SPS Feasability Study SD76SA0239-2

effort conducted to date with respect to the total program structure has been that accomplished by MSFC. Figure 5.1-1 shows the basic structure established for the programmatic assessment that was conducted. Although this structure generally conforms to the MSFC concept, there are significant differences in two major areas: (1) the transportation concept and (2) the incorporation of SPS ground receiving station as an integral element of ground operations. The breakdown structure provides the structure for the program development schedule (Figure 5.1-2). The four major program elements shown on the schedule conform to the structure except for the ground support system, for which only the rectenna or receiving station is shown. Excluded from the schedule is any representation of the supporting technology development that will be required for SPS. For general planning purposes it can be assumed that technology development could start as early as 1978. The schedule shown is but one example of a logical evolution from current technology and currently visualized programs to an SPS IOC in 1995. Assessment of current space program planning leads to two significant conclusions: 1. There is a mutual reinforcement between current Space Station and Space Transportation System planning and their potential evolution into the construction base for SPS. 2. The evolution of transportation vehicles for future space requirements is consistent with SPS requirements and program phasing for 1995 IOC. Figure 5.1-2. SPS Program Development