The four transportation modes selected for Task 1 represent the near term Space Transportation System capabilities. A Transtage was selected, both in an expendable and reusable version, as being most representative of the performance of the Interim Upper Stage (IUS). A Full Capability Cryo Tug was used to represent the STS performance capability in the 1984 time frame. The fourth option, Shuttle/Low Altitude Assembly, was introduced into the matrix to determine the impact of assembly altitude on overall system selection. Antenna geometry options include a rectangular grid and a radial spoke structural layout. Both these structural arrangements are acceptable in terms of available layouts for the power distribution system. Antenna diameters between 0.7 to 1.4 km were included in the design matrix after Raytheon’s preliminary results indicated that optimum system performance would fall within these bounds. The Task 1 study logic for control analysis and thermal structural analysis and cost parametrics are outlined in Fig. 1-2. The output of the three principal tasks are recommendations for a limited number of control system, structural and flight operations options for detailed concept definition in Task 2. The limited number of design options recommended in Task 1 were evaluated in greater detail in Task 2, Concept Definition, using the study logic shown in Fig. 1-3. Information generated during Concept Definition will permit Raytheon to carry out technical and economic evaluation leading to selection of a single configuration to be the basis for ground demonstration test. Flight plans were generated for assembly of the SSPS at a low altitude which is within the performance range of the Shuttle with integral OMS, and at an altitude above the Van Allen belts. Traffic rates and fleet size requirements were established for a one and two year assembly period. Packaging densities of SSPS components were considered in establishing the method of assembly using manipulative devices, maneuvering units, and EVA. Assumptions concerning degree of human skills are outlined as well as the potential capability of support ancillary equipment. Sensitivity analysis of various levels of ground prefabrication compared to corresponding levels of orbital assembly was performed to determine the most cost effective approach to structural assembly.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==