Solar power satellite

The solar power satellite (SPS) concept, under evaluation by NASA since 1974, is discussed. A typical system providing a total of 10,000 MW of electrical power to the ground receiving stations is considered. Energy conversion systems, including the photovoltaic device category using single-crystal silicon cells, are taken into account, as are the 2.45-GHz microwave power-transmission link and the ground receiver (or rectenna). Concepts involving space construction of the satellite's large structures (5 x 25 km) are described, noting that a process similar to the familiar roll-forming of light sheet metal parts has been adapted to the space environment. Transportation vehicles are discussed, including the Space Shuttle planned to reach 60 flights per year by the mid 1980's. Electrical power forecasts and advanced systems cost projections are analyzed, together with a description of costs estimates. The indirect economics of energy research and development, and the present NASA/DOE SPS program are noted.