the cargo to the construction and fabrication sites of the SPS. All equipment and facilities, except transportation equipment, will remain attached to the SPS throughout construction. Construction equipment and facilities, including the construction facility power sources, will remain in LEO after completing an SPS and will be utilized for subsequent SPS assembly. One SPS will be delivered to GEO each year for 30 years. Figure 9-7 shows a candidate schedule for assembly and delivery of three consecutive SPS's. Allowing 1 month for construction facility refurbishment leaves 330 days for accomplishing assembly. The rates of assembly required to meet this schedule imply that as much ground fabrication be done as is consistent with high density HLLV cargos and that the remainder be fabricated and assembled with automatic equipment in orbit. Technology development should begin very soon to develop cognitive robots for automatic assembly and automatic maintenance. 9.3.2 C ONSTRUCTION A discussion of the construction of a photovoltaic SPS is presented here. Assembly would begin with construction of the center portion of the power conduction mast which will be the backbone of the SPS. Fabrication of the arrays and rotary joint will begin after approximately 40 days. The arrays will be assembled around a clam shell type jig (Fig. 9-8). Beams are assembled around one-half of the jig which rotates the structure into position to be attached to the existing structure. While this half is being attached and outfitted with blanket packages and reflector packages, the other half of the jig rotates out of the previous cell and begins assembly of the next cell. An 8 h jig cycle can assemble the 800 array cells and the 100 dielectric cells in approximately 300 days. Guide wires for later deployment of reflectors and blankets are installed as shown in Figure 9-9. Blankets are in folded packages; reflectors are in rolls and installed at opposite ends to avoid interference. Beam fabrication could be performed either inside the jig or at some central site and transported to the jig. Rotary joint elements are likely to be somewhat unique, lacking a repetitive type of operation and requiring more man involvement either directly or via teleoperators. Antenna fabrication can begin after some progress has been achieved on the rotary joint. Figure 9-10 shows a top level allocation of the 330 days allowed for construction and indicates the quantity of material involved in each task. Assembly of the antenna structure would be similar to the array assembly in that beams would be assembled around a jig or scaffolding. Alignment tolerances would probably prevent use of a flip-flop jig, and jig movement by smooth linear motion probably would be preferred. Antenna structural beams and subarray units should be fabricated or constructed at a central site of the
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