9.27 rotating tube, and launched in the desired direction to provide thrust. Launching 10 gram pellets at the rate of 80 per second, it is shown in the reference (9.11) that the theoretical performance gained is a thrust of 723 pounds at a specific impulse of 405 seconds, with a launching arm weight of 19,000 pounds and a power requirement of 6560 kilowatts (9.10). The mission of the ILTV consists of catching and transporting the lunar mass from L2 to LS. The proposed mission profile consists of one ILTV remaining on station for three months, and then moving off under the power of its rotary pellet launchers to rendezvous with the colony construction site at LS. The total trip time is also estimated to be on the close order of three months, so that only two ILTV's are required (9.11). Crawley estimated the total airframe mass to be 10,000 kilograms (9.12). The mass of two rotary pellet launchers, at 8636 kilograms each, is 17,272 kilograms, and the mass of the· necessary power generating equipment for 13,200 kilowatts, calculated at the rate assumed previously in this report for space power systems, 10 kg/kw, is found to be 132,000 kilograms. The total mass of a single interlibration point transfer vehicle is then 160,000 kilograms. IX.2: TRANSPORTATION COSTING RATIONALE Since the basic devices used for transportation have now been determined, they can be costed to determine transportation costs in relation to overall program cost. Since there is little rationale existing for directly costing transportation systems from preliminary designs, the systems used in this project must be costed in relation to similar, existing systems with known costs. The launch costs of the space shuttle were determined by NASA in their advance mission planning to be $10.5 million per flight, in constant 1971 dollars. Inflation rates over the past few years have forced a reassessment of this launch cost, which is currently estimated by NASA at $19 million per flight, in constant 1977 dollars (9.13). The six year separation of these two figures represents an
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