A. INTRODUCTION Energy and material resources beyond the Earth's biosphere hold great promise for improving the quality of life on this planet. Ultimately they may also enable humanity to transcend the limitations and constraints of the Earth, by establishing human colonies in space. Before space industrialization becomes a reality, however, a number of critical research projects must be carried out. The Space Studies Institute, through private funding, sponsors such research, of which this Solar Power Satellite (SPS) study is a part. The purpose of this study is to identify the most commercially feasible way to construct a Solar Power Satellite using materials obtained from the Moon. It is anticipated that if this study yields promising results, more extensive studies may be funded. B. OBJECTIVES The principal objective of this solicitation is to identify a preferred commercially feasible way to build an SPS using lunar materials, thus eliminating as far as possible the need for lifting materials from the Earth. The focus of the effort is on SPS design concepts that effectively utilize engineering materials derivable from lunar resources to maximize commercial feasibility. Most of the government-funded SPS studies in the 1976-1981 time period were constrained to consider only launch from Earth. A secondary objective of this study is to identify new ideas and alternatives that are possible when this constraint is removed.