NASA Lunar Energy Enterprise Case Study (1989) This task force examined the major options for the utilisation of extra-terrestrial power. It outlined the major developments in key space power-related technologies and evaluated the significance of these developments in relation to space power as an alternative energy option for use on Earth and as a potential stimulus for space infrastructure developments. It also examined possible usage of extraterrestrial resources. They also studied Solar power bases constructed on the moon to supply the majority of the power needed on Earth. _____ , Report of NASA Lunar Energy Enterprise Case Study Task Force, NASA Technical Memorandum 101652,1989 Earth to Space Transmission Concepts (1989) Several concepts for large scale Earth to Space power beaming have been proposed, including large industrial parks powered by a system of equitorial earth-based transmitters. A variation on this theme is to use this power to drive electrical propulsion on a large platform to be used for payload transfer between low earth and geosynchronous orbit. Brown, W., History and Status of Beamed Power Techn ology and Applications at 2.45 GHz, Second Beamed Power Space Workshop, p. 181, NASA, 1989 Solar power satellites built of lunar materials (1985/1989). Commissioned by the Space Studies Institute from Space Research Associates. The purpose of the report was to consider the extent of possible uses of lunar materials in space power satellites. All relevant technologies were considered as in the NASA study, but with the emphasis on optimising the design for use of lunar materials. The 1985 study considered transportation of materials from the moon to geostationary orbit to be a factor of 50 less expensive than from Earth and all reasonably abundant lunar materials were considered available for use. The conclusion was that 99% of a space power satellite could be constructed from lunar materials. In 1989 a follow-up study was commissioned. This time there were restrictions placed on the materials available for use. Only those which could simply be extracted were considered. When Space Shuttle external tanks, glasses and glass-glass composites were allowed, the study consluded that 64.9% of a space power satellite could be lunar in origin, with a 55.1% cost reduction when compared to the NASA/DOE baseline study. Considering availability of iron and oxygen in addition, 91.7% lunar construction was reported, with a 69.8% cost reduction. In this case the price of using GaAs solar photovoltaics with concentrators became comparable to planar silicon structures. _____, Solar power satellite built of lunar resources, Space Research Associates, 1985 _____, Near-term non-terrestrial materials usage in solar power satellites, Space Research Associates, 1989 SPS 2000 This design model has been proposed by the ISAS Space Power Satellite Working Group to generate a clear image of realistic space power systems. They selected an equational circular low earth orbit for such systems because of projected launch system availability before 2000. The satellite consists of a prism shaped structure stabilised by a gravity gradient. It collects energy using photovoltaics and aims to transmit 10MW at 2.45GHz to Earth. Ilie study is intended to consider not only the technical aspects of space power but also the environmental aspects of its implementation. Nagatomo, N. & Kiyohiko, I., An Evolutionary satellite power system for international demonstration in developing nations, SPS ‘91. Power from Space, Soci6t6 des Ingdnieiurs at Scientifiques de France, p. 356,1991 Project SELENE (Space Laser Electric Energy) Systems studies and technology development work towards creation of a 10m segmented telescope to send 10MW from FEL (free electron laser) in the micrometer range to spacecraft. The power would be collected with conventional solar cell technology. The study also examines methods for optimising solar cell response for the beam and improvements in FEL technology.
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