i t_ "'//v NASA Technic_a| Memoranduffi- I062_J1 ........... AIAA-93-2278 ...... Space TransportationAlternatjves for Large Space Programs: The International Space University SummerSession- !992 Bryan A. Palaszewski Lewis Res_earch Center._ Cleveland, Ohio Prepared for the 29th Joint Propulsion Conference and Exhibit cosponsored by the AIAA, SAE, ASME, and ASEE Monterey, California, June 28-30, 1993 (NASA-TM-I06271) SPACE N94-I0811 TRANSPORTATION ALTERNATIVES FOR LARGE SPACE PROGRAMS: THE INTERNATIONAL SPACE UNIVERSITY Unclas , .: SUMMER SESSION t I992 (NASA) 25 p _,:...._., PT G3/16 0175557 _T . Space Transportation Alternatives for Large Space Programs: The Intemational Space University Summer Session - 1992 Bryan Palaszewski* National Aeronautics and Space Administration Lewis Research Center Cleveland, OH Abstract. Nomenclature In 1992, the International Space University CAN Canada (ISU) held its Summer Session in Kitakyushu, DOE Department of Energy Centre Nationale d'Etudes Japan. This paper summarizes and expands CNES upon some aspects of space solar power and Spatiale space transportation that were considered during EOTV Electric Orbital Transfer that session. The issues discussed in this paper Vehicle are the result of a 10-week study by the Space ESA European Space Agency Solar Power Program design project members ETO Earth to Orbit and the Space Transportation Group to EVA Extravehicular Activity investigate new paradigms in space propulsion FRA France and how those paradigms might reduce the costs FY Fiscal Year for large space programs. The program plan was GEO Geostationary Earth Orbit to place a series of power satellites in Earth orbit. GPS Global Positioning System Several designs were Studied Where rnany kW, GW Gigawatt MW or GW of power would be transmit_d to H Atomic Hydrogen Earth or to other spacecraft in orbit. During the HLLV Heavy Lift Launch Vehicle summer session, a space solar power system was ISAS The Institute of Space and also detailed and analyzed. A high-cost space Astronautical Science transportation program is potentially the most ISU International Space University crippling barrier to such a space power program. IUS Inertial Upper Stage At ISU, the focus of the study was to foster and Isp Specific Impulse develop some of the new paradigms that may JETRO Japan External Trade eliminate the barriers to low cost for space Organization exploration and exploitation. Many international JPL Jet Propulsion Laboratory and technical aspects of a large multinational JPN Japan program were studied. Environmental safety, kW Kilowatt space construction and maintenance, legal and LSS Large Space Structures policy issues of frequency allocation, technology METS Microwave Energy Trans- transfer and control and many other areas were mission in Space addressed. Over 120 students from 29 countries MILAX Microwave Lifted Airplane participated in this summer session. The results Experiment discussed in this paper, therefore, represent the MTNIX Microwave Ionosphere Non- efforts of many nations. linear Interaction Experiment * AIAA Member, Copyright © 1993 by the American Institute of Aeronautics and Astronautics, Inc. No Copyright is asserted in the United States under Title 17, U.S. Code. The U.S. Government has a royalty-free license to exercise all fights under the copyright claimed herein for Government purposes. All other fights are reserved by the copyright owner. M1TI Ministry of international optimistic incarnations, it can provide almost Trade and industry unlimited power for all of the world's MPD Magneto Plasma Dynamic industries. Finding where the truth lies will MSS Master in Space Studies require more thoughtful consideration. MW Megawatt NASA National Aeronautics and Space Solar Power_Background Space Administration and History_ NLS National Launch System OTV Orbital Transfer Vehicle During the early 1960's, several researchers PLV Personnel Launch Vehicle considered the possibility of collecting POTV Personnel Orbital Transfer energy from the Sun and transmitting it to the Vehicle Earth. Peter Glaser (Ref. 6) was the first to SDI Strategic Defense Initiative propose and patent the idea of beaming solar SEE Societe des Electriciens et des energy from a satellite to Earth. Some of the Electroniciens first experiments with ground-based beamed SFU Space Flyer Unit energy were conducted with a small-scale SHARP Stationary High Altitude helicopter (Ref. 7). JPL and NASA Relay Platform conducted other larger scale demonstrations SPS Solar Power Satellite of the technology for power beaming in the SSPP Space Solar Power Program atmosphere. Amongst these are the world's SSTO Single Stage to Orbit highest power level transmitted by STS Space Transportation System microwave beam through the atmosphere TSTO Two Stage to Orbit (Refs. 8 and 9). A total of 30.4-kW of USA United States of America beamed power was received at the NASA- JPL Deep Space Network Station in Goldstone, California. An array of lights IntrogI¢ction were illuminated from a distance of 1540 meters. Space power has been studied in the past as an alternative to terrestrial power systems (Refs. 1, The NASA-DOE study (Refs. 2, 4) 2, 3, 4, 5). Its attractiveness lies in the thought investigated large scale 5-GW power level that because energy is produced in space, the solar power satellites. Detailed conceptual thermal and material pollution of the Earth can be designs of all of the components were substantially reduced. Also, because these developed over a period of 5 years from power stations are in space, there is thepotential 1976-1980. Dozens of these satellites would for continuous power. With no cloud cover, be needed to power the USA or any other storms or other weather to obscure the solar large industrial user nation. All of the radiation, power can theoretically be generated 24 satellites would operate in Geostationary hours a day and transmitted as it is made. This Earth orbit (GEO). A typical size for these seductive concept becomes more attractive if the rectangularly-shaped satellites is 5 by 10 km. costs of all of the required technologies to This large surface is almost entirely covered assemble and maintain it are small compared to with solar cells. As the energy is produced, competing terrestrial power sources. it is transmitted to a ground station with a microwave beam. The transmitting antenna Many past studies of space power have made diameter is 1 km. The frequency of the both realistic and optimistic assumptions of the microwave transmission would be 2.45 costs of the power generation, of maintenance, GHz. On the ground, a receiving antenna, or and of transportation technologies. In the most rectenna, would intercept the beam and realistic and near-term cases, space power can ground processing stations would convert the provide specific benefits for a restricted set of energy into usable power for the main users in space and on the ground. In its most electricity grid. While ambitious,thisideafor generatingpower andinternationalagreements.This for Earthisexpensive.Theinitial investment interdisciplinaryperspectiveis wherethe costsbasedon theNASA/DOE studyestimated IntemationalSpaceUniversity(ISU) can theinvestmentcostsoverthefirst 30 yearsto be playanimportanteducationalandtechnical morethan2 trillion dollars(FY 1992dollars, role. Ref. 1). Thepaybackfor thesystembegan20 to 40 yearsafterthefirst operationalpowersatellite Wha_ Is the International launch. Evenwith aninternationalprogram,it is Space University2 unclearthat SpaceSolarPowerwill beattractive in alargescaleapplication. ISU therefore The ISU is a major venue for students from embarkedon thetaskof finding amorecost- all over the world to discuss and assess effectivemethodorpathto developthe future space missions and applications. Not technologiesfor SSPP. only does ISU provide a fertile ground for the review of space projects, but it allows As partof the199210-weekInternationalSpace persons from all over the world to meet and UniversitySummerSession,severalalternative attempt to open the floodgates of international spacesolarpowersystemswerestudied.Space communication between space enthusiasts. powersystemsfor ground-basedandspace- basedpowerusagewereenvisioned.During this Each summer since 1988, ISU has study,manyof theassumptionsof pastanalyses sponsored a 10-week session in a different werereviewedandcritiqued. Thelargedrivers city around the world. Cambridge, in costwerereviewedanda seriesof Massachusetts (USA), Strasbourg (FRA), demonstrationprojectswereconceivedto show Toronto (CAN), Toulouse (FRA), and thepossiblebenefitsof spacepowerfor ground- Kitakyushu (JPN) have been past ISU sites. baseduse.Thecostreviewhelpedfocusthe These sessions are a very intense time of directionof our studygroupsandallowedusto education and commitment to a design list importantdirectionsfor futurestudies.The project. To complement the stresses of the demonstrationprojectsshowedthatthecostsof academic workload, there are many cultural spacesystemsarenotlow. Futuresystemsmust and social activities to promote a cooperative establishnewparadigmsin spaceflight to reduce atmosphere amongst the students and the thesecostsif spacepoweris to becomeaviable faculty. In Kitakyushu, the ISU community energyalternative. was even invited to perform traditional Japanese dances in a local festival. Thecostof spaceaccesswasoneof themajor costfactorsin thedevelopmentandoperationsof The summer sessions will ultimately be spacepowersystems.Spacetransportationcosts complemented with a permanent