SPS Feasability Study SD76SA0239-2

1. INTRODUCTION Studies conducted by government agencies and by industry have clearly delineated the urgency for developing new energy-producing sources to meet the ever-increasing future demands for electrical power. The controversies surrounding high oil prices and limited reserves, atmospheric pollution, and nuclear safety - whether justified or not - have served to bring the energy crisis to a national awareness. It is logical, therefore, that attention is turning to the potentiality of tapping the unlimited resources of the sun. Many ingenious approaches have been postulated and some are technogically feasible. Most, however, cannot meet reasonable economic criteria as evidenced by the current lack of large capital investments for operational systems. For the past few years, the aerospace industry, under the guidance and funding of joint NASA/ERDA teams, has been investigating the practicality of intercepting sunlight in space, converting it to electricity, and - via microwaves - transmitting it to earth for subsequent reconversion and distribution over typical earth-based transmission lines. Results from these preliminary studies are encouraging. They show that with proper emphasis, judicious planning, and adequate funding, the projected mid-1980's technology would suffice to develop such systems that are both technically feasible and economically viable. Historically, development of new space systems from a given technology base takes from five to fifteen years; therefore, it does not appear unrealistic to estimate an initial operational capability (IOC) date for the satellite power system (SPS) in the mid-1990's. The level of contribution SPS could make in meeting the projected national energy demands will ultimately depend on its degree of cost competitiveness and other key criteria. A reasonable goal has been established for SPS to supply about 25 percent of the projected electrical energy demands in the year 2025. In terms of energy production capacity, this converts to a requirement of about 600 gigawatts. In general, these technology levels, IOC dates, and power generation requirements constitute the broad NASA/ERDA guidelines for this and other recent studies. 1.1 STUDY APPROACH The Space Division of Rockwell International proposed to conduct an extensive four-month technical effort to study the technical feasibility and economic viability of SPS based on an end-to-end analysis of "reference" designs and operational concepts. A functional task overview of this study is depicted in Figure 1.1-1. The first task defined a satellite and each of its systems in sufficient detail to develop appropriate design, performance, and cost data. The second task required analyses of on-orbit operations in order to develop assembly schedules, define required crew complements, design construction base concepts, and to provide a basis for costing these operations and hardware. Having defined the on-orbit satellite system and described the processes and equipment needed for its assembly, the third task required definition of the transportation systems, traffic models, and costs associated with placing in orbit all of the SPS hardware elements and the equipment and