SPS Feasability Study SD76SA0239-2

modules, landing site cargo handling, free-flyer beam machines, wiring, solar cell blankets, and mirror storage (i.e., a small-scale version of all elements defined in the assembly process) probably will be required. The antenna main- tenenance requirements are shown in Figure 3.8-1. Elements not shown are crew habitats, electronic spares storage, and other elements needed for the repair of high-voltage, high-current power transmission. The main 57-meter signal generating source and multi-lobe transmitter, not described in the assembly process, is shown on Figure 3.8-1. The signal source is mounted on a curved track located approximately 250 meters from the antenna, with the trunnion pivot centerline as the center of curvature. As the antenna is pivoted on the trunnion, the signal source moves along the track that maintains a constant perpendicular distance from the center of the antenna two-meter dish receiver network. A set of cable crane-way complexes are left on each wing of the SPS upper longerons. These facilities, though shown near the antenna, may remain at any location along the structure and will not produce detrimental shadowing of the solar cell blankets. In general, one additional cable craneway complex may remain near the base complex located on the last SPS frame structure. In addition, the upper three main longerons may overhang the last frame one or two 50-meter longeron bays to provide access to the facility warehousing at a safe distance from the solar cell blankets. Figure 3.8-1. Microwave Antenna Maintenance Concept