Space Nuclear Power and Man's Extraterrestrial Civilization

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The Space Congress® Proceedings 1983 (20th) Space: The Next Twenty Years

Apr 1st, 8:00 AM

Joseph A. Angelo Chairman, Space Technology Program, Florida Institute of Technology, Melbourne, Fl 32901

David Buden Program Manager, Los Almos National Laboratory, Los Almos, NM 87545

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Scholarly Commons Citation Angelo, Joseph A. and Buden, David, "Space Nuclear Power and Man's Extraterrestrial Civilization" (1983). The Space Congress® Proceedings. 4. https://commons.erau.edu/space-congress-proceedings/proceedings-1983-20th/session-ic/4

This Event is brought to you for free and open access by the Conferences at Scholarly Commons. It has been accepted for inclusion in The Space Congress® Proceedings by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. SPACE NUCLEAR POWER AND MAN'S EXTRATERRESTRIAL CIVILIZATION

Dr. Joseph A. Angelo, Jr. Mr. David Buden Chairman, Space Technology Program Program Manager Florida Institute of Technology Los Alamos National Laboratory Melbourne, FL 32901 Los Alamos, NM 87545

ABSTRACT space exploitation—an era characterized by Operational flights of the Space Shuttle have routine manned access into cislunar space. initiated an exciting new era of space util,- Human technical development at the start of zation and habitation. In fact, the start the next millennium will be highlighted by of the Third Millennium will be highlighted the creation of man's extraterrestrial civil by the establishment of man's extraterres ization. There are several foundational trial civilization. There are three techni technical steps involved in the off-planet cal cornerstones upon which human expansion expansion of the human resource base. These into space will depend: include the development of reusable space transportation systems; the establishment of 1) compact energy systems, especially permanently manned space stations and bases power and propulsion modules; (initially in low-Earth-orbit and, eventual ly, throughout cislunar space); the develop 2) the ability to process extraterres ment of space-based industries; the creation trial materials anywhere in heliocen of lunar bases and settlements; and finally tric space; and the utilization of extraterrestrial re sources—as may be found on the Moon and the 3) the development of permanent human Earth-approaching Apollo/Amor asteroids. habitats in space. The Space Shuttle represents the United The manned and unmanned space missions of the States' commitment to the first step in this future will demand first kilowatt, then mega extraterrestrial expansion process, since watt, and eventually even gigawatt levels of operational Space Shuttle supports routine power. Energy, especially nuclear energy, manned access to near-Earth space. This will be a most critical technical factor in technical step will be followed by the crea the development of man's extraterrestrial tion of permanently manned space habitats- civilization. first in low-Earth-orbit (LEO) and then in other advantageous regions of cislunar This paper examines leading space nuclear space, such as geosynchronous orbit. Al power technology candidates. Particular though the early space stations in low- emphasis is given the heat-pipe reactor tech Earth-orbit would most likely depend on nology currently under development at the solar arrays for their initial power sup Los Alamos National Laboratory. This pro plies, nuclear reactors could eventually be gram is aimed at developing a 10-100*kWe, incorporated as such stations grow in size 7-year lifetime space nuclear power plant. and complexity—as for example, to satisfy As the demand for space-based power reaches increased power demands for materials proc megawatt levels, other nuclear reactor essing. Large space platforms at geosyn designs including: solid core, fluidized chronous-Earth-Orbit (6EO) could also bed, and gaseous core, are considered. effectively use nuclear reactors. In this application, the reactors would not only support the initial movement of massive plat INTRODUCTION forms from LEO to 6EO through the use of nuclear electric propulsion systems (NEPS), The highly successful test flights of the but would also serve as the platform's prime Space Shuttle mark the start of a new era of power source once operational altitude is

IC-1 achieved. Thus, in the 1990s and beyond, citing new era of space exploitation. Over advanced-design nuclear reactors could rep the next few decades, humanity will experi resent a major energy source for both space ence a subtle techno-social transformation power and propulsion systems. Some of the in which the physical conditions (e.g., high sophisticated space missions of tomorrow vacuum, weightlessness), resources (e.g., will require first kilowatt and then mega lunar and asteroid), and properties of outer watt levels of power. This paper explores space (e.g., view of the Earth, biological man's extraterrestrial civilization, and the isolation from Earth) are effectively used role energy, particularly nuclear, can play to better the quality of life for all on in the development of that civilization. Earth. This process has been called the "humanization of space."4»5 As part of this process, man (only a selected few at THE HUMANIZATION OF SPACE first) will also learn to live in space. Human progress is based upon challenge and The humanization of space is a complex de continued technical growth. As mankind velopment, which identifies the start of the enters the next millennium, expansion of the second phase of the Earth's planetary human resource base into space provides the civilization—expansion of the human pathway for continued material development. resource base into the Solar System.1»6 In fact, the overall development of civili The first phase of planetary civilization zation in the future depends on an ever- began with the origins of intelligent life expanding outlook--an "open world" philos- on Earth and will culminate with the full ophyJ»2,3 Its counterpart, a "closed- use of the terrestrial resource base. The world" philosophy for human civilization, third, and perhaps ultimate, phase of plane leads eventually to evolutionary stagna tary civilization involve migration to the tion. As demonstrated by the law of natural stars. Figure 1 displays some of the poten selection, once a life form has become fully tial technical steps that might occur durinq adapted, it achieves an intimate balance the second phase of the Earth's planetary with its environment. No further evolu civilization. 7 * 8 In this projected tionary changes occur, unless the nature and sequence of technical achievements, man characteristics of the environment itself first learns how to permanently occupy near- change. Exploitation of space, the ultimate Earth space and then expands throughout cis- frontier, however, provides mankind with an lunar space. As space-based industrializa infinite environment in which to continue to tion grows, a subtle but very significant develop and grow. transition point is reached. Man eventually becomes fully self-sufficient in cislunar Human civilization, forged and molded in the space--that is, those human beinqs livinq in crucible of challenge and adversity, must space habitats will no longer depend on the have new frontiers, both physical and psy Earth for the materials necessary for their chological, in order to flourish.1»3 For survival. Thus, from that time forward, without sufficient stimuli, individuals as humanity will have two distinct cultural well as entire societies would eventually subsets: terran and nonterran or "extra degenerate and experience an ever-decreasing terrestrial ". quality of life. Physical frontiers provide the living spaces and new materials with The final stage of this phase of planetary which to continue human progress. Psy civilization will be highlighted by the chological frontiers supply the challenge, permanent occupancy of heliocentric or inter variety, adventure, and outlet for creative planetary space. Human settlements will ap energies that make intelligent life inter pear on Mars, in the asteroid belt, and on esting. Unfortunately, this age is the selected moons of the giant outer planets. first period in human history in which there Finally, as humanity—or at least its extra are no new land or sea frontiers to be ex terrestrial subset—starts to fill the eco- plored and conquered on Earth. Only the sphere of our native star with manmade space frontier with its infinite potential "planetoids"—a cosmic wanderlust will also and extent can provide the challenge and op begin attracting selected citizens of the portunity necessary for continued, construc Solar System to the stars. With the first tive development of the human race. In a interstellar missions, the human race will closed-world civilization—that is, one re indeed become a galactic explorer—perhaos stricted to just a single planet--no truly as the first intelligent species to sweep new ideas, technologies, or cultures can through the Galaxy or perhaps destined to develop once all planetary frontiers have meet other starfaring civilizations! been crossed; only variations of old familiar themes can arise. THE NEED FOR ENERGY The operational Space Transportation System, Human development at the start of the Third or Space Shuttle, has now initiated an ex Millennium will be highlighted by the estab-

IC-2 lishment of man's extraterrestrial civiliza nuclear reactions. These reactions in tion. Three critical technical cornerstones clude: the spontaneous, yet predictable, that support this exciting development are decay of radioisotopes; the controlled fis currently perceived. These are: (1) the sion or splitting of heavy nuclei (such as availability of compact energy sources for Uranium-235, symbol 2 ^U in a sustained neu power and propulsion; (2) the ability to tron chain reaction; and the fusion or join process materials anywhere in the Solar Sys ing together of liqht nuclei 2 (such as deu tem; and (3) the creation of permanent human terium and tritium, symbols ]D and ^T re habitats in outer space.2»5 spectively) in a controlled thermonuclear reaction. The thermal enerqy so liberated Energy—reliable, abundant and portable—is may then be used directly in space system a critical factor in developing and sustain processes demanding large quantities of ing man's permanent presence in outer space. heat, or it may be converted directly into Space nuclear power systems, in turn, repre electrical power. Until controlled thermo sent a key enabling technology that must be nuclear fusion is actually achieved, nuclear effectively incorporated in future space energy applications will be based on radio- programs, if imaginative and ambitious space isotope decay or nuclear fission. applications and utilization programs are actually to occur in the next few decades.8 A generic space nuclear power system is de For example, the movement of large quanti picted in Figure 3. Here, the primary sys ties of cargo from low-Earth-orbit (LEO) to tem output is electrical enerqy, which is high-Earth-orbit (HEO) or lunar destina created by converting radioisotope decay tions, the operation of very large space heat or the thermal energy released in nuc platforms throughout cislunar space, and the lear fission into electrical enerqy, using start-up and successful operation of lunar static conversion (e.g., thermoelectrics and bases and settlements can all benefit from thermionics) or dynamic conversion (e.q., the creative application of advanced space the Rankine, Brayton, or Stirlinq thermonuclear power technology. Very imaginative dynamic cycles) principles. Contemoorary future space activities, such as asteroid options for nuclear energy heat sources and movement and mining, planetary engineering companion power-conversion subsystems are and climate control, and human visitations shown in Figure 4. While these options are, to Mars and the celestrial bodies beyond, of course, not all inclusive, they neverthe cannot even begin to be credibly considered less form the basis for intelligent planning without the availability of compact, pulsed of nuclear-power sources application for and steady-state, energy supplies in the space missions in the next decade and be megawatt and, eventually, gigawatt regime. yond. Radioisotope and nuclear reactor power systems—up to a few hundred kilowatts Since the beginning of the Space Age in the electric--are further classified in matrix late 1950s, a range of nuclear power supply format in Figure 5. For space-power appli options has been developed by the United cations in the megawatt regime and beyond, States to support civilian and military there are a number of possible advanced nuc space activities. Tomorrow's space program, lear reactor technology options. These keyed more heavily perhaps to applications designs include the solid-core nuclear and exploitation objectives, will require reactor (a derivative of the Rover program even larger quantities of reliable, long- nuclear rocket technology), the fluidized lived power. Nuclear energy judiciously ap bed reactor, and the gaseous core nuclear plied in future space missions offers sever reactor. al distinctive advantages over traditional solar and chemical space-power systems. These advantages include: compact size, US SPACE NUCLEAR PROGRAM light-to-moderate mass, long-operating life times, operation in hostile environments Since 1961, the United States has launched (e.g., trapped radiation belts, surface of over 20 NASA and military space systems that Mars, moons of outer planets, etc...), opera derived all or at least part of their power tion independent of the system's distance requirements from nuclear energy sources. from or orientation to the Sun, and in These systems and missions are summarized in creased space system reliability and auton Table I. As can be seen in this table, all omy. 9,10,11 i n fact, as power requirements but one of the previous missions used radio- approach the hundreds of kilowatts and mega isotope thermoelectric generators (RTGs) watt electric regime, nuclear energy appears fueled by Plutonium-238 (symbol 2 2§Pu). The to be the only realistic space power supply SNAP-1OA system was a compact nuclear reac option. (See Figure 2). tor that used fully enriched Uranium-235 as the fuel. The acronym "SNAP" stands for Space nuclear power technology involves the "Systems for Nuclear /\uxiliary JPower." Odd use of the thermal energy liberated by numbers designate radioisotope systems,

IC-3 while even number designate nuclear reactor converter. The lithium then condenses, and systems. is returned to the evaporator end of the heat pipe by the capillary action of the From the very beginning of the US space nuc wick. No pumps or compressors are used for lear power program, great emphasis has been heat transport. The fins around the heat placed on safety. Contemporary policy and pipes enhance heat transfer from the IK)? practices for all space nuclear power fuel to the heat pipes, reducing the tem sources promote designs that ensure that the peratures in the UC^. Surrounding the levels of radioactivity and the probability core is a containment barrel, which provides of nuclear fuel release will not provide any support to the fuel modules, but is not a significant risk to the Earth's population pressure vessel. The container also pro or to the terrestrial environment. For vides a noncompressive support for the radioisotope heat sources, this aerospace multifoil insulation. Multiple reflective nuclear safety policy essentially consists insulation layers reduce the core heat loss of providing containment that is not preju to an acceptable level. The reflector sur diced under any circumstances, including rounds the core and reflects neutrons back launch accidents, re-entry or impact on land into the fueled region. Located within the or water. For nuclear reactors, the safety reflector are drums that are rotated by mechanism consists of maintaining sub- electomechanical actuators. On part of critical ity under all conditions, normal and these drums is a neutron-absorption mate otherwise, in the Earth's atmosphere or on rial; the positions of this material are the Earth's surface. After the reactor has used to establish the reactor power level. experienced power operation in space, the reactor will be prevented from re-entering Power conversion in the SP-100 system is by the terrestrial biosphere. This is achieved the direct thermoelectric conversion of heat by ensuring that the reactor achieves a to electricity. Thermal energy is radiated final orbit that has a sufficient lifetime from the heat pipes to panels containing to permit the decay of fission products and thermoelectric material. Hot-shoe thermal other radioactive materials to levels that collectors concentrate the radiant energy no longer represent a radiological risk. from the core heat pipes. The heat is con Orbital lifetimes in excess of 300 years ducted through the thermoelectric material, support this aerospace nuclear safety producing electrical energy. Insulation is philosophy. used around the thermoelectric material to reduce the thermal losses. Heat that is not A typical space nuclear reactor power plant, used is radiated from the outside surface to such as pictured in Figure 6 consists of a space; this is the cold shoe component of nuclear reactor as a heat source, a radia the thermoelectric elements. By distribut tion attenuation shield to protect the pay- ing the thermoelectric elements over a wide load, the electric power conversion equip area with a sufficient number of elements, ment,, and a heat rejection system to the cold shoe becomes the heat rejection eliminate waste beat. radiator. Table II gives the characteris tics of a 100-kWe power plant. The power Figure 7 roughly classifies the leading plant weighs 2625 kg if improved silicon- technology candidates based on reactor type, germainium thermoelectric materials are conversion system, and heat-reject1on used, and less than 2000 kg with carbide or system. Heat-pipe reactor technology 1s sulfide materials. The overall length is currently under development In the SP-1QO 8.5 m for the earlier system. program. This program has a goal of de veloping a 10-100 icHe, 7-year-l1fet1me As depicted in Figure 7, thermoelectric con nuclear reactor power plant. This same verters are limited to the power-production reactor technology can be used for thermal region below 200 kWe because of the number power levels of 10-40 MM, of small modules involved and their low ef ficiency. From 200 kWe to the megawatt The reactor pictured in Figure 8 has a level, a choice of converters is possible centrally fueled core region made up of 120 between Rankine, Brayton, and Stirling fuel modules. These modules consist of a cycles, which would not require any increase heat pipe with circumferential fins attached in reactor temperatures. Thermionic con and fuel wafers arranged in layers between verters are another possibility, but would the fins. The heat pipes are used to trans require reactor temperatures several hundred port the reactor thermal energy to electric degrees Kelvin higher. Higher temperature power converters, and consist of a cylindri reactors increase fuel swelling and material cal tube, lined with a metal screen wick. problems. Converter efficiencies of 15 to Lithium, the working fluid, is evaporated in 30% are possible, but the higher efficien the reactor-fuel-module section of the heat cies lead to lower heat rejection tempera pipe. The vapor travels up the heat pipe tures. Because heat radiated to space until the heat is given up to the electrical

IC-4 follows a fourth-power relationship in tem than a few thousand degrees Kelvin, the ap perature (T4 ), high reject temperatures propriate nuclear fuel would be uranium tend to have much reduced radiator areas. hexafluoride, UFg. Above about 5000 K, As power levels increase, higher heat rejec uranium metal would be vaporized and ionized tion temperatures usually dominate the with the fuel as a fissioning plasma. At choice of converters. Although work has lower temperatures it is desirable, and at been performed on all these converters in higher temperatures it is necessary to keep the past, activity on space systems is no the gaseous fuel separate from the cavity longer ongoing. There appear to be no tech walls. This is accomplished through fluid nology barriers to power plants up to a few dynamics by using a higher velocity buffer megawatts, but active development is needed gas along the wall. Power is extracted by if any of the power options above a few hun convection or optical radiation, depending dred kilowatts are to be available to space on temperature. Gaseous core reactors offer mission planners of the 1990s. simple core structures and certain safety and maintainability advantages. The basic As the power-level demand expands to the research development was completed prior to tens-of-megawatt levels, solid core, fluid- program termination, including the demon ized bed, or even gaseous core reactors stration of fluid mechanical vortex confine might be considered. For space, solid-core ment of UF5 at densities sufficient to reactors were most extensively developed as sustain nuclear criticality. part of the nuclear rocket program. The Rover design featured a graphite-moderated, hydrogen-cooled core (Figure 9). The 93.15% SPACE INDUSTRIALIZATION 235u fuel was in the form of UC2 parti cles, coated with a pyrolytic graphite. The Space industrialization may be defined as a fuel was arranged in hexagonal-shaped fuel new wave in man's technical development in elements, coated with ZrC; each element had which the special environmental conditions 19 coolant channels. The fuel elements were and properties of outer space are harnessed supported by a tie-tube structural support for the economic and social benefit of system, which transmitted core axial pres people on Earth. Some interesting proper sure load from the hot end of the fuel ele ties of space include: hard vacuum, weight ments to the core inlet support plate. Sur lessness or "zero-gravity" effects, low rounding the core was a neutron reflective vibration levels, a wide-angle view of Earth barrel of beryllium, with 12 reactivity con and the Universe, and complete isolation trol drums containing a neutron-absorbing from the terrestrial biosphere.5,12,13 material. The reactor was enclosed in an aluminum pressure vessel. Electric power up Recent aerospace studies^?* 13 h ave at- to 100 MM could be generated by replacing tempted to look some fifty years into the the rocket thrust nozzle with power conver future and to correlate anticipated human sion equipment. This is a limited-life sys needs with growing space opportunities. tem, however. A low-power electric, long- These space industrial opportunities can be life mode could be achieved by extracting conveniently divided into four basic cate energy through the tie-tube support system. gories: (1) information services, (2) pro The Rover technology is ready for flight de ducts, (3) energy, and (4) human activities. velopment, having been tested in some 20 re (See Figure 11). actors. Peak performances are shown in Table III. In the full-scale exploitation of cislunar space, nuclear electric propulsion systems High-power requirements might also be met by (NEPS) will serve a critical enabling role fluidized bed reactors, in either the rotat in the efficient transport of massive, non- ing or fixed-bed forms. The former was in priority cargoes throughout cislunar space. vestigated as a rocket propulsion concept, In many missions, the NEPS will serve not and the latter has been proposed for space only as the propulsive means of placing a electrical power. A modest research effort massive payload in an appropriate operating in fluidized bed reactors was carried out orbit, but once the operational location is from 1960 until 1973. reached, the nuclear reactor would then service as the prime power supply for many Another candidate for megawatt-power re years of continuous, profit-making opera actors is a gaseous core reactor system. tion of the payload. Nuclear electric The central component of such a gaseous core propulsion systems could also be used as re reactor is a cavity where the nuclear fuel usable orbital transfer vehicles (OTVs) or is in the gaseous state. The reactor con "space tugs* 11 These propulsive workhorses cept shown schematically in Figure 10 is an of tomorrow would gently lift massive car- externally moderated cavity assembly that goes, supplies and! materials, large and contains the uranium fuel in the gaseous fragile payload s th*t had been assembled in phase. For temperature requirements less low-Earth-orbit, or even entire (unoccupied)

IC-5 habitats, and ferry these cargoes to their from hundreds of kilowatts (electric) to final destinations in cislunar space. Return several megawatts. voyages from lunar or geosynchronous orbit would witness these same nuclear electric vehicles carrying space-manufactured or THE MOON-KEY TO CISLUNAR SPACE selenian products back to the terrestrial markets. Finally, the continued, more The Moon is Earth's only natural satellite sophisticated scientific exploration of the and closest celestial neighbor. Relative to Solar System will also require nuclear elec its primary, it is extremely larqe. In tric propulsion systems as ambitious, ad fact, the Earth-Moon system might be re vanced exploration missions are undertaken garded as a "double planet" system. Not too to both the inner planets and the outer long ago, the Moon was only an inaccessible planets. celestial object—but today, through the technology of the Space Age, it has become a In a real sense, the information service "planet" to explore, exploit, and area of space industrialization already inhabit."14 exists. Space platforms are now providing valuable communication, navigation, meteoro To initiate the further exploration of the logical and environmental services to people Moon, we can first send sophisticated around the globe. Further expansion of such machines in place of men. For example, an services involves more massive platforms in unmanned lunar orbiter could circle the Moon orbit and much higher power levels. For ex from pole-to-pole remotely measuring its ample, current aerospace industry evalua- chemical composition, gravity, magnetism, tions'2J3 indicate that greatly expanded and radioactivity. This Lunar Polar Orbiter information transmission services from space mission would continue the scientific tasks represent some of the most beneficial in started by the Apollo Program and would pro dustrialization activities that could be ac duce extensive maps of the entire lunar sur complished in the next decade or so. A face. Automated lunar surface rovers would multifunction information services platform be used to make detailed lunar surface sur of the major capability is needed at geo veys, determining physical and chemical synchronous-Earth-Orbit. A baseline 6EO characteristics as well as searching for platform would require some 500 kilowatts potential mineral resources. These auto (electric) of power.8*12 This unmanned mated rovers, powered by radioisotopes (most platform would provide five new nationwide probably gzJPu) will be operated near the information services: (1) direct-broadcast poles, on the far side of the Moon and in TV (five nationwide channels, 16 hours per other interesting but previously unvisited day); (2) pocket telephones (45,000 private lunar regions. Then, when man himself channels linked to the current telephone returns to the Moon, it will not be for a system); (3) national information services brief moment of scientific inquiry as oc (using pocket telephone hardware); (4) curred in the Apollo Program, but rather as electronic teleconferencing (150 two-way a permanent inhabitant—building bases from , video, voice and facsimile channels); and which to explore the lunar surface, estab (5) electronic mail (40 million pages trans lishing science and technology laboratories, ferred overnight among 800 sorting centers). and exploiting the lunar resource base in support of humanity's extraterrestrial civi Another space industrialization opportunity lization. involves a Space Processing Facility in near-Earth-orbit. Designed mainly for zone Table IV suggests several stages of lunar refining and crystal growth, 12 this development and companion nuclear power re facility has fifteen furnaces capable of quirements. It is anticipated that the producing 750 boules of finished product first stage will involve site preparation every 60 days. The Space Shuttle would prior to the establishment of the perma service raw material magazines and return nently inhabited lunar base. Robotic sur finished "space-manufactured 11 products to face equipment controlled by orbiting space markets on Earth. The conceptual facility craft would prepare a suitable lunar site would be capable of producing 4500 boules for a permanently inhabited base of opera (weighing some 21,000 kilograms) of finish tions. One of the areas prepared would be ed products annually. A continuous power the site for the nuclear power reactors level of 300 kilowatts with a peak power re needed in Stage 2 of lunar development. quirement of some 550 kilowatts is projected. These remotely controlled robotic devices would be powered by radioisotopes (probably Geosynchronous-Earth-Orbit is also the 238p u ) enabling continuous operation favored location for a number of other Earth- throughout the full lunar day night cycle oriented applications and scientific plat (some 28 earth days). Radioisotope thermal- forms—both manned and unmanned. Power re electric generators (RTG), like the GPHS-RTG quirements for these systems would range with a specific power 5/3 Wkg, have proven

IC-6 to be rugged, highly reliable, and capable the growth of lunar expansion, finds of operating in hostile environments for markets throughout cislunar space, and may years at hundreds of watts levels of power. even export products to selected terrestrial With the creative use of dynamic power- markets. Power levels on the order of a few conversion equipment, as, for example, an or hundred megawatts electric would be needed ganic rankine cycle, the 6PHS could also be to support the processing of lunar materials capable of supplying kilowatts of power in and the operation of advanced transportation support of lunar-development activities. systems (such as surface electric monorails and mass-driver systems). An advanced de The initial permanently manned lunar base is sign nuclear reactor system is envisioned projected to have a habitat for 6-12 per with 30 year or more useful lifetime, on sons. To meet their power needs, a 100-kW line refueling, and robotic maintainability electric nuclear reactors (of the SP-100 features. Another characteristic of this heat pipe and core design) would support the new generation of lunar nuclear reactors -rnltral lunar base (see Figure 11). By the would be "walk-away sarety"—t^a t is, 1f a time man returns to the moon as a permanent malfunction should occur in any part of tf^ e inhabitant, these nuclear reactor units will power plant, it is so designed that no have a well-established engineering perfor operator action or even mechanical automatic mance on unmanned spacecraft and manned control mechanism is needed to achieve a space-station operations throughout cislunar safe condition. space. Of course, minor modifications of the basic reactor system will be needed to support manned lunar activities. For ex Finally, as the lunar settlement expands and ample, a 4 TT radiation shield could easily grows economically, a point will be reached be implemented using lunar soil material. when the lunar civilization, for all practi cal purposes, becomes autonomous of Earth. The initial lunar base, focusing on detailed Lunar products would be widely used through exploration in resource identification, will out cislunar space—the lunar economy, being then evolve into a multihundred-person early driven by the abundance of nuclear electric settlement. One of the main objectives of power, making full lunar-cycle productivity this early settlement will be to conduct a technical and economic reality. As part basic research and development, which takes of the full self-sufficiency experience in advantage of the lunar environment. Another Stage 5, a lunar nuclear fuel cycle will key objective will be the engineering demon also evolve, taking advantage of native stration of prototype processes upon which a Uranium and Thorium minerals, as well as the viable lunar economy might eventually be classic breeding reactions involving fertile based. Expanded versions of the SP-100 heat- and pipe reactor, coupled to more efficient power-conversion systems such as Brayton, Stirling, or Rankine cycles, would provide SUMMARY megawatt levels of electric power to the early lunar settlement. If man is to expand beyond his terrestrial womb and assume his proper role in the cos In Stage 4, the early lunar settlement mic scheme of things, he must have abundant, matures and economically exploits processes compact, and reliable energy supplies to ac developled in Stage 3. Lunar products feed company him on his journey beyond the Earth's atmosphere. Nuclear energy, properly de veloped and used, is the sini qua non for manned extraterrestrial civilization.

IC-7 REENTRY

SURFACE SURFACE SURFACE

SURFACE SURFACE

RETRIEVED

MOON.

JUPITER

JUPITER,

JUPITER JUPITER AND

SOUTH PACIFIC

LUNAR LUNAR LUNAR

MARS

LUNAR LUNAR

MARS

TO TO

ORBIT TO

ORBIT SOURCE

ORBIT ORBIT

ORBIT ORBIT ORBIT

ORBIT

ON ON

ON ON ON

WAY

HEAT

BURNED

STATUS

^LACED

PLACED PLACED

ACHIEVED

dPERATED

ACHIEVED ACHIEVED PLACED ACHIEVED OPERATED ACHIEVED

\CHIEVED ACHIEVED

PLACED

LANDED

OPERATED

ACHIEVED

OPERATED

BEYOND

RETURNED

AND

ABORTED: ABORTED:

ABORTED

(1961-A982)

SATURN

SUCCESSFULLY HEAT SOURCE SUCCESSFULLY SUCCESSFULLY SUCCESSFULLY SUCCESSFULLY SUCCESSFULLY

BEYOND SATURN, AND SUCCESSFULLY SUCCESSFULLY SUCCESSFULLY SUCCESSFULLY SUCCESSFULLY SUCCESSFULLY SUCCESSFULLY SUCCESSFULLY AND

SUCCESSFULLY OCEAN. SUCCESSFULLY MISSION SUCCESSFULLY SUCCESSFULLY SUCCESSFULLY

MISSION

U.S.A.

BY THE

1963

1977 1975

1972

1969

1961

1971 1972

1963

1975

1977

1976

5, 1964 1972

1969 1970

2, 9,

28,

1971 14, 1972 1973

1965 1961 15, 7,

1968

31,

20,

DATE

LAUNCHED

14,

16,

14, 5, 11,

21,

26,

29,

18,

TABLE

SEPTEMBER

JANUARY JULY NOVEMBER

APRIL APRIL AUGUST SEPTEMBER JUNE MARCH DECEMBER APRIL DECEMBER

LAUNCH SEPTEMBER NOVEMBER APRIL AUGUST SEPTEMBER MARCH

APRIL MAY

APRIL

SYSTEMS

POWER

TYPE

NUCLEAR

PLANETARY

PLANETARY PLANETARY PLANETARY

NAVIGATIONAL LUNAR EXPERIMENTAL NAVIGATIONAL NAVIGATIONAL LUNAR COMMUNICATIONS LUNAR LUNAR NAVIGATIONAL LUNAR NAVIGATIONAL LUNAR

MARS

NAVIGATIONAL

MARS METEOROLOGICAL

MISSION

METEOROLOGICAL

SPACE

-IX)

4A 4B

III

15 17 13

2 14 12

8/9

SUMMARY

(TRIAD-01

"TRANSIT"

VIKING VIKING LES

VOYAGER

NIMBUS-B-1 NIMBUS VOYAGER PIONEER PIONEER

TRANSIT-5BN-3 APOLLO TRANSIT

SPACECRAFT SNAPSHOT APOLLO TRANSIT APOLLO TRANSIT-5BN-1 APOLLO TRANSIT-5BN-2 APOLLO

APOLLO

(REACTOR)

-2

RT6

SNAP-9A SNAP-27 SNAP-19 TRANSIT- SNAP-3A SNAP-27 SNAP-9A SNAP-27 SNAP-19 SNAP-19

SOURCE SNAP-19 SNAP-19B2 SNAP-3A SNAP-1963 SNAP-27 SNAP-27 POWER SNAP-9A SNAP

SNAP-IOA

MHW

MHW MHW

o Cycle

Ganymede]

Supply

Design)

THE

SP-100

Design)

Design, Lunar

Reactor

Reactors

Fuel

range]

modification]

persons]

Power

TWO

Probable Nuclear

(RTGs)

(SP-100)

Radioisotopes (Advanced Nuclear

(Advance

Expanded

(Advance Nuclear

Nuclear

[6-12

climate

persons]

[e.g., Titan,

Space

PHASE

REQUIREMENTS

[megawatt

"Astropolis"]

CIVILIZATION

persons]

Space

Depot

GEO

Space

Center

Space

Level

Asteroids

[e.g.,

Moons

POWER

kWe

MWe

[6-12

persons]

[200-300

KWe

MWe

STEPS

Facility

AND

Vehicles

Ehricke's

PLANEIARY

Power

GEO

persons]

Belt

-100

Service

-100

few

-1

Cislunar

Hundreds

Electric Complete

Planet

Heliocentric

Megawatts

[6-12

Cislunar

Near-Earth

Cislunar

Heliocentric

Programs

Earth Orbit

and

Operations

TABLE

Launch (nuclear)

persons]

[6-12

Krafft

Apollo/Amor

Missions

(1992-2092)

Settlements

Outer

EARIH'S

POTENTIAL

Transfer

Settlements

Base

Asteroid

Station

the

DEVELOPMENT

Base

Station

1. Exploration

Platform

[e.g.

Plants

Throughout

[50-200

Orbital

Lunar

Martian

Engineering

Occupancy

Propellant

Occupancy

Lunar

Orbital

Occupancy

Belt LUNAR

SeTected

Lunar

"Planetoids"

Martian

Preparation Space

Bases

Station/Space

Base

Figure

Power

Base

Communities

Cities

Interstellar

persons)

OF on

(Self- Settlement

Orbiting

Settlements Self-Sufficiency

Lunar

Site

persons)

Space

Space Near-Earth

Initial

Orbiting

>10

Large

Manned Orbiting Cislunar Permanent

Lunar

Space

Extensive

Settlements Initial

Utilization

Permanent

Mars

Asteroid Bases Permanent Planetary

Manned

Manmade First

Permanent

Full

Lunar

Permanent

STAGES

Lunar

persons)

o o o

o o

o o o

o o

Initial

(6-12

Automated (lO^-IO^

Early

(102-1Q4 persons)

Mature

Civilization

Autonomous Sufficient

Economy:

STEP

100

1990s

507 128

- 100

10 950

7.0

4.3 43

18.

1837

2556

5.56

5.79 4.28

6.48

370 670 155 195 215 165

Pewee-1

1805

Early

-2A

137

4080

1600

2.3

119.2

2283

3.83

2256

5.39

4.73

100

Phoebus

- 100

1480

8.5

4.3

38 80

1980s

SUMMARY

790

405

375

450

285

240

2625

200

Late

PERFORMANCE

MASS

128

0.4

lib/

32. 2472

2342

4.96 5.19 4.13

NRX-A6

III

ANO

TESTS

TABLE

(kg)

SYSTEMS

104

950

?.o

PERFORMANCE

1980

2230 3.49

31,8

4.02

4.32

Design)

KIWI-4BE

(kWt)

Mass

REACTOR

SP-100

panels)

(K)

(m^)

Power

Reference

end

(K) (MPa)

(W/kg)

System

(kWe)

Design

(10%)

(MPa)

(yr)

(max)(m)

(at

area

Temp

Pres

Insulation

(K)

(m)

(MW)

Struc

Total

Power

Thermal

Dimensions

Pipes

(kg/s)

Power

Life

Mass

Temperature

Pressure

Conversion

(kg/s)

Inlet

Average

and

(including

(K)

Power

Temperature

Pressure

Nominal

Range

Design Power

Total Range

Reference Length

Diameter Thermal

Radiator

Shield Heat

Reactor Structure

Radiator

Flow

(MPa)

Inlet Inlet

Exit

Rate

Output Design Reactor

Overall

System

Specific

Temperature

tural sure

erature

Core Fuel Chamber Reactor Core Flow Chamber

Periphery

Reflector

Reflector REGIMES OF POSSIBLE SPACE POWER APPLICABILITY

NUCLEAR REACTORS

\ RADIOISOTOPES A

Ill

1 min 1 HOUR 1 DAY 1 MONTH 1 YEAR 10 YEARS DURATION OF USE

Figure 2

GENERIC SPACE NUCLEAR POWER SYSTEM

REJECTED THERMAL ENERGY

PRODUCTS OF NUCLEAR PROCESSES

THERMAL ENERGY-TO ELECTRICAL ELECTRICAL ENERGY ENERGY OUTPUT CONVERSION

DIRECT THERMAL ENERGY UTILIZATION FOR HEATING, COOLING OR IN HIGH THRUST PROPULSION SYSTEMS

Figure 3

IC-10 OPTIONS COVERED IN SPACE NUCLEAR PROGRAM

RADIOISOTOPE FUELED

HEAT SOURCE

REACTOR (235,j)

Thermoelectrics STATIC p Thermionic Converter

POWER CONVERSION Brayton Cycle Turbine/Generator

DYNAMIC Organic Rankine Cycle Turbine/Generator

Stirling Cycle/Generator

Figure 4

CLASSIFICATION OF NUCLEAR POWER SYSTEM TYPES BEING CONSIDERED FOR SPACE APPLICATION

ELECTRIC POWER RANGE NUCLEAR POWER SYSTEM TYPE (MODULE SIZE) POWER CONVERSION

RADIOISOTOPE THERMOELECTRIC Up to 200 We STATIC: THERMOELECTRIC GENERATOR (RTG)

RADIOISOTOPE DYNAMIC 0.5 kWe - 2 kWe DYNAMIC; BRAYTON OR CONVERSION GENERATOR ORGANIC RANKINE CYCLES

REACTOR SYSTEMS 10kWe- 100 kWe STATIC: THERMOELECTRIC (HEAT PIPE)

REACTOR SYSTEM 1 - 10MWe BRAYTOISi CYCLE HEAT PIPE RANKINE CYCLE SOLID CORE STIRLING CYCLE

BRAYTON CYCLE REACTOR 10- 100 MWe SOLID CORE (OPEN LOOP) FLUIDIZEDBED STIRLING GASEOUS CORE MHD

Figure 5

IC-ll

m o o

0.0.

§12

or*

REACTOR REACTOR CONVERTER CONVERTER (AREA (AREA m 2 )

REJECT REJECT HEAT HEAT 21-31

weather weather

new new

navigation, navigation,

glasses, glasses,

resources, resources,

time, time,

environmental environmental

services, services,

water water

perfect perfect

Space"]

...]

of of

INDUSTRIALIZATION

resources, resources,

fibers, fibers,

...]

teleoperation, teleoperation,

mail, mail, news

management, management,

SPACE SPACE

and and

sanitarium sanitarium

University University

...]

OF OF

...]

mineral mineral

forest forest

"The "The

urokinase, urokinase,

electronic electronic

Space

AREAS AREAS

high-strength high-strength

and and

in in

magnets, magnets,

hospital, hospital,

surveys, surveys,

aid, aid,

[i.e., [i.e.,

Arts

...]

MAJOR MAJOR

crop crop

Laboratories

Research

telemonitoring telemonitoring

use use

isozymes, isozymes,

Space

the the

crystals, crystals,

11. 11.

ocean ocean resources,

Research Research

land land

medical medical

solar]

and and

rescue, rescue,

from from

Transmission

Education Education

Genetic Genetic

Space Space

or or

SERVICES

high-strength high-strength

and and

resources, resources,

single single

"zero-gravity" "zero-gravity"

Scientific Scientific

Figure Figure

Fusion Fusion

and and

climate, climate,

From From

Therapeutics

Tourism

Acquisition

ACTIVITIES

[education, [education,

and and

[Earth [Earth

[biochemicals: [biochemicals:

search search

[nuclear [nuclear

teleconferences, teleconferences,

alloys, alloys,

[large [large

monitoring, monitoring,

[e.g., [e.g.,

Information Information

Inorganic

Illumination Illumination

Data Data

Power Power

Nuclear Nuclear

Organic

Space-Based Space-Based

Space Space

Orbiting Orbiting

Entertainment Entertainment

Space Space

Medical Medical

INFORMATION INFORMATION

- -

PRODUCTS

- -

ENERGY

- -

HUMAN HUMAN

- -

0 0

PINS, PINS,

OF OF

COOLANT

FUEL

DRIVER

FUEL FUEL

MATRIX)

WALL

CAVITY CAVITY

(PLATES, (PLATES,

ELEMENTS ELEMENTS

DRIVER DRIVER

PROPELLANT

EXAMPLES EXAMPLES

Reactor Reactor

Core Core

FEED

Concept

Gaseous Gaseous

10, 10,

URANIUM URANIUM

Figure Figure

SHELL

PRESSURE PRESSURE

OXIDE OXIDE

MODERATOR MODERATOR

REFLECTOR

BERYLLIUM

DRIVER

FUEL

COOLANT

i o o

Power

Nuclear Nuclear

With With

Base Base

Lunar Lunar

12. 12.

Figure Figure

I o o