Fig. 1. Satellite power system concept. 2). The total DOE program includes system definition (of which this study is a part); socioeconomic studies; environmental, health, and safety studies; and a comparative assessment of SPS with other candidate energy concepts. This is the second year of contract effort which is being conducted for NASA Marshall Space Flight Center. One of the major results of the first year of effort was data used by NASA to define two reference concepts which are being used by DOE for their evaluation. The second year's effort concentrated on a more detailed definition of the reference concept, trades relative to the reference concept, conceptual approaches to a solidstate microwave transmission alternative to the reference concept, and further definition of the program. This paper summarizes that effort. SPS CONCEPT EVOLUTION The matrix of concepts selected for analyses and trade studies during initial SPS system studies is shown in Fig. 2. Both silicon and GaAs solar arrays were considered for a concentration-ratio-of-1 solar photovoltaic concept. At higher concentration ratios, only GaAs arrays were considered because silicon cell performance drops sharply at the higher cell operating temperatures that occur when concentrators are used. Two basic thermal cycles, Brayton and Rankine, were considered for solar thermal concepts. An overall evaluation of these concepts was performed and, as a result, the satellite concepts shown in Fig. 3 were considered to be viable candidates. Nuclear concepts were rejected, not only because of noncompetitive cost, but also because
RkJQdWJsaXNoZXIy MTU5NjU0Mg==