How long would it all take? Is this a next-century solution to a this-century problem? Boeing’s preliminary studies have indicated that an orderly three-phase development program (see fig. 7) could place the first operating powersat in service in approximately 15 years. This prediction is entirely consistent with the historical fact that significant advances in aerospace technology require from 12 to 15 years to reach fruition.

The first phase is a detailed engineering analysis and design-to-cost optimization study. Supported by tests and experiments in critical areas, this phase would yield selection of most design features, and higher confidence in system economics and would provide firm direction and guidelines to the succeeding advanced development phase.

The second or advanced development phase would develop and prove out, by subscale flight demonstration, all the critical elements and features of the entire system except the space freighter. Flight experiments and pilot-plant assembly and operation could be a principal mission for the space shuttle in the early- to mid-1980’s.

The third phase or full-scale development program would begin with design definition and long-lead development of the space freighter. High confidence in its performance, cost, and operational characteristics would be available when results from the advanced development program merited a final decision to proceed with the entire powersat system. The development phase includes design and construction of the ground and space facilities required to deploy one 10 000-megawatt satellite per year.

Forecasts indicate that by the 1990’s the United States will need to add between 30 000 and 70 000 megawatts of new generating capacity per year (see fig. 8). The Boeing powersat economic analyses conservatively assumed capture of about one-fifth of this market. A greater powersat addition rate could be implemented if needed.