring further deveiopmer'c will be Identified. A preliminary conclusion 1s that current capability for predicting on-orbit structural characteristics using ground test techniques for large flex- ible structures 1s not adequate for characterizing the structure to the accuracy required to accommodate the system structures/control require- ments. Consequently, on-orbit system identification will probably be required to help characterize the structure for control of the structure prior to establishing an operat' al system. However, current technol- ogy readiness does not appear t be adequate for on-orbit system identi- fication to the accuracy necessary for the structures/control system. IAF 83-405 -/

"The Cyclosymnetric Approach for Solving the Dynamic Problem of Linear Modular Repetitive Structures" i

C. Arduini - Aerospace Department, University of Rome ,•,•£

ABSTRACT

The attempt of using the repetitivity characteristics of a structure for reducing the numerical effort required for the dynamic analysis has never been brought to its extreme possibilities, that conceptually are: a) the problem size should be reducible close to that of a single bay. - This sub-element contains actually all the information needed for d£ termining all the roots in all the frequency range. ! b) When analyzing the system in limited bands of frequency, the bay model should be furtherly reducible. This paper presents two techniques which approach the results above: : i) the "cyclosymmetric" procedure, which is basically the application of the V Discrete Fourier Transform to the modular structure. i This technique is already known for "ring type" boundary conditions. The paper shows how it is possible to extend the technique to other conditions. Special reference is made to the clamped edges, a form which can actually representjby a suitable transformation , any possible symmetric boundary condition (unsymnetric conditions can be dealt with as well). The eyeIα- f symmetric technique transforms the original problem in a special form which is spectrally resolved in terms of the "ring type" roots. The compu tation of these roots is therefore a prerequisite operation that can be performed however on problems of the bay size. ii) The "spectral condensation, a techniques which, given a prescribed accu ] racy, reduces the model size to what is actually needed for obtaining | that accuracy in each prescribed frequency field. Condensation is al- J ready known in the low frequency field (f.i, Guyan condensation). Here \ it is used for; J - 585 -

a) reducing the bay model before starting the cyclosymnetric procedure; b) reducing the size of the problem obtained by the cyclosynmetric "spectral transformation". The"spectral condensation" technique has however a wider potential than described here, and can even be used in connection with conventional dy- namic analysis procedures. By using the abovesaid methods it is possible to obtain computational sa- vings which can be noticeable for structures with many bays, many internal d.o.f.s and few interface d.o.f.s. Special care has been given to the obtainement of the eigenproblem in a standard "linear" form, which is the most suitable for numerically economic solution. The paper is based on studies already made and under performing under the ESA Contract N. 4348/80/NL/AK(SC) and 5620/82/NL/PB/SC. - 386 -

IAF-83-406

"Gravity Effects on the Dynamic); of Flexible-. Elongated Structures"

Ugo I'onzi

Sciioia di Ingegneria Aerospaziale dell'Universita di Rcma

ABSTRACT

Testing on groviid very flexible systems requires to select ap|.i opr i.it <• ly

the support conditions in order to ensure the structure integrity and to

affect its degrees of freedom with the minimum number of constraints. Siini

lar situations are experienced during the validation of control niatliemai i

cal models, when testing on simple shape structures, like beams and plates.

Hanging vertically flexible elongated structures from one end r.in ofI en

solve the problem when no different ways are allowed without damaging tin-

specimen or interfering with its motion, as in the case of multipoint sup

port. The circumstances which obligate to handle elongated structures by

vertical handling have been already encountered, on the other part, with

many types of booms (antennas, probes, etc.) which have a l.irgr-system-bp

haviour.

During the motion, the structure will be equally exposed to distributions

of gravity forces, which influence the response by quantities even remark.! ble, if an accurate analysis is requested.

This gravity interaction has to be taken into account in the mathemati cal model, and also elementary solutions can be promising for establishing

suitable criteria of evaluation and correction of the experimental results.

With this purpose, starting from the complete equation in terms of the eigenfunct ion :

Similarity considerations are firstly used in order to re"fer the behaviour of the structure to limit beam-like or chain-like cases (classic models). - 387 -

Successively, approximate solutions of the eq. (1) arc obtained by per- turbing the eigenvalues and the eigenfunctions of the classic models accor ding to:

and expanding the corrective terms in scries of the basic cigRnfunrtions _ GΓ,

P> , eigenvalue , coefficient of the expansion

Numerical applications giving the frequency and the mode shape modifica- tion which characterize the approximated models are done and presented. The paper takes origin from the york under the ESA Contract A348/8O/NL/ AK(SC). - 588 -

Authorsi A.3. Gvamiohava IT. 7* Myshonkova A.0. Sokolor V*M. Spyrek

THESES OP THE REPORT "THE FEATURES Of THE SPACE STRUCTURES DYNAMIC

The greater part of the external loads having an effect upon apace structures during their transportation, unfolding and exploitation ia of dynamic character* Side by aide with the processes stipulated by these effects and well described by the methods of structural dynamics there are some processes which require the development of new design methods* One of such problem tasks ia the structure design for impact and vibrational overloads taking place in the transportation period* In automatically unfolding systems the reliability of unfolding is ensured by appropriate selection of the unfolding mechanisms* Methods of the kinematic and dynamic analysis of the space trusa structures unfolding bare been developed for investigation of the reliability and for determining optimal parameters of the unfolding mechanisms* A number of new problems appeared in the oourse of investigation of the structure behavieur in the period of its operation* Most of them are related to the acouraoy of guidanoe and stabilisation of large-scale flexible objects, and they are due to the effeot of elaatio deformations on the position of the electrical axis and the behaviour of the control system* for large-scale space structures the jaint design of the meehanioal struoture and the control system has certain engineering difficulties* The prooedure of pre-eeleetion of some control system parameters and the procedure of simplified representation ef the mechanical structure have been suggested for variant desinglng* - 389 -

IAF-83-412 On Some Spacecraft Fatigue Crack Propagation Problems J. Gedeon Technical University Budapest, Hungary The critical stress-intensity factor Kj._ as deter* mined on standard compact test specimens is not directly applicable to thin-gauge sheet structures* The effective critical range of stress-intensity factor -AK_ for such conditions can be calculated by curve fitting to the re- sults of the respective fatigue crack propagation tests. A new, more exact coordinate transformation sethod has been developed for this purpose. It is based on the For- man formula

dlf F (i - R)KC - AK and it is giving the standard deviation of the relative fitting errors, too* For long-life spacecraft applications, the method can be extended to cover the determination of the tres- hold stress-intensity factor range Aui^ as well* The formula to be adopted for this purpose reads either AB? /r=n-l/ °F (1 - or

The correct one of them will be singled out on the basis of the ratios of the respective relative error standard deviations* For this purpose a statistically significant number of test data is to be accumulated. - 390 -

Corrosion respective atmospheric effects may have a decisive influence on the rate of crack propagation. The general character of corrosion-fatigue test diagrams can be interpreted as follows* For normal, corrosion-free tests, the middle section of the crack propagation curve follows the power law type Paris-Erdogan equation ft - °PAK" A statistical relation found by several authors bet— 'seen the constant Op and the exponent n of this equation can be interpreted in terms of the existence of a charac- teristic crack increment da* and of a characteristic stress-intensity factor range ART. NOW, the general cha- racter of corrosion-fatigue diagrams seems to indicate n growth in the value of da* and/or a decrease in AK*, both of them being factors in the Paris constant Cp. Some recent test data may indicate also that even pure atmospheric air can erert a corrosion-like influence on certain light alloys, combined with a significant lo- wering of the treshold value ^^J-J,* Should this prove to be true, then realistic long-life spacecraft fatigue tests will have to be run in a suitable vacuum-chamber. Later, a correction factor for the life extension to be expected under vacuum conditions may be substituted for this. Accumulation of a sufficient amount of service date will be the precondition to this. Wβ do not use an elevated load level crack initia- tion block in our test programs. The test laboratory ca- pacity seemingly lost by this is more than compensated b? obtaining also realistic data for the full life apan of the specimen to be investigated. - 391 -

IAF-O3-4I;* EXPERIMENTAL INVESTIGATION OP THE EFFECT OF THE STRESS- STATE MODE ON PLASTIC DEFORMATION OF STRUCTURAL MATERIALS AT LOW TEMPERATURES G.S. Pioarenko, A.A. L^bodev, B,I. KovalchuV IntercosmoB Council, USSR Academy of Sciences The analyaie is made ofraodern methods and equipment for materials testing at cryogenic tempera-ft urea* The au- thors describe an automated complex developed at the In- stitute for Problems of Strength of the Academy of Scien- ces of the UJcr.SSR. for low-temperature testa of structu- ral materials under conditions of the controlled biaxia] loading which imitates the operation of cryogenic vessels and pipe-lines. Analyzed are the results of experimental investiga- tions into the laws of elasto-plastic doformatlon which were made on the materials of different grades loaded in accordance with complex programs over a w.ido temperature range. Main attention is given to new effects which are asslciated with the Influence of cooling on the process of deformation under conditions of stress state variation. Variants are presented of analytical description of experimentally established laws within the framework of the elastic-plastic deformation theory and the plastic flow theory. Recommendations are given as to the choice of equivalent and allowable stresses in designing cryo- genic equipment components. - 392 -

IAP- U.i~\ 74 STUDY ('P TUB STRESS DISTRTWJTIUN HEAR CUTONTH IN THTTT-- STRICTURES

A»f1. 'luz, T.!J. Otifvr'j//9it)'"inli:o, K.T.

Tn' I'Tf1 o.'irnoq Council, llf-'SR Add^ny of S

The ii •"'•i-l t> f 'rnaurin;^ l.lie n!>0'?H3nr,v alronrll- of gtrufH r<: ':"!''i'"inl;a In various br-'i richer of toc-'inol o/'.v .- = 11«? in ).«• on.l'ir, rood {-in r<>'jut r?» -TMI I -'j for (.hnt.f ••"•• i r\> I r^rim*'\o>} )n nir'T'ift li'ja raised tit'.: proM.on of gtr4oi;irrel :'l'?al^Ti "f f.hin-WHji"i '-|r^c^u^1oβ aa one of t.hf nrwnt' probW'iia or mn'^hrinl.ca. Tho proa^nn^ of outon^a atif? fncluaione of cue forwH and attffnossen r>.r-mgr>rj non-uni.fonni f:y aivl d'fi- turb.mr.f.1 of a^rr'fis n.e'l.dfj u»id- r th;> a^1 ion of variunsj ?!.'• <:h'»n! rial mid tli'^rmal lotuls, nan a e1nn1fioant ofMf.i;t on 'ii^ 1 onii-o.fjΓ-T;,'! n.'f capaoll.y of at run huve. Thoory ia pf'opos'.1'1 and pt'oc^'liirna am wnr'-^d or. I fnv solut.lon of linear and nori-) l.inar probloms of sialics ^ f rjlK'll fit.run Lures woakoin."! by on'; or rr v>rail cutont.3 arvi fabrical.od from nod or n rri*?'-al.li

IAF-83-415 Modal Damping Estimates of MOS-1 Solar Array Paddle Yoshinori Fujimori National Space Development Agency of Japan Junichi Kato Tokyo-Shibaura Electric Corporation Susumu Toda National Aerospsce Laboratory

The modal damping coefficients of MOS-1 solar array paddle have been estimated based on the experimental results of the paddle substrate; a prime load carrying component of the paddle structure, and theoretical extrapolation. The damping coefficient values of 1st,2nd, 3rd and 4th modes are 0.69% (U.5Hz), 0.07%(49.7Hz), 0. 277,(61.2Hz) and 0.07%(96.7Hz) respectively. Also this substrate experiment reveals- that the effect of the air vanishes at the level of 0.01 Torr and that the relative alignment of fibers in CFRP skin versus the lines of principal stresses in the deformed state is strongly correlated with the damping level. Zener theory of thermo-elasticity coupling model has been applied to derive the damping coefficients of the plate. Then modal damping coefficients of MOS-1 solar array paddle whose resonances lie in the range 0.2 - 2 Hz are estimated by making use of the fitted curves to the experimental data. Next, the estimate is improved by considering the additional contribution from the solar cells and adhesive. Supplementing the foregoing estimate, quantitative assessment on the damping effect due to interface friction somewhere in the structure is made leading to the final estimate that the modal damping coefficients of MOS-1 solar array paddle would not be lower than 0.003. - 39* -

PAPER I.A.F. - 83 -416 TITLE: EFFECTS OF MOISTURE AND THERMAL AGEING ON STRUCTURAL STABILITY OF SANDWICH PANELS. AUTHORS: F.Morganti - Soc. Selenia Spazio -Roma- Italia M. Marchettl- Dip. Aerospaziale - Univ. Roma - Italia G. Reibaldi - E.S.A. - ESTEC •; Noordwijk - The NetherJands

ABSTRACT The operational frequencies of the reflectors are increasing and also the dimensional stability requirements. As a consequence, the in-orbit thermal distorsions shall be mi- nimised and the relevant parameters influencing the coefficient of thermal expansion (C.T.E.) shall be examined. Most of the reflector structures are made of sandwich panels with composite skins. This type of structure is very sensitive to the environmental conditions which can induce some change In their structural behaviour. Either moisture and thermal ageing are able to change the physi- cal relationship between the fibres and the matrix: the former, degrading the properties of the matrix itself, the latter, indu- cing micro-cracking inside the composite. Both these effects influence the coefficient of thermal expansion and there is a strong relationship between them. The moisture content is a fun- ction also of the thermal ageing and furthermore the moisture has an impact on the micro-cracking. In order to understand the influence of moisture and thermal age- ing on the coefficient of thermal expansion more clearly, both these parameters will be investigated separately by a test pro- gram. A mathematical model to predict the moisture/ absorption/desor- ption of sandwiches will be developed and compared with the test results. Comparison with existing data shall be presented. - 395 -

IAF-83-417 THERMO-MECHANICAL BEHAVIOUR OF CFRP TUBES FOR SPACE STRUCTURE'S 6. Reibaldi Mechanical Systems Division, ESTEC European Space Agency Carbon fibre reinforced plastic tubes with the increasing dimensions and performances requested for space structures are becoming a basic building element of boom type structures for big precision reflectors, payload support structures (like the Modular Payload Support Structure or Shuttle Pallet Satellite or the European Retrievable Carrier). It 1s very Important for such type of applications that the-CFRP tubes have minimum thermal distorsions and very high stiffness. An extensive test program was performed to characterise the CFRP tubes that are used for such applications. Measurements of coefficient of thermal expansions, thermal conductivity) thermal cycling, micro- structure behaviour, mechanical tests and outgassing tests were performed. Particular Importance was given to correlate the micro- cracking with the thermal cycling and the coefficient of thermal expansion. Most of the tests were conducted at ESTEC (European Space Research & Technology Centre, Holland} by the European Space Agency 1n the frame of the technology research activities.

hi - 596 -

TAF - 83 - 418 TESTS AND PREDICTION OF COMPOSITE MATERIAL VISCOELASTIC BEFIWIOR FOR LARGE SPACE STRIIOTJRKS BY Luigi BALIS CREUA, Renato BARBONI,Antonio CASTELLANI, Isidore PEBONT DIPARTIMENTO AlitOSPAZIALE Via Eudossiana 16 - 00184 ROMA - Italy

The inportance of the vi9coelasticity for large space structures in many service environments of composite materials is veil-known. The temperature-dependent mechanical behavior, causes thermal expansion, damping of dynamics response,creep... On these problems several investigations have been carried ou» foi composite materials at the Aerospace Department. Particular attention is paid in this paper to the vacuum and reversible temperature effects on which there is little experimental data in the literature, especially with anisotropy. A series of experimental tests are reported on two materials: carbon fiber and glass fiber for three lay up sequencies. Static and dynamic tests are carried out in vacuum chamber (10 Tort ) and terperatures until 100° C. The experiments in the dynamic field are performed by an electromaqiipK<- exciter of the first and second bending mode in the frequency range between 5 and 200 Hz* The measure of the damping ratio is worked by the frequency sweep neHnyi and decay transient. Analitical forms of thermal expansion coefficient and damping have been fitted to experimental data. For particular types of material symmetry explicit interrelationships are deduced in terms of engineering properties. Comparisons between theoretical prevision and experimental data complete the work. - 397 -

IAF-83-419 NON DESTRUCTIVE TESTING OF HONEYCOMB SPACE STRUCTURES BY COMPUTERIZED THERMOGRAPHIC SYSTEM R. MONTI - G. MANNARA Institute of Aerodynamics "U. Nobile", Univ. of Naples (ITALY} " '

Complex honeycomb Space structures (I.e'. antennas, solar panels etc) must be inspected and accurately tested before flights. Ultrasound systems are typically employed, but they are rather complex (they often use water jets to follow the specimen surface) and suffer from a number of drawbacks due to the time necessary to scan the entire surface, to the relatively poor resolution and to the difficulties of locating the defects depth. The thermography, which allows a thermal mapping of a surface, can be employed with success for the detection of the position of these defects and their evaluation in all the cases in which the defects (delaminations, non effettive bondings, cracks etc) cause a thermal resistance due to the low conductivity of the air filling the defect volume. The basic idea is to create in the specimen a heat flow distribution which is altered by the presence of the defect and to detect the resulting surface temperatu- re distribution. Each class of defects suggests different heat flow pat- terns and heating procedures; for instance radiative, convective or con- ductive heating (surface, line or point sources) may be employed and the thermographic observation can be performed at thermalized conditions or during the heating or the cooling of the specimen. The typical defects in structures made by metallic honeycomb and by carbon fiber plates consist in imperfect local bonding between the plates and the honeycomb; this class of defect 1s therefore considered 1n more details. The procedures which have been explored consist in a rapid heating of one face of the panel (by radiant sources or by hot air) and in the simultaneous thermal observation of the panel surface (either from the opposite or from the same side being heated). A numerical analysis has been carried out to derive the parameters neces- sary to identify the experimental procedure (heat flux, heating time, observation time) as function of the specimen characteristics(honeycomb material, plate material, panel thickness, honeycomb cell dimension and honeycomb wall thickness). It can be shownthat the local initial heating rate difference (between the bonded^and unbonded structure) depends on the non dimensional parame ter: Kp™ ^fcy^LS Ka,) whereIU, K^ are the thermal conductivity of the air and of the honeycomb material, L is the honeycomb height and s 1s the defect thickness. The different heat flux is detectable at - 398 -

the surface according to the p-late charecteristies. The thermal footprint pattern reveals the non bonded honeycomb areas; thp picture is more or less accurate according to the relative values of the in plane and the normal to the plane heat diffusitivies of the plate ma- terial . It can be shown that the best detection of the defect occurs when K,,i<. much larger than one. A computerized thermographic equipment has been extensively used for the detection and local evaluation of these defects (by zooming technique) and a software has been developed for avoiding the difficulties ronne

IAF-83-421

HIGH CAPACITY POWER SYSTEMS FOR SPACE

Jerome P. Mullin, Manager, Space Energy Systems Judith H. Ambrue, Program Manager, Chemical and Thermal Systems

Space Energy Conversion Office National Aeronautics and Space Administration

The advent of the operational space shuttle opens new horizons for future peaceful uses of space. The feasibility of many such missions will depend largely on the availability of large amounts of energy at an affordable cost. The energy demands of missions such as advanced outer planet orblters, direct broadcast satellites, and lunar and plaiietay bases will be three to four orders of magnitude above the energy available in present and near future missions. Our presently used space energy systems consisting of solar arays, nickel-cadmium batteries and, occasionally, radioisotope thermo-electric generators (RTGs) will not be able to meet demands of the future. Consequently, the major thrusts In todays'a research and technology efforts are directed towards high power, long-life and reduced cost.

Large photovoltaic arrays are expected to be the first choice in power generation. Major thrusts in research must Include improved efficiency at high flux, high specific power, and increased radiation resistance. Blanket and array technology includes thin blankets, high concentration ratio low-cost arrays, and gallium arsenide technology. New emphasis is placed on lightweight structures for near-earth application. Storage of energy in advanced space system is expected to be accomplished by the combination of fuel cells and electrolysis and by nickel-hydrogen batteries. Experiments are in progress to prove the feasibility of fuel cell/water electrolysis systems utilizing both the alkaline electrolyte systems and the acid or solid polymer electrolyte systems. Major emphasis is placed on long life, space qualified subsystem component technologies. Because of the primary importance of energy storage, a parallel effort to advance nickel-hydrogen battery technology is carried out. A bipolar design which would permit active cooling and be specially useful for high voltage power systems is being explored. - 400 -

To convert heat froa source* such a* solar collector*, nuclear reactora or isotopes research is focuased on advanced thermoelectric •aterials. Synthesis and critical property aeasureaents are in progress. Alloy* and compounds containing boron and carbon or boron and silicon are investigated aa well as rare earth sulfides* Theoretical studies that will lead to a predictive aethodology are In progress in addition to the phenoaenologlcal approach. Additional efforts in the a»*easaent of static and dynamic altenativea to theraoelectrics arc also in progress. Special effort* are underway to develop the capability to control the generation and distribution of aultlkilowatt power in space. This includes research on power electronic components, heat pipes, radiators, rotary jointa, tranaaission lines and control technology - aa well as preparation of guidelines on apace plasaa/high voltage interactions for spacecraft designer*.

The satisfaction of future needs 1* expected to proceed froa such research effort*. While there 1* no sure way to predict the particulars of application* not yet planned this work •eeks to Incorporate the basic idea* of coaponents that will be needed for the high power, long-life, high energy density power eubaysteas of the future. - 401 -

XXXIVTH CONGRESS OF THE INTERNATIONAL ASTRONAUTICAL FEDERATION BUDAPEST - HUNGARY, 9 - 15 OCTOBER, 1983

IAF-83-423 OPTIMISATION OF CONCENTRATING SOLAR CELL SYSTEMS WITH PASSIVE AND ACTIVE COOLING

ABSTRACT

JORGEN BLUMENBERG •)

#) DR.-ING., CHIEF ENGINEER, INSTITUTE C FOR THERMODYNAMICS TECHNICAL UNIVERSITY OF MUNICH FEDERAL REPUBLIC OF GERMANY - 402 -

For judging the quality of a power system for application in space the total efficiency is not a usable parameter like on earth but the specific mass of the system, which is the ratio of the mass of the power system and the net electric power in kg/KWe.

For Bolar mirror systems and nuclear power plants with turbo- electric generators the specific mass of the systems were described in the literature /1, 2, 3, 4/ and presented at the IAF-Congresses at Munich (1979), Tokio (1980), Rome (1981) and Paris (1982) as a function of the mission para- meters and the technological data of the system.

The following work analyses the specific mass of solar cell systems with concentrating mirrors. Basis of this analysis are gallium-arsenid-solar-cells as well as silicon-solar- cells being specially dotated for high solar concentration.

Following three types of systems are analysed:

A. Solar cell systems for concentrated solar radiation without active cooling for solar concentrations between C = 1 and C «= 1000, cell temperatures up to 350°C and a distance to the sun between 0,5 AU and 3,5 AU.

B. Solar cell systems for concentrated solar radiation with active cooling by means of a cooling cycle with radiator. Solar concentration , cell temperatures and distances to the sun are the same as in A.

C. Solar cell systems f.ot concentrated solar radiation with active cooling an a low-temperature turboelectric system which converts partly the waste heat of the cooling cycle into electric energy. Solar concentration, cell temperatures and distances to the sun are the same as in- A and B. - 403 -

For these three types of systems a thermodynamic-mathematical model is developed. The calculations are made on a computer. The results are evaluated and analysed.

Literature /1/ Blumenberg, J.: Optimisation of powerful energy supply systems for application in space, Acta Astronautica, Vol. 8, No. 8, pp. 839-854, paper presented on the XXXth IAF-Congress in Munich 1979 (2( Ruppe, H.O. and Blumenberg, J.s Optimisation of solar power plants with rotating electric generators, Acta Astronautica, Vol. 9, No. 5, pp. 317-328, paper presen- ted on the XXXIst IAF-Congress in Tokio 1980 /3/ Blumenberg, J. and Ruppe, H.O.: Comparison of nuclear and solar power plants with turboelectric generators for application in space, paper IAF-81-184 presented on the XXXIInd IAF-Congress in Rome 1981 /4/ Blumenberg, J. and Panagopoulos, P.: Net electric power of concentrating solar mirror systems for application in space as a function of the distance to the sun, paper IAF-82-401 presented on the XXXIIIrd IAF-Congress in Paris 1982 IAF-83-424 DESIGN OF AN ELECTRICAL POWER SYSTEM FOR EXTENDED-DURATION SPACE SHUTTLE MISSIONS I.M. CHEN AND R.E. ANDERSON ROCKWELL INTERNATIONAL CORPORATION SHUTTLE ORBITER DIVISION DOWNEY, CALIFORNIA, USA The Space Shuttle orbiter is a multipurpose spacecraft. In addition to its demonstrated capability as a reusable space transportation vehicle, the Shuttle orbiter is actually an on-orbit facility, a resup- pliable laboratory, and a manned work station in itself. To fully exploit these potentials, the Shuttle must have extended orbital-stay capability. To accomplish this objective, a multi-kW integrated elec- trical power system (IEPS) which can meet the projected Shuttle payload power and mission- duration requirements has been conceptually defined. The IEPS utilizes the existing fuel cells to provide power only during the orbiter launch and entry phases of the flight and during a contingency abort. For long-term storageability, hydrogen and ox- ygen fuel cell reactants are stored at ambient temperature and high pressure in fiberglass, filament- wound composite tanks. The on-orbit power is generated by a 47.6-kW, flat-fold, flexible-substrate, photovoltaic solar array with high efficiency silicon solar cells. The solar array is stowed in the or- biter cargo bay and deployed for the on-orbit operations. Three SO Ah nickel-hydrogen storage bat- teries are incorporated to furnish all the spacecraft and payload power during eclipse and are re- charged by the solar array during orbital sunlight. An autonomous voltage regulation and power management control system is devised to sequence the commands for the solar array deployment and stowage, to transfer the bus loads between the fuel cells and the solar array/battery power sub- systems, and to monitor and regulate the battery charge/discharge performance. A typical Space Shuttle mission scenario with the 1EPS is depicted below. The (EPS permits the orbiter to perform extended-duration missions constrained only by the refurbishment of cycle-life-limited components and/or resupply of other consumables. In this paper, the design and mission performance characteristics of the IEPS are presented. Techniques for solar array/battery high voltage dc regulation, power switching, and controls are discussed. The orbiter integration interface design considerations associated with deployment and stowage of the solar array in the orbiter cargo bay, thermal dissipation of the batteries and power regulation equipment through the orbiter space radiators, and mission safety and power system redundancy requirements are identified and evaluated.

j- 1HR •J

IAF-83-425 IDENTIFICATION OF POWER ANALYSIS MODELS FOR ETS-III OPERATION T.Ito*. F.Imai**, S.Kuwajima**, H.Nagano** * Toshiba Corporation ** National Space Development Agency of Japan ABSTRACT This paper describes the identification of power analysis models of BOP(the Bus equipment Operation analysis Program) for ETS-III operation. TheETS-III(Engineering Test Satellite III) was launched on September 3, 1982 and on-orbit operations have been made successfully since then. Simulations are performed with the BOP prior to the specific ETS-III operations to see 1f they can be performed safely in terms of electrcal power and thermal control situations. It is necessary to identify power analysis model first and improve the model for higher accuracy. The power analysis model incorporated 1n the BOP includes solar power gen- eration.power consumption,battery depth of discharge and shunt dissi- pator function. Studies for model identification have been performed by using flight data and simulation results. As a result of these studies,the power analysis model meets well with the actual spacecraft power situation and the aimed accuracy of the model is achieved.

Tab. 1 Summary of Model Identification

ITEM RESULT

Power Generation within + 10 watts Power Consumption within + 10 watts Battery OOD within + 5$ Tab. 2

Shunt Drive Voltage wjtb1n + 0.5 volts - 406 -

200

Flight Data a> *-•+ BOP Results

100 -

17:20 17:25 T1me(UT) F1g. 1 Power Pred1ct1on(YA#7,l08day '83)

Tab. 2 DOD Prediction

Flight Data Predicted Data MODE DCHG CHG DCHG CHG

==00* 12.4 14.2 12.6 12.7

=30° 12.6 14.0 12.9 13.2

=4=400* 10.1 11.5 11.4 10.8 ' '7

- 407 -

IAF-83-426

COOPERATION FOR MULTIDISCIPLINARY RESEARCH ACTIVITIES FOR SPS

Makoto NAGATOMO /* Institute of Space and Astronautical Science 4-6-1 Komaba Meguro-ku, Tokyo 153 JAPAN Solar Power Satellite (SPS) system is considered as a promising future energy system which will be compatible with the present electrical power system. The study on SPS, however, is not still on a very early stage. The issue to be discussed in this paper is cooperation of activities of broad research areas required for SPS project. There exist many government and academic research organi- ' • zations and private research groups which are dedicated to solve highly sophisticated problems concerning individual discipline. Some of them can handle complex systems requiring broad research fields, but the complexity of problems involving SPS is more than their capability. It is too early however to establish a dedicated organization for SPS. At the present, those existing research organizations should participate in SPS research > activities. The cooperative activities requiring effort ^ of individual disciplinary field are such as: 1) identification of task areas anticipated to involve in any phase of the project thru completion of the first operational model, 2) identification of problem area and approach to solution of unknown phenomena and 3) evaluation of candidate systems. It is essential that a core research group which may \ be small but well recognizing the importance of SPS and its influence on human life should lead the activities of those many big research groups toward SPS concerned research. One of the incentives to encourage multidisciplinary research activities is a international research project utilizing space station as a multipurpose test bench. This project team will work as a core group to promote f. cooperative multidisciplinary research activities. - 408 -

IAF-83-432 THE LIQUID DROPLET RADIATOR - COMPONENT AND SYSTEM ANALYSIS A.T. Mattick and A.P. Bruckner University of Washington Seattle, Washington, U.S.A. 98195 The liquid droplet radiator (LDR) is a heat rejection system for space which uses a cloud of heated submillimeter droplets in.place of the solid radiating surfaces of conventional radiators to radiate waste heat. The large surface to volume ratio of the droplets allows this radiator to be far lighter than solid surface radiators, and, in addition, the LDR can be stowed compactly and is not subject to single point failure due to micrometeoroid encounters. The chief development issues for the LDR concern the performance of devices for generation of the droplet sheet and collection of the cooled droplets, and the configuration of the LDR to achieve optimum power to mass ratios. The present article describes recent progress in the tech- nology of droplet generation and collection for the LDR and discusses an LDR systems analysis which predicts LDR performance over a wide range of thermal powers and heat rejection temperatures. Among several existing methods of liquid atomization, the use of a multiple orifice plate (with each orifice producing a single droplet stream) has been examined most thoroughly as a method of LDR droplet sheet generation, because of the ability to produce highly colUmated streams of uniformly sized and spaced droplets. Since misdirection of droplets would result in unacceptable fluid loss and could create con- tamination problems, aiming accuracy is a paramount concern for LDR drop let generation. Experiments on the stability of droplet trajectories and the performance of multiple orifice arrays will be reported, which indicate that aiming accuracies better than 1 mrad are feasible. The droplet collector must capture the Incoming droplet streams and produce a continuous, pressurized liquid for reheating, with minimal losses due to backspiashing. Several concepts for droplet collection have been Investigated and an experimental centrifugal collection device to test some of these concepts will be described. Experiments on splash- Inhibition by porous target surfaces will also be reported. Fluid dynamic models of LDR components (generator, collector, droplet sheet, pump, manifolding) have been developed in sufficient detail to realistically predict their operational characteristics and masses. A computer code Incorporating these models has been used to study the in- fluence of parameters such as droplet size, droplet sheet geometry, temp- erature range, aiming accuracy, etc., on the performance and mass of an LDR system designed to reject a given thermal power. These optimization studies, which have been carried out for a range of LDR heat rejection applications, will be discussed. - 409 - « IAF-83-433

HIGH EFFECTIVENESS LIQUID DROPLET/GAS HEAT EXCHANGER FOR SPACE POWER APPLICATIONS

A.P. Bruckner and A.T. Mattick Aerospace and Energetics Research Program University of Washington Seattle, WA 98195 A high-effectiveness liquid droplet/gas heat exchanger (LDHX) for thermal management in space is described. Heat is transferred by direct- contact between a suitable low vapor pressure liquid, dispersed into fine droplets (MOO-150 ym diameter) and an inert working gas. Complete sepa- ration of the droplet and gas media in the zero-g environment is accom- plished by configuring the LDHX as a vortex chamber. The gas is admitted into the pillbox-like chamber tangentially at the periphery and spirals inwards to exit through a central axial manifold. Liquid droplets are injected radially outward into the swirling gas from the same manifold. The tangential momentum imparted to the droplets by the gas vortex gives rise to a centrifugal force which drives the droplets to the chamber peri- phery. The droplets impinging on this wall coalesce Into a rotating film which is drawn off through a series of collector si Its. Since the net gas flow is radially inward and the net droplet flow is radially outward, the LDHX behaves as a counterflow heat exchanger. Heat transfer in the LDHX can occur in either direction, I.e., gas can be heated by hot droplets or cold droplets can be used to extract waste heat from a working gas. The large heat transfer area presented by the multitude of droplets permits heat exchanger effectiveness in the 0.9-0.95 range in a very compact, lightweight geometry. The LDHX cir- cumvents many of the material limitations of conventional tube-type heat exchangers and does away with complicated plumbing systems and their ten- dency toward single point failure. A quasi-one-dimensional analysis of the LDHX 1s presented and para- metric studies aimed at developing optimal design configurations for a practical device are summarized. Experimental studies on a sub-scale de- vice are also described. The application of the LDHX in a high tempera- ture Brayton cycle is discussed to Illustrate its performance and opera- tional characteristics. - 410 -

IAF-83-436 SPACEt A Unique Educational Motivator

PETER A. SWAN CATHY W. SWAN Department of Department o-f Organization Engineering Systems and Strategic Studies School of Engineering Graduate School of Management Univ. of California University of California Los Angeles. Calif. Los Angeles, California USA 90024 USA 90024

Remember the excitement felt when you watched your first racket, launch? Was it a home built rocket, a Saturn 5 with Astronauts bound for the moon, or the mighty Proton launcher? This new era of the Space Shuttle, Spacelab and Salyut brings back te excitement that wo felt during the early days of space flight. Engineering marvels, managerial feats, technological break- throughs, and spin-offs are items of the past and goals for the future. The era of the 80's is sure to provide the new programs and necessary projects for governments; so lets uee these tools to insure education with excitement during the present and hopes for the future. Space, as the "top half" of the third dimension, provides challenges of the mind, new arenas for old laws, and unique pro- fessions for the future. Cooperation in space at the educational level could provide conduits of understanding that far outweigh the benefits of the space activities. Educational aspect* of the Shuttle missions should be shar*»d with the world along with the educational outputs of Spacelab .and Saylut. The experiments conducted by educational institutions and student* around the world should he shared to excite the young toward a tremendous future above the atmosphere. Who will be the Isaac Newton of Space Mechanics* who will be the Albert Einstein of Space Phy«ics» and who will be the Louis Pasteur of Space Chemistry? - 4-11 -

An excellent example of an educational institution exploiting the space environment -For enhancement of- educational goal* Iβ the United States Air Force Academy. Their Astronautice major is 23 years o}d| their preparation for Space Career* i* continuous! their teaching uses space examples) and their utilization of NASA* Get-Away-Special

IAF-83-438

Student Space Activity - Concept, Experience, Perspective Marcel Grtin

Department of Astronautics Observatory and Planetarium of Prague Czechoslovakia

The presented paper deals with the survey and scheme of student space activity in Czechoslovakia as it can be considered as a certain model /less or more convenient/ of involvement of students in space for a industrially developed small country. With the development of astro- nautics /previously reserved only for top science and technology teams/, the prospects for student space activity has been enlarged. And it has brought a need for incorporating of lessons on astronau- tics in the school education. Fundamentals of space science and technology is gradually and consistently implemented at curricula of the school system in Czechoslovakia - particularly at a course on physics at secondary schools. A text-book has been prepared co- vering the subject. Also booklets are published so as to keep instruc- tors with up-to-date information. In addtition to the school educa- tion, an attention is paid to the off-school education. In Czecho- slovakia, there is no astronautical society, and then most of its tasks is held by the dense network of observatories and planetariums originally aimed solely at amateur astronomers. At the present time, a certain portion - 15 per cent - of activity of observatories and planetariums is devoted to astronautics. The network is coordinated by the Observatory and Planetarium of Prague. The activity in this field is arranged in three streams: 1/ lectures dealing with latest developments in astronautics /basic level for wide public/, 2/ courses covering space science and technology /advanced level par- ticuiariy"for students/, and 3/ groups of space enthusiasts aspiring to their own projects /mem- bers are mostly graduates of courses/. In the following text we are going to pay our attention to graoups. The first group of this kind /SPACE/ evolved in the middle of six- ties. Currently there is the Liska Space Group /ISG/ sponsored by the Observatory and Planetarium of Prague /HaP/. LSG came into being in 1977 and its greatest successes are the first prizes in the under- graduate category of the IflF student conference in 1979 and 1982. The members of the group have been involved in the projects /among othres/ - Perun /Space Shuttle External Tank Used as a Space Station/ and spacecraft attitude control analysis. At present, LSG is engaged in solar sailing /Minimum Solar Sail Project/. The maiibers also par- ticipate in a professional space project. The other group under the HaP sponsorship performs since 1980 design, development and testing of payload for amateur sounding rockets. Within the framework of coordinating activity of HaP, we tries to establish similar groups throughout the network of observatories and planetariums in Czecho- slovakia and also to support student teams sponsored by universities /in areas like solar array technology, remote sensing, materials processing in space, etc/. Students can present their activity at the nation student conference on physics and/or engineering. Besides the managing and coordinating activity, we endeavour to find out problems in which student teams activity would be most valuable. Our attention is also kept at various aspects of ma- nagement schema of a student team that is essential for a success. It is also important to obtain the support of the national space organisation - Interkosmos Council in Czechoslovakia. IAF-83439

A Cooperative Educational Program in Aerospace Science and Technotofly for The High School and Middle School: Model for International Implementation

BETTYE B. BURKHALTER Auburn University, Alabama USA

MITCHELL R. SHARPE Alabama Space and Rocket Center HuntsviUe, Alabama USA National Air and Space Museum Washington, D.C.

ABSTRACT

In a time of educational unrest, traditional learning burn-out, and individual discontent, the State of Alabama offers an alternative. With the space age came a renewed search by Auburn University faculty to better meet,the needs of students by researching and trying innovative approaches to instruction which psychologists, learning theorists, and educators say promote learning. This paper presents several educational alternatives to educators which can be modified or replicated in an aerospace community, regular classroom, or varied learning situations.

The two programs presented focus on the experiential approach to learning and the partnership concept with education, government, and industry. Oftentimes called "active learning" or "hands-on-experiences," these programs offer innovative teaching methodologies and techniques that concentrate on the reality of experiential problem-solving. Both programs were empirically evaluated and proved to be successful at a statistically significant level. - 415 -

I A F - 83 - 440 OPERATING MODEL SATELLITE FOR SPACE EDUCATION

Author : G. PIGNOLET, Documentation Engineer CNES - Toulouee Space Center

A quarter of a century after the popular impact caused by the launch of Sputnik-1, satellite technology still remains a mystery for most of the population of the world, even in the technologically advanced countries, and even for most of the technically minded persons. One of the reesons is the obvious remoteness of the object to the common senses of man. Many persons have read papers about satellites, less have seen static mock-ups, but no one yet has "seen" a satellite in operation, even though the astronauts of the Shuttle have come close to it when they deliver one.

A psychological law tells that comprehension can only progress by reasonable quantum steps: if the steps are small, little progress is done in understanding, but if the steps are too large, people just "quit". In the case of satellites, the "gap" between the direct multisensorial experience of most people, and the remote reality of the satellite operating in orbit, is just too wide. Only space experts have the training and ths knowledge necessary to bridge this gap by a purely intellectual process. This situation can be di.igerous in the long term since it can widen an already existing divorce between the technical community and the general tax payer, and lead to difficulties in the development of space of the same nature as we have seen in the development of nuclear energy.

In an effort to "bridge" this comprehension gap, a successful attempt was made in 1982, to build an educational "operating" mock-up of a communication satellite, that could be easily and cheaply reproduced in schools and in youth clubs. Such a device is one of the ways to achieve these "intermediate steps" which will facilitate the comprehension of satellite technology. It will help the cooperation between the general public, who is both the initial tax-payer and the end user, and the space administrations and industries. The process is mostly profitable for those who built the mock-ups themselves, but later the models can be used for exhibitions and presentations to the general public.

By simulating the radio links with more visible light beams, and using material available from any general store, plus a few electronic components that can be bought from any radio shop, it is , possible to built a simple model that will incorporate most of the major functions and subsystems of a real satellite and of the associated ground stations. The construction takes one or two days of work for one person and simulates the actual integration process. It can be done by individuals but, from the educational point of view, group work will lead to a better overall understanding. - 416 -

To give a leverage to the educational aspect of the project, a booklet was prepared by the participants of the first workshop, where they relate their experience and help the future builders through the different* eteps, while leaving a lot of initiative for the actual realisation* It includes a general explanation on the operation of coaaunlcation satellites, and references for additional source*. Presently, the booklet is published in French, but it could be easily translated into any other langnage. No other coement can confire better the success of this process than the words of e school teacher at the end of a two-days session : "Mow, 1 caderstand better ..." _ 417 -

IAF-83-441 Forty Years of Supervised Student Rocketry; The Rocket Research Institute, 1943-1983 - A Memoir By George S. James National Science Foundation Washington, D.C. 20550 U.S.A.

ABSTRACT The Rocket Research Institute Inc., has been Involved In experiental programs for students and adults sincere early 1n 1943; when the world's largest rocket propulsion system was the yet generally unknown V-2; to today, where NASA pace Shuttle launches routinely carry student experiments as part of their payloads. The author, founder of the Institute 1n 1943, describes the highlights of past and present programs and outlines plans for the future of this private, non-profit, consulting organization, an 1AF Institution Member since 1968, which is staffed by professionally employed Individuals who volunteer their services to guide the development of safe and effective youth and adult oriented motivation and education programs related to the aerospace sciences. Safety 1s always the principal concern In all RRI education programs. The Institute firmly believes that experiential programs In supervised experimental rocketry can be undertaken only if the three factors of competent guidance, professionally designed equipment, and proper safety facilities are available. Thus, for decades, the RRI, Inc., has made Us facilities, resources and technical knowledge available to high school and college educators in addition to students engaged 1n programs of supervised experimental and model rocketry. These activities Incl de the design, construction, and evaluation of student fabricated rocket motors, payloads, and flight vehicles. Youth activities are organized under the Institute's National Rocketry Safety Registry (NRSR) program whose purpose is to help provide guidance; In cooperation with - 418 - industry, government agencies, educators, and parents; for the supervision of safe, educational, student space-science study and training activities in the three principal categories of youth programs, Student Astronautics, Supervised Student Model Rocketry, and Supervised Student Experimental Rocketry. A guiding principle of RRI educational programs is that experiential projects be available for all levels participants. The Institute's research facilities also are available to aerospace professionals who wish to enhance their experiential backgrounds through avocational projects of their own choosing. Such projects are mutally beneficial to not only the professionals but also, as an example, to students needing to fly experimental payloads on the propulsion systems developed by the professionals. New Institute facilities under construction for future programs will be described as will the programs which are to be conducted at these sites. The RRI's 40 year-old concept of experiential programs in supervised rocketry enters the 1980*s stronger than ever and even of greater usefulness in today's educational youth science motivation programs. IAF - 83 - 4 4 7 MANAGEMENT OF THE RADIOLINK OF THE SOLAR SAIL SPACECRAFT BY RADIO-AMATEURS

Authors : J.Y. PRADO, A, FERRET, J. V1LLAEYS Onion pour IΑ Promotion de la Propulsion Photonique 6, rue dee Remparts Coligny -31810 VENERQUB - FRANCE

A group oi French space engineers has created an amateur associa- tion in 1980, with the purpose of first, promoting a race of solar sail spacecrafts between the Eacth and the Moon, and then, to be one of the challengers by building its own spacecraft. ' This paper describes the present state of the technical studies, and presents the main features of the U3P solar sail* It considers especially the radio-link aspects, for which a call is addressed to radio-amateurs all over the world, asking their support for the design of the radio-link and TTC system, the realization of some communication equipments, and the organization of an amateur network for the operational support during the race. - 420 -

TITO rJATELLITB ACTIVITY OF THE RADIO SPORTS FEDERATION OF THE USSR A.V;Crorohov3ki Radio Sports Federation of the USSR The amateur radio satellite activity started in the IW!JR in 1978 when two experimental satellites "Radio-1" and "Radio-2" were launched. The operation of these satellites proved the basic principles of their design were ri^ht. So, a number of "Radio" satellites of second generation was build by RSP enthusiasts. On December 17, 1981 six such satellites were put on the orbit by one common carrier. These were "Radio-3" to "Radio-8" ( all "Radio" satellites are registered internationally as RS). Por the first time in amateur radio we have now in operation a space system consisting of six satellites, which offers vast opportunities for regular communication, experiments, competitions and, of course, for many appli- cations in the field of education. All six satellites fall into three categories with the features as follows: -"Radio-?" and "Radio-4" have, beacons operating around 29 MHz for the sake of measurment and education; -"Radio-5" and "Radio-7" have multi-purpose transpo- ders with up-link frequency around 145 MHz and down-link frequency around 29 MHz. They also have on board beacons, automatic "operators" ( so called "Robots" ) and memory units; -"Radio-6" and "Radio-8" have transpoders and beacons operating in the same frequency bands* The principal features of this satellite system is the possibility of simultaneous operation of four transpoders as well as availability of two "Robots" and memory units. During the first year of their operation the satelli- tes offered 23.000 hours of operating time via transpoders to amateurs throughout the world. Only Soviet amateurs established over 16.000 contacts durin 1982. "Robots" were in operation for more than 9*000 hours and amateurs of all six continents exchanged reports with these automatic space "operators". Also a number of competition type acti- vities took place Including "Cosmos-83" contest in April this year. In August, 1983 for the first time in amateur radio the portable-to-base stations contest will take place via satellites. Soviet amateurs also carried out some scientific expe- riments using RS-satellites. For example, on board of satellite a cardiogramm was transmitted froa amateur sta- - 421-

tion located in Antarctic.Stored in a memory unit, this cardiogramm was read back when satellite was over Moscow. The memory units were also regullary used for circular messages. To carry on the experiments on amateur radio space communication there were two small satellites "Iskra-211 and "Iskra-3" set in a low orbits by the crew of the "Salut-7' orbital station. They were developed jointly by students and amateurs. At present ESF is working hard to maintain in contin- uous operation existent amateur radio space communication system. Soviet amateurs are also looking for new systems such as high orbit satellites and transpoders on higher frequency bands. The Radio Sports Federation of the USSR comsiders it necessary for nearest future to concentrate efforts on the following items: -To encourage in every possible way the development of amateur radio satellite communication in the USSR and worldwide. The use of amateur radio satellites is by now far from being satisfactory, and RSP aim is to help it to grow up to the extent comparable with the use of most HF and VHP bands; -To provide for joint planning of use of all amateur radio satellite systems in operation now, taking into account the expected launches.

•\ - 422 -

IAF B3.455

Title : Cband radar calibration for Ariane launcher

Authors : J.P. CARROU and Y. LABRUNE

ORGANIZATION : CNES

Before the test flights of the european launcher ARIANt, CNES has orga nised a calibration campaign of radars located in French Guyana (KOUROUl and in Bra?il (NATAL). The aim of this paper- is first to present the means used for the catibra tion and explain the reasons of choice. We used : 1 - the american GEOS 3 satellite with 3 Interesting equipenients Cband radar transponder - laser reflectors - 162-324 MHz transmitter (for doppler measurements) 2 - the doppler receivers located in KOUROU, NATAL and TOULOUSE 3 - the US laser measurements 4 - the computing facilities of CNES" (in TOULOUSE and KOUROU)

We present the different problems encountered during the phases of pre- calibration, synchronisation of facilities and operational organization. Following this, we present the processing done to : obtain a good local set of orbital parameters with doppler measu rements - compare the orbit with laser measurements - Identify radar error models (vertically, perpendicularity, colli- mating, bias ...) - Identify radar e^ror models and orbital parameters within the same processing • obtain calibration by an internal method. - 423 -

The last part of the paper presents the results of the processing and the lessons learned by this campaign. The accuracy of identification obtained is s - ten to twenty microradlans for the parameters of error models, a few meters in range and some microradlans In angle measure (accuracy obtained at the end of final reduction)•

The main lessons concern : - preparing the campaign - synchronizing the means - choising a good adjustment for parameters (radars and orbits) - recommending a simple method for auto calibration less accurate but simpler to. achieve. - 424

I AT - Ml - ASh

f. TRACKING A w> OUR ft DFTFRHI NATION OK F.RS-I K.F. WakVer anil B.A.C. Amhrosliis Del ft University of Technology Department of Aerospace F.ngiiu>erInn

In 1987 KRA will launcli its first earth—Enervation K:Url!ll.> KB'; I Into » sun-synchronous orbit at an altitude of 778 km. One of the In- struments onboard (.be satellite is a radar'altimeter, which will, pro- vide measurements of the satellite's altitude above the mean sea sur- face with a precision of about 10 cm. To apply these data for deter mini tip, the ocean topography and Investigating large-scale currents, the satellite's orbit must be known -very accurately; for the radial position component an accuracy of 10-20 cm is ntrived for. This accu- racy level Is an extremely severe requirement for a satellite, with the physical characteristics of F.RS-1. encircling the earth In a re- latively low orbit.

At Pel ft University a study was performed to assess the accuracy with which the orbit of FRS-! can be determined, assuming that advanced Reometrlc and dynamic models are available, or will be derived from the tracking data, and applying a number of precise tracking con- cepts. Tills paper summarizes some parts of that study.

Orbit determination error analyses have been performed for 3-day,2- revolution and 15-minute arcs of tracking data. For the long arcs, global networks of laser range and TRANET doppler tracking stations were considered. Results are presented for networks of 14 and 6 laser stations, and 45, 16 and 5 TRANET stations. For the 15-minute arc, tracking by a regional network of 9, 5 and 2 laser and/or PRARF, ranging systems was considered. It is shown that, for the assumed accuracy of the available dynamic modele, global radial orbit ac- curacies of ">7 cm rms are achievable. For the center part of the 15- minute arc an accuracy of better than H cm may be attained.

It was found that for long-arc orhit determinations the gravity model uncertainty contributes most to the orbit errors. To demonstrate the power of tuning a gravity model to a particular satellite by proces- sing the tracking data of that satellite to adjust gravity model coefficients, results are presented for a case in which, from a single 1-day arc of TRANET doppler tracking data, selected subsets of coefficients are solved for. Tt is demonstrated that in that case the rms radial orhit error decreases to 47 cm.

Finally, the application of the satellite's altimeter as a tracking device is addressed. It is shown that If the altimeter measurements are sampled at an appropriate frequency from the eet: of dara gene- rated by the altimeter, the processing of these data In combination with laser range measurements acquired at only one or two ground stations may yield accurate orbits. With this very attractive, - 425 - centralized tracking concept a global orbit accuracy maybe realized which is comparable to that provided by processing the tracking data acquired by an extensive, costly network of ground stations. - 426 -

i./»!•-?. ••;?._'1!/'

Obrw.'f.t. i.(»TiM.l r'.qi.iu.lJ on for an Active J)npp.lor*H tiynton WCLli3<:rnur Jα!W i!part'< iiorm.-irch Centro I'oVJoh M;adr!ro.y of iJcieneenjY/nrsav; AM hii.rivluc+i'ir of observational equation for 1,1m deajp ncil ac I i vn iJoppl er's ayntem .in diocvianed in thl.a paper. In Uc nyyA.am rlonitTind, a t.]*finRriiJ.tter located at im olinor- vjvh i nn v iita.fr] oppler*a eya- t«.'f> a LM.'J.'O oliMorvatioiiftl oquat.ioji ltu.a boen introduood,ari'1 ac,rvvr:j tci-alyois of i-iettstu'cment tochnjqno liaa b(?en mado. ThT o i"'i I ' 1'VJ.iii;; Tvom of oliaorvationni equat t.on has been ob-

wliiu'o 13 ia thue obeorved value ai'd denotes tlie number o [%c or. r !, c"J eye1 03 of Dopp.l ex*f9 frequency ; ff is A mea- Burc!ncMit uffdet,tidtlod to a atotidard frequoncy jtTia an in- horv/j' o.r rrequoiicy Into^i-al.xcn; k is a coefficient of fre- ULicnoy du.pT i.cat J on on a aatnl Tito ; c in light velocity ;r a=!il r are dofcrmxnod radii rectoi'o observer - satellite.

i ('• rh'))ot(ii3 correci; i.on tonnf} f v/hinli conaidor propaga- tion l!r\> CJ'II iiiGtiMnnontaticm delays.AH it in soon from the .'-t" • ]i, tlio on.:;/- dotornined values ?j"e rad.il vectora, v/Jio- i v:i !.''o cojivoriti onul ay a torn th.e differonec of oatoiiit(! .LT-r(?j vfir atanOtu-fc "freauencien in doterinlnficl an v/eli . - 427 - IAIU83-459

Interferometric processing of BUSS Doppler observations^

I, Fejes, Sz. Mlhaly Satellite Geodetic Observatory 1373 Budapest Pf, 546, Hungary

Abstract: Simultaneously received transmission from MUSS satellites by two or more Ooppler receivers can be processed as interferometrie observables. The re- ceivers are physically unconnected and the coherence of the phase Information recordings /Doppler counts/ is ensured by highly stable independent local oscil- lators similarly as in VLBI* The purpose of the in- terferometric processing is to obtain high precision geodetic distance determinations using MSS Doppler data* - 428 -

IAF~8%460

SPFBCT OF THi COBFFICIBMT OF ERROR PROPAGATIOI • 0* 3ATELI.IT1 FOSIT1OI FIXIfO LIU ZB1-KOI taoyang Institute of Tracking aai Telecommunication Technology

ABSTRACT In thia paper tha method of controlling tha affact of the random arror of tha alaaante of a tracking ajetaa on tha statue paraaatara of tha trajectory or orbit of a epaoa vahiola la die. ouased. Tha ems af thia aathod ia to control tha arror propaga- tion eoaffioiant of tha tracking system. First, va dafinad thia ooafficlent, and next, tha propartiaa of tha eoaffioiant are die- cussed. Finally, tha apatial diatrlbutiona of tha arror propaga* tion eoeffIαlent ara plotted and the appliaatioaa in system selee- tian and utilisation ara diaeribed. Thia papar analyses threo.di- •anaional range measuring eyetea particularly. Tha corresponding ranga and range diffaranea ayatesj ia alao lnolnded ao that tha tvo ayeteas can be coapared. For lnetanteneous position fixing of distant apacaorafta, aneh aa tha geostationary oralt aatellite, with high accuracy, it la preferable to nee three-diaenaional ranging ayetea. We ean •et obtain the optimal site geometry with atatlone sited only in oar country, but alnoe oura ia a oountry with vmot territory, eoae reaaonable combinations af atatleaa one atlll ba established and a positioning accuracy af about 40((for tha geostationary orbit apaeecraft In eight eaa ba obtained. - 429 -

IAF - 83 - 461

SATELLITE RANGING INSTRUMENTATION DEVELOPED AT IIH

Ph. Hartl, N. Gieschen, W. Schafer, H.-M. SyIIwasschy, C.-M. Wintzer *) *) Technische Universitat Berlin, Instltut fUr Luft- und Raumfahrt (ILR)

The Institut fUr Luft- und Raumfahrt (ILR) of the Technical Universi- ty of Berlin is active in the design, development and production of ground-based and space-borne instrumentation for precise satellite tracking, principally by means of ranging. The paper describes 2 systems of very high accuracy developed at the ILR and based on the principles of tone ranging, and pseudonoise co- de ranging, respectively. Both systems are designed to1perform two- way ranging (ground-space-ground) through wide-band telecommunication transponders. The links require channel bandwidths of a few megahertz and can be established without mutual interference through transpon der channels occupied by ordinary telecommunications traffic. The systems developed feature hardware simplicity and low RF radiated power requirements. The paper presents results of laboratory measurements and field test results. Laboratory measurements of instrumentation performance pa- rameters show that resolutions in the order of some 10 psec can be achieved. Long-term drifts are of the same order of magnitude. The system design renders ionospheric delay errors negligible, and methods developed at the ILR allow modelling of the troposphere sufficient to reduce delay uncertainties to the same order of magnitude, i. e. of less than 100 psec. System accuracies depend further on the knowledge of the parameters (in particular delay, and delay an frequency stabilities) of the interfacing (at IF-level) RF ground station hardware, (converters, amplifiers, antenna equipment) and the space-borne transponders. ce+otT, .-.^curacies corresponding to overall delay errors of less than 1 nsec can be expected. A third system based on the developed pseudo-noise code ranging system and designed for a specific mission is under development at ILR. For this system both the ground instrumentation and the on- board hardware will be produced the system is described. - 430 -

The VLBI technique for Geodynamic Investigations V.S.Gubanov, N.D.Umarbaeva, P.A.JTridman Puikovo Observatory, I96I40 Leningrad,USSR

Abstract

The VLBI technique is suggested to be used ior obser- vations of radio beacons abord the near Earth space ob ject in combination with radio or laser ranging of thie objects. In this paper special features of VLBI observations of radio beacons are considered, and equations for the delay T and fringe rate F are obtained. On the base of mathematical simulation of observations estimations are given for possibilities of the application to finding of ground sites positions and orbit elements of satellite. In order to estimate the effectiveness of the VLBI method in combination with laser ranging at the stations of the geodynamic network, laser ranging of the same sa- tellite was included in the model scheme at one of the sites. The results of the calculations allow to make the following conclusions: 1) For satellites with altitudes less than 6000 km the fringe rate measurements are the most efficient. 2) Equations systes are found to be more stipulated if the problems of orbit elements improvement and the de- termination of sites coordinates are solved separately. However, both these problems can be solved simultaneous- ly by joint application of the VLBI and laser or radio ranging techniques, what is especially important for the initial stage of observations of a new object. 3) Laser ranging is more effective for satellites with altitudes more than 1000 km. 4) VLBI observations give more abundant and precise in- formation than laser ranging, except linear values, such as geocentric radius-vectors of stations and satellite, owing to strong correlations between them. This can be explained by the fact that the VLBI method ie differen- tial and requires introduction of a linear scale. This scale can be introduced by adopting the radius-vector of one of the stations as known or by adding the measure menta of the satellite distance from one of the sites to the VLBI observations of the satellite. 5) Most effective is the joint use of VLBI technique and laser ranging at the same geodinamical stations. The all-weather capability of VLBI allows to use it as a method without interruptions, laser ranging observations can be made from time to time in correspondence with technical possibilities and weather conditions. The let- ter limitation can be reduced by using radar location instead of laser ranging. Block diagrams and requirements to the ground equip- ment of VLBI stations for reception of various types of airborne signals are also considered in this paper. Ad- vantages and defects of employment of the following ty- pes of signals are analyzed: a) random noise signal (analogous to emission of extragalactic radio sources)j b) multi-frequency sinusoidal and c) complex-form deter mined signals (similar to the NAVSTAR - GPS satellte sig- nal). The accuracy of the T and F measurement for the above mentioned type of signals is given in dependence on the bandwidth of a receiver-transmitter system and the satellite altitude. It is shown that the most effici* ent type of the airborne signal is a multi-frequency si- nusoidal signal since it provides a high accuracy of mea- surements irrespective of the registration bandwidth. It makes it possible to simplify the receiving-proces - sing apparatus of the VLBI ground terminal and transmit the data over an ordinary telephone line,which is very important* - 432 -

SI-83-02

VI SO A! MAONITUDB ESTIMATION OP FRAGMENTED OBJECTS OP WOW INITIAL BRIGHTNESS BASED CM MODELASSOMPTIGNS ZΒ. PINTER Student of Lorand Eo*tvb*s University Budapest Dept. of Astronoay

Some objects of the Solar Systea can fall Into pieces in conseguence of different reasons, exerting an iaportant influence on the conditions of observation. The change of brightness can be estimated through approaching aodel cal- culations. Setting out froa the siaplest assumptions it's possible to attain aodels considering aore and aore real influencing factors, and at the same tiae to intend to reach better and better approximation of the real cases. The correction faotors, derived froa the observations, play an important part in applying the theoretical aodels to the possibilities of observation. The numerical investigation of the nodels is aade through algorisas, written on a personal computer. - 433 -

ST-83-04

OR THE THREE-DIMEKSIOHM, INVERSE PROBLEM

Student of Ebrand EbirUe Unirersity Budapest Dept. of Astronoay

The inverse problem generally neans to determine the un- known potential /or force/ froa known faaily ef cnrree of the notion. The planar inverse protlea has heen studied in the last years following Seetehely's aethod vAiioh offers a partial differential equation for the potential* A generalisation for three dimensions is inreetigated. We can get two partial differential equation* of the first order when a two-paraaetie faaily ef space ourres and the energy as a function of the paraaetres are giren. The condition for the solubility is derired ty a differen- tial geoaetrio aethod* Horeorer an explieit foraula is shovm to exist for the potential in the ease ef "non- degeneracy", fhe haraonlo oscillator is an exaaple for application of the aethed. 9tute-Space Analysis of the Dynamic Characteristioa of a Variable Thrust Liquid PropeiJont Rocket Engine

Zhang Yu-Idn Changsha Institute of Technology Changsha, Hunan, People's Republic of China

Abstract This paper 3tatea the application of state-space method to the analysis of the dynamic charcteristics of u variuble thrust liquid propel!ant rocket engine and presents u aet of state equations for describing the dyna- mic process of the engine. An efficient numerical method for solving those system equations ia developed. The theoretical solutions agree well with the experimental data . The analysis leads to the following conclusion: the set coefficient of the impulse width, the working frequency of the solenoid valves and the deviation of the critical working points of these valves are important parameters for determining the dynamic response time and the control precision of this engine. The methods develo- ped in this paper may be used effectively in the anaLysis of dynamic charcteristics of variable thrust liquid pro- PR Hunt rocket engines. - 435 - ST - 13th STUDENT CONFERENCE ST-83-O9

TELECOMMUNICATIONS AND THE SATELLITE "INTERCOSMOS - BULGARIA - 1300"

M.K. Serafimova /Summary/

In the application part of the "Intercosmos - Bulgaria 130011 satellite pro- gramme an apparatus is included for assessement of P field maximal electron concentrations /respectively their critical frequencies/ and their height dispo- sition by means of combined measurings of sky light andlocal electron concen- tration. Methods for determining the mean maximum structure of ionosphere for an exact assessement of m coefficient in MUF and for finding out other parameters, defining short waves diffusion, are discussed on the basis of these measurements. Absorbtional decrease of radio signals, passing through the so defined ^ionospheric structure is defined according to the satellite mea- surings . Polarizational losses of super high frequencies are calculated in the ranges used for satellite telecommunications on the basis of profiles defined for F field. The role of the precisely calculated by means of satellite measu- rings integral quantity of the Icm2 section electron pillar for a more adequate interpretation of bicon-measurings is stressed*

Margarita K. Serafimova -436-

ST - 83-10 Constructing mapping control from SEASAT-SAR images by photogrammetric means Rezs5 Berencei $r» Technical University of Budapest

Radar systems are active ones, they emit electromagnetic waves and reoeive these waves reflected from the terrain-surface. Synthetic aperture radar /SAR/ Images were attributed ever increasing importance in the past deoade. The reasons of this interest are the following: - making of radar-images is independent from diurnal and meteorological conditions; - the relief is imaged well, because microwaves penerate the vegetation. Radargramnetrio tools and technologies are developed singificantly. Application of radar-images in napping means the solution of following task-groups: 1) Creating (or developing) a mapping base (or control), analysing the image-deformations are geometric tasks and problems; 2) Analysing and evaluation of information-content of images is an interpretation task and appli- cation* Aβ a oomsequence of above mentioned, I studied first of all the methods of the radar imaglng-systems, wfcich are useful for mapping purposes* Among these, I analysed concretely the SAR-images made on board of satellite SEASAT-1, their geometric characteristics and deformations. Ky investigations were of photograarnetric type. I wish to review the course and results of these investigations. The schematic oourse was the following: - identifications of control-points, determination of their coordinates; -437 - establis hing the transformation-equntions; encoded storing of these equations; repeated plotting of different thematic conteife. - 438 -

ST-B3-1 3

nrcnoN OF SKEWKD REACTION WHEBW CONTHOM.KH FOR THRBB --. AXIS 3TABI LI ZED* SATELLITE Jin Liang Department of Automatic Control ChangSha Institute of Technology, China

ABSTRACT

In thia paper, a design procedure for an attitude control 3yatem consisting of four skewed reaction whools i« investigated. The altitude dynamics of the satolJJte ia doacribud by a controllable and observable linear, tJme — Invariant system. State feedback is

used ii. tin; i."iiitrul( with the state reconstriicted by a mlrirr.^l dimension observer. Control law is given by mlr.iir.lKln^ a quadratic criterion function.* The concept.:; of "uorm.il control" law and "failed control" law of 3kowo;l rii'totion wheol3*is introduced. It is shown that-, combination of correct distribution of torque commands can bo done using a simple network of distribution. The Influence of a flexible solAΓ cell pinto on the control lnw >»f skewed ruaction wheole is discussud. • * iui.ilyli rU ruu-ilts ara verified by oomput.gr "ainrtilati-»n. - 439 -

5T - 83 - 16 THE MARTENSITIC TRANSFORMATION AND SHAPE MEMORY EFFECT IN A NEW SPACE MATERIAL Yang Jianhua Harbin Institute of Technology, Harbin, China ABSTRACT The effect of Mn content on the transition tempera- tures, raartensitic morphology and substructure as well as the shape memory effect in a new space material of the Cu-Al-Zn-Mn-Ni type has been investigated by using resi- stance measurement, optical and electron transmission microscopy. Experimental results show that with increa- sing Mn content: (i) the transition temperatures are de- creased considerably and the temperature range of thermo- elastic transformation becomes wider, (ii) the martensitic morphology is improved from separately parallel plates to self-accommodating configuration, and (iii) the substru- cture of martensite undergoes a transition from twin to stacking-fault type. The decrease of cooling medium temperature has similar effect and promotes the overgrowth of martensitic variants. The Cu-10.31 wt?Al-3.82wt£Mn- 3.53wt$Zn-0.36wt/SNi alloy shows an optimizing potential as a new space material. The effect of cooling medium temperature on the maximum recovery ratio is shown in the figure below, and it may be explained by synthesizing the total effect of quenched-in vacancies, overgrowth of mar- tensitic variants and perfection of self-accommodation. The perfection of self-accommodation and overgrowth of martensitic variants are beneficial to the increase of recovery ratio, while quenched-in vacancies act unfa- vorably and the elimination of it must be considered in practical use. • *#

- 440 -

O •H

cu o o a)

a3 •ri

0 -200 -mo n mo soo Cooling medium temperature (uc)

Plot of recovery ratio vs cooling medium temperature I: C,.:-10wt|Al-3.53wtfr2n- G.76wt*Mn-0.36wt*Ni IT: Cu-1Owt$Al-3.53wt£Zn- 0.88wt*Mn-0.36wt*Ni III: Cu-10.31vUAl-3.82wt$Mn- - 441 -

II8L-83-02

THE GEOSTATIONARY ORBIT- SCOSPACB III

26th HSL Colloquium on the Law of Outer Spaoe I..1. 34-th International Astronautleal Conference Budapest, Hungary October 10-15, 1983

HOW. EIMARJ) R. PIHCH Member, International Astronautical Academy, International Institute of Space Law, International Astronaut, jcai Federatltm ft A.TAA Pinah 4 Schaefler, Attorneys 36 W. 44th Street New York,FY 10036, USA

Abstract — Increasing nse of the geostationary orbit has led to dales of crowding in this area. The importance of coordinating GSO use in order to avoid radio frequency interferences and possible collisions is emphasised. Bight basic Eeospaee principles of. outer space are reriewed as they were deTeloped i» Ecospace I /l/ and II /2/» Purther new basic outer space principles hare β-rolred in Kcospace TIT and are enumerated and explained in relation to the 1973 International Telecoaminlcatioas Union Conrention and the 1967 Outer Space Prinolplee Treaty, as well as in Q30 Resolutions of Unispace*82, now being implemented. This Scospace paper emphasises the importance of coweiistent.ly working from these common basic truths and econoialnp of outer space in reviewing, updating or creating outer space regimes.

i - 442 -

IISL-83-07 Communications in the Geostationary Orbit

The Missing Regulation l<. Terek

Transmissions from space stations, their frequencies end nominal orbital positions are very thoroughly r"gulri»*?«j by the 11U Kadio Keyulations and resolutions of th«? cplfVHiil UAkc tonferences. Space objects are, however, nut only abstract points in space from which transmissions emanate; they have also material presence, they can materially interfere with each other. There is no regulation of spare objects as material bodies, above the general provisions of the well known instruments of space law which apply to all space objects, whether they are in the GSO or in any other orbit.

The nain problem are possible collisions of space objects in the GSO and interference caused by close approaches There are three areas requiring fairly speedy regulation, if the GSO has to be preserved for its beneficial applications, in the first place for telecommunications. These are :

/I/ Removal of inactive satellites from the GSO before using up last supplies of propellent in station-keeping motors.

/2/ Reducing the amount of debris and non-functional objects in the 6S0.

/3/ Adoption of rules and arrangements for the sharing of the same nominal position by several active satellites.

The regulation of these areas is, strictly speaking, not within the province of the ITU and its Conferences. It would, however, be desirable if the international community agreed, at least tacitly, on extending the terms of reference of the ITU to cover the above subjects. As an alternative, these questions could be tackled by the UN Committee on the Peaceful Uses of Outer Space which has the item "Geostationary orbit" on its agenda. Unfortun- ately, too much time in that Committee and its Sub~Committees is devoted to an unproductive discussion of sovereignty over segments of the orbit while the above questions are very seldom mentioned. With the number of space stations in operation and planned for operation in the next few years in the GSO, time for adopting a useful regulation saving financial expenses and preventing accidents is running out. II8L-83-10 26th IISL Colloquium on Law of Outer Space IAP, Budapest, Hunqary, Oct. 10-15, 198 J

Applicability of Internationa] Law to Telecommunication Satellites in Geostationary Orbit and the Interest of the Develoninci Countries

by Charles Chukwuira Okolie, LI..M. , J.S.D. Okolie International Law Chambers, Chicaao, .U.S.A.

Abstract This paper bases its premise on the rapid, development of telecommunica- tion satellites. It discusses, in a summary form, the contributions made to the technology of communication satellites by the advanced space- exploring nations, and calls for a legal formula for the sharinq of the scarce "natural resource", i.e. the geostationary orbit positioning between the advanced soace technology states and the developing countries.

As a natural resource and a common heritage of mankind, the .-raostatio- nary orbit can be defined as an orbit understood by jurists and scien- tists as a circular orbit located at a distance of approximately 22,300 miles or 35,800 kilometers above the earth's equator. Thus, the oeo- stationary orbit being directly above the land mass of certain develop- ing countries, there arises a need for international co-ooeration in the sharing of the resources of this important soace orbit.

Specifically, this paper will examine the Third World concerns oertain- iner to the limitations of geostationary orbit as a corridor of physical size and uniqueness. The legal argument which we intend to employ in our analysis should reflect the concern of many scientists that the obvious limitations of Physical size of the geostationary orbit make it a "scarce" resource which should be conserved so that other nations not now having telecommunications technoloay will have spaces reserved for them for their future placement of satellites when and if ever these nations acquire the know-how and capability to launch their communica- tion satellites into a geostationary orbit. This research takes into account the United Nations estimate as to the number of satellites that can be accommodated in the geostationary orbit. Already there are many satellites operating in oeostationary orbit at present. If the nation states do not find means of control over these rapidly increasing numbers of satellites in space, there will be problems of electromagnetic interference with other satellites that transmit to the earth users of radio and television spectrum. -445-

The United Nations Resolution of December 10, 1982 pertainim? to "Acti- vities in the Field of International Direct Television Broadcastinq by Satellites" expresses the sentiments of the majority of the O.N. members. This resolution stipulates that activities in the field of direct inter- national television broadcastinq by satellite should be conducted in accordance with international law, including the Charter of the O.M., the Treaty on Principles Treaty on 27 January 1967, the relevant provi- sions of the International Telecommunications Convention and its Radio Regulations, and of international instruments relatinq to friendly rela- tions and co-operation among states and to human riqhts.

In view of the U.N. initiative and the economic benefits of telecommu- nication satellites technology, we intend to advocate commercialization of satellite business among states. In this process, transnational cor- porations will have the role of transferrins space technology to the developing countries on co.iunercial terms. As an alternative to the transfer of technology in this field, we will present other avenues for acquiring access to satellite business and co-ooeration based on the oremise of sharing of communication transoonders by states which now do not have their own space programs.

Finally, we will examine I.T.U. arrangements in co-ooeration by states regarding technological forces. We will integrate our thoughts with legal reasoning, hoping that such legal thoughts will qive us an oppor- tunity to discuss the process of molding legal norms throuah which better regulation of geostationary orbit will arise. - 446 -

IISL-83-37 "LIMITS TO STATE RESPONSIBILITY FOR SPACE ACTIVITY"

By Martin A. Rothblatt*

'Li.•> paper provides a comprehensive examination of the doctrine of state responsibility as applied to activities in outf-r space. The limits to state responsibility are discerned on the basis of an analysis of existing positive and customary interna- tional law, including the drafting histories of major treaties governing outer space activity. These limits are then operational 1v defined in terms of functional criteria which can be appij^j t.w planned spaca activities.

The formally discerned limits to state responsibilit.y for space activity are then applied to existing and proposed spac^ development projects. Limits to state responsibility for space activity are defined for space communications, remote sensing, space defense, space transportation, continuously inhabited orbital facilities, space manufacturing, lunar mining, asteroid retrieval, planetary modification and a generalized set of deep space activi- ties, including communication with non-Terran civilizations. Recommendations are offered which would provide for an evolving definition of state responsibility, gradually remove ambiguity from present definitions and facilitate space development.

* Member, IISL, AIAA; U.S.A. - 447 - 1NSTYTUT PANSTWA 1 PRAWA POLSKIEJ AKADEMJI NAUK VL. NOWY SWIAT 72 (PALAC STASZICA) 00-330 WARSZAWA INSTITUT de I'ETAT et du DROIT de I'ACADEMfE POLONAISE des SCIENCES

RrSZARD H A R A^ L.L.B. IISL-83-40 LEGAL STATUS OF ASTRONAUTS AMD RESEARCH PEHSONBtt ON THE MOON AND OTHER CELESTIAL BODIES

Man's venture into outer epaee besides opening a completely new dimension for human activities, has created numerous legal and political problems that have to be solved if peaceful exploration and uses of this space were to be secured* This aim could only be achieved through a creation of an international legal order that would regulate the activities of states in outer space, and any law-making processes in international law, if they are to be successful, require at least a minimum of states'cooperation* The amount of states* good-will and their willingness to achieve compromise, as displayed at the initial stages of drafting of legal rules governing the exploration of outer space, is probably unparalleled in the history of other great codifications of international law. Though later the ever increasing uses of outer spaoe have caused differences in the interpretation of the main provisions of the space conventions, but on the other hand, the need for cooperation in this field of international relations was never denied* Without the cooperation the fulfilment of one of the main aims of the Treaty on Principlee Governing the Activities of States in the Exploration and Use of Outer Spaoe, inoluding the Moon and other Celestial Bodies of 1967 Aater, in this paper, refered to as Space Treaty ot 1967/, that is , that the exploratimn and uses of outer space should benefit "all countries, irrespective of their degree of economic or scientifio development" /art.I.Jhe Spaee Treaty of i967/» could not be possible.' The protection of human life in thie etill unfriendly environment i> of oouree of primary importance for etatea involved in the exploration ot outer epaee. The recognition of astronauts "a* envoy* of mankind in outer epaoe" and the acceptation by the States Parties, to the Space Treaty of 1967, of an obligation to render them all possible assistance in the event of accident /art.V/ manifests olearly etatee concern with this issue, and their intention io secure a ainiaum %Z "'seessery cooperation in this field. The Agreeaeat on the Rescue of Astronauts, Return of Astronauts and the Return of Objejts Launched into Outer Ipace of 1968, futher specified states duties in this respect. Of special importance for the problem disceused in this paper is the article XII,$3 of the Draft Agreement Governing the Activities of States on the Moon and Other Celestial Bodies of 1979, which empowers States Parties to "Use the equipment, vehicles, instalations, facilities or supplies of other States Parties on the soon"in the event ef "an emergency involving a treat to human life", without an obligation to obtain a prior consent from the State Party whose facilities are being used. It is quite obvious that the practical implementation of this and other provisions conoerning the legal statue of astronauts may, in the near future, cause considerable controversies!for this problea involve* oae of the fundamental issues of the international law - the question of etatee jurisdiction in the se called "international spaces"* This paper attempts to evaluate the practical importance of provieione of epace treaties mentioned above. The "de legs farwadd' conclusions, concerned mainly with the further clarification of the legal status of astrenaute and other personnel on the moon are also inoluded. J - 449 - O.W. Hennigan, Jr. IISL-83-5O International Astronautical Congress October 10-15, 1983, Budapest, Hungary Cooperation in Space SECTION L. 26th I.l.S.L. Space Law Colloquium (4.) Legal Aspects of International Cooperation in Space

ABSTRACT International Control of Hazardous Earth Approaching Asteroids O.irJ. Hennifran, Jr.

Many theories exist to explain the sudden disappearance of the dinosaur. The most recent and by far the most fright- ening suggests that their extinction can be directly attrib- uted to a single tremendous meteor impact. The resultant de- bris cloud could have easily reduced the amount of light a- vailable at the Earth's surface to a level below that re- quired for photosynthesis for a period of several months. In- deed it is postulated that the sudden darkness may have ren- dered many animals nearly totally blind. The decreased light along with lowered global temperatures would have drastically limited the food supply of the herbivorous animals situated at key junctures of the ancient food supply chain. These in- terruptions may have lead to the demise of many species, in- cluding those of the giant reptiles, were such an impact to occur again in modern times mankind could well face the com- plete destruction of civilization as he now knows it, if not the total annihilation of the human race.

A small group of astronomers recognize this danger and have undertaken a preliminary survey to chart those interplanetary space objects most likely to present such a future threat. The vast majority of these asteroids orbit in a belt between Mars and Jupiter and so far approximately 50 one kilometer sized space objects have been determined to possess highly eccentric orbits that loop across the orbit of the Earth. These same astronomers have founded Project Spacewatch in order to further their indepth, comprehensive cataloging of these potentially cataclysmic space debris. In 1980 the National Aeronautics and Space Administration Advisory Coun- cil endorsed the Project Spacewatch concept on this very ground, suggesting that with enough warning an asteroid could be deflected with missies. The technical groundwork for this deflection attempt already exists on paper for in 1968 the Massachusetts Institute of Technology Student - 450 - o.rt. Hennigan, Jr.

Project in Systems Engineering published Project Icarus which in methodical and exacting detail laid out the technology and proceedures for deflecting an incoming asteroid on a direct collision couroe with the Earth. However, this study failed to pay any attention to those international organization and emergency international cooperative vehicles that would have to t>e erected to allow international consensus leading up to the deflection attempt. This problem is compounded by the clear fact that the best way to prevent collision would be to impact and detonate a nuclear device given its high energy yield to low payload mass ratio.

Granted that it is highly unlikely that an impact on the surface of this planet will ever take place, there nevertheless exists a growing body of evidence to indicate that this scenario has a basis in actual historical fact. Today mankind has both the early warning system to detect such an approaching asteroid as well as the technology to deal with it. Unfortunately the Earth does not possess a united people prepared to cope with this disaster. In the face of near total destruction what political problems might emerge to critically delay if not completely thwart any deflection attempt. This paper shall examine this scenario from the perspective of international cooperation based on the leading theories of international organization and international law. It will explore the models provided by present and future international space organizations designed to deal with this crisis. It will evaluate the effect, of international treaties that preclude the use of weapons of mass destruction in space as well as those which guar- antee that the space environment will remain free of man-made contamination. Lastly it will elaborate an the dangerous pre- cedent created by the placing of a nuclear device, albeit for peaceful purposes, in orbit above the surface of the Earth. - 451 -

IISL-83-51

"INTERNATIONAL COOPERATION IN SPACE'

This paper will attempt to put forth the institutional constructs for an international cooperative venture in space. While general aspects vd.ll be considered briefly, pre-qperational and transitional phases are presumed and discourse will focus on the operation of a manned space station on a permanent basis.

A proposal for an operative framework of international scape assumes several tasks. It must not only devise the most efficient means of aggregation and application of capital and technology but it must also offer methods of reconciliation of the conflicts implicit in the nature of the enterprise. The question of private versus govern- mental administration as well as alternative forms of organization will be examined. Existing entities such as the INTELSAT model will serve as points of reference.

Institutional goals will be discussed and the management policies best suited to achieve these goal's will be explored. The necessary body of legal regulation as required to maintain order and provide arbitration in the event of dispute will be recommended. Existing bodies of international space law will be applied and interpreted as relevant.

Because of the unprecedented nature of a,wholly interna- tional ccrmiercial space venture, cooperative guidelines will be asserted at the expense of competitive license. Competitive interests and practices have little construc- tive application in an undertaking of this scale in which concentration of resources and effort can achieve greater ends. Management policies of political, economic and ethical nature will be intended to encourage a coopera- tive operation and must not be frustrated by the dis- ruptive actions of competing interests. This paper will attempt a mediation of potential conflicts in pursuit of a common interest. In deference to the internationally accepted legal definition to date of space as the "coranon heritage" of mankind, the enterprise will also serve caimercial interests on a global scale. - 452 -

ABSTRACT 1984 IAF OCWFRRENCE PAPER

The writer liolds the opinion that space exploits ion prcjvides the opportunity for mankind to leave behmi its terrestial mistakes. The debilitating effects of divisive nationalism, territorial aggrandizement at*! ideological antagonisms which have sulivertfid orjnpprnf.iv*1 efforts on earth must not be carried in^o spare. The challenge presents infinite possibilities. If nwn is to be bound by narrow definitions and interpretatiixis of economic, ethical and political alternatives, intetna- tional ventures in space will meet with the same rteft'.i* of previous earthly efforts. Space affords man the chance to make not only his words but his aftions realize new dimension.

In conclusion then, this paper will advoiate an interna- tional organization which will manage mankind's space affairs once the exploration and research phases are over and the exploitation phase begins. An international organization that is founded by cooperative effort, built from global resources and designed for profit of global interests.

MR. A. MICHAEL HEWPJS VICE PRESIDENT AND GENERAL COUNSEL

MS. KRisrry L. NOTOR ASSISTANT

CORROON & BIACK INSPACE, INC. 600 MARYLAND AVENUE S.W. STB. 440 WASHINGTON, D.C. U.S.A. IISL-83-57

The Orbit/Spectrum Rt-r.ourre an a Collective Good Larry K. Martinez Department or Political Science University of California, Santa Barbara

The success of communications satellite systems has focused world attention up to the geostationary orbit and electromagnetic spectrum as global resources. Demand for satellite communications and a growing awareness by many countries as to their dependency on communications satel- lites had led to a perception of orbit/spectrum resource "scarcity". The perception of scarcity of both the geosta- tionary orbit and electromagnetic spectrum as used for satellite communications has politicized the resources. Upcoming ITU Administrative Radio Conferences, notably RARC-83 and Space WARC 85 and 87, will formulate a new glo- bal regime for allocating, regulating, and managing the increasingly valuable orbit/spectrum resource. The risk also exists that the conferences will instead fail to arrive at a majority consensus and will prove disruptive or destructive of the ITU's regime of international cooperation for orbit and spectrum allocation and use. Adopting the perspective of the orbit/spectrum resource as a global collective good pro- motes realistic proposals for a regime based upon coopera- tive resource management.

The orbit/spectrum resource is a global collective good owing to its "non-excludabilityM. Spectrum is universally accessible to anyone with even rudimentary technology. Effective and efficent use of the orbit/sp'ectrum resource is achieved only when all participants agree to follow basic rules and standards for use so as not to increase interfer- ence to other users. The "non-excludability" characteristic of collective goods, and the orbit/spectrum resource in par- ticular, behooves space powers to cooperate with developing countries to find a way to ensure "equitable access" to the resource for all participants. Nations who feel themselves barred from the benefits of satellite communications by a biased allocation system will not see a self-interest in cooperating and may even exploit the vulnerability of advanced nations to spectrum misuse. Paradoxically, the most advanced information-based economies are also the most vulnerable to belligerent uses of spectrum. Developing coun- tries can exploit this vulnerability as exemplified by Cuban jamming of the AM Broadcast Band in retalliation to Radio Marti.

An international regime based on the perception of the orbit/spectrum resource as a global collective good promotes rnti vv «)!'"•«• i on:; and use sinr<- ^11 participant:; "*-v their sp I f'-interest in cooperation rather thnn ••onf'r«inl»- t. ion. This p.iper will outline this per.spyl 5 VP find how "ii-m • fxnl tjilnbj 1 i i.v" of the resource and p.rowitip vii1nernbJ H t y \.u misuse can lead to an enlightened self-interest on the part of nations involved in the establishment of the interna- tional regime for the orbit/speetrum resource. - 4-55 - O.de Saint-Laser, France

HSL-83-64 LEGAL C01ISEQUENCE3 OF INTEHHATIOIIAL COOPERATION REGARDING REMOTE SEWS ING

Le d^bat sur les consequences juridiques dea activates dea Etata en matiere de t^leobservation de la Terra nerable aujourd'hui aingulierement obacurei par une apprehension parfois trop the"orique de la r^alit^ de la te"l

Or 1'apparition progressive d'une cooperation Internationale tres active, allant juaqu'a l'^raergence d'une veritable communaute observatrice, devrait pouvoir fnciliter 3a resolution des principalea questions juridiques encore en suspens. - 456 -

II3L-83-67 ABSTRACT

TOUAHt) SHARIC!) INTERPRETATIONS OF THK CRITICAL t'Ol.lCY DIMENSIONS OF SPACE LAW

Tin- p.-ist |ir;iit ice of slates and I In- dominant trends i i) fh.il priii-l ire show thai stiilcs have asr>um<:ii in their relations w i t li each other siitistnn tial .iri'.is of discretion, unregiilnled hy law- Tin-i r discretion is most prominently reserved tor the dei-l: ions, .ir Moris and policies ronrerning security, sell defense and measures of self help - nnd with respfil to amassing the weapons and military capabilities for those purposes.

Because the global order affords limited of .security, rill states have chosen to assume th.il responsibility for themselves. The law applicable at any given time to regulate; the use of coercion i dependent upon the organizational strength of. the community-oriented public order and its development

While states have the power to choose to strengthen the public order they share, and to promote through that process their mutual security, to do so imposes demands upon them to establish,

Harry H. Almond, .1 r. National(War College Washington, D.(t. 20319.

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- 457 -

DΓ Rer?flt-.ri Sznfsrz

Institute r,f St.'itp

Polish i-.cf^^my of

IISL-83-68 flevelonments in Efforts t.o

Sensing of the ^erth from

In thp opner there v\l~\ be

1. Tpytf? o^ soventppn rfrnft nrirciDles rss pontfiins'' in

of thp -Lpfal Sub-committPP on t.hn Vn'ork of ita

th £*ssion /UW DOc. A/AC. 105/^β, Annpy I,

together with?

?. WorVin/3: n^np.rs submittP'i h.y Go! ornH n snl Jdoyim to

Stib-coTimittpe at its tvc-ntipth oession /l9ei/»

3. Working onoprs suhmittpci by: Grepcp, Union of oovi^t Socialist

Hpnu^lics, Unitefl Stat.Ps of A'npriffi, Brazil Fin

thp Le;-al Sub-commit tpp fit. its twsnty-f irpt spssion /l9B'?/;

4. Working naners nnd other eroposals /if any/ submitted to the

Lpp-8l Sub-committee at its twpnty-spconrt ppssion /l983:^ocu-

mpnts st. ill not

In concl usion -tfc,e author will evaluate th» work

so far by the forking Grotm of the Lpfol Sub-committee in

the mstter in question. ISBN 963 372 135 0 Kiadja a KSzponti Pizikai Kutato Intezet Felelos kiado: Kovacs Tibor Peldanys2am: 1020 TSrzsszam: 83-553 Kesziilt a KFKI sokszorosit6 Uzemeben Felelos vezeto: Nagy Karoly Budapest, 1983. szeptember ho