INTEGRATED SPACE OPERATIONS OVERVIEW Gordon R. Woodcock Boeing Aerospace Co. Space delivery, construction and maintenance of solar power satellites will require an integrated network of space operations including several transportation systems as well as construction and operations bases. The interrelationships among the various operations set the flight rate and capacity requirements on them and hence must be taken into account in determination of the space operations costs for SPS. Figure 1 illustrates the elements of the integrated operations. Launch vehicles deliver crews and material to low Earth orbit (LEO). Heavy lift vehicles carry cargo and propellant while personnel launch vehicles (modified Space Shuttles) carry crews to and from orbit. Their deliveries are made to a base in low Earth orbit. This base is a staging area for crews and cargo and also serves as an assembly base for the electric orbit transfer vehicles (EOTV's) that carry cargo to and from the geosynchronous orbit (GEO) base. At the LEO base cargo and propellant pallets are removed from HLLV's, stored as necessary, and transferred to EOTV's. Each EOTV can carry ten HLLV payloads; a fleet of about 25 EOTV's shuttle payloads to GEO and return empty shipping containers. A typical EOTV round trip takes 8 to 9 months. Personnel and priority supplies are delivered to the GEO base by a personnel orbit transfer vehicle (POTV). Chemically-propelled, this type of vehicle sacrifices efficiency for speed. It can make the trip from LEO to GEO in less than a day and return in a similar time. The POTV carries 80 passengers and a few tons of cargo. The passenger accommodations are similar in appearance to those of a jet airliner as shown in Figure 2. Figure 3 shows the POTV passenger module joined to its propulsion stage. Operating satellites will require periodic maintenance. The reference scenario calls for a visit to each SPS every six months to remove and replace defective hardware and replenish consumables. The GEO base serves as a headquarters and staging area for maintenance operations as well as for construction of satellites. The maintenance sortie vehicle system includes a crew habitat for 80 people, and personnel OTV's for transport of the maintenance crew and material from the GEO base to the SPS's needing maintenance. On a 90-day sortie, one vehicle can visit and service 20 SPS's. Remove, replace and replenish operations at each satellite are estimated to require 4 to 5 days, aided by semi-automated remove and replace equipment permanently installed on each satellite.
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