SPS Feasability Study SD76SA0239-2

5.3 TECHNOLOGY ADVANCEMENT Each major subsystem area of the SPS was reviewed to identify areas in which present technology was inadequate to meet the requirements of SPS. Technology assessments were not restricted to requirements of the reference configuration. Rather, a more general view of SPS requirements, encompassing various vehicle configurations, was used. It was found that most of the technology advancement requirements are relatively independent of the particular configuration so that the requirements discussed here are generally applicable. As a ground rule for planning purposes, the operational SPS was assumed to be based on the level of technology available in 1985. Schedules to develop the necessary capability were prepared for each of the technology areas. To the level of detail possible in the present contract, the resulting schedules showed at least some level of effort was necessary almost continuously in each technology area between now and 1985 to meet requisite technology requirements. The level and type of effort over the period varied as such items as Space Shuttle and Space Station became available. Future efforts in this area should concentrate on defining programs, goals, and levels of effort in greater detail to meet SPS requirements. The present assessments of technology advancement requirements are summarized in Table 5.3-1. Each technology requirement was analyzed to determine whether it was critical for program success or greatly enhanced the probability of program success. These estimates are listed in the second column of the table. Most items are identified as critical. Present capabilities are defined to provide a reference point for the amount of technology advancement required in each area. Finally, the required level of technology is estimated for SPS applications. Each technology area is discussed in the following paragraphs. 5.3.1 Fabrication/Assembly Technology Item — Fabrication/Assembly Criticality — Critical to program success SPS is the first program that requires in-orbit assembly of large complex vehicles. The necessary fabrication and assembly techniques and equipment must exist to build the SPS flight vehicle. Present Capability: This entire technology area is being discussed as one item because of the lack of present capability in each of the specific areas. No existing satellite has required significant in-orbit assembly. The closest thing to it is deployable antenna, arrays, and booms and the repairs performed on Skylab. In each of these cases, the fabrication and assembly was performed on the ground prior to flight. Some earth based structures require operations and equipment that may provide useful insights into requirements. However, none of these are space qualified. An example is roll forming equipment that can provide a starting point for designing a beam machine. Engineering studies have provided an initial assessment of requirements and approaches to this area.