McDONNELL-DOUGLAS & MARTIN MARTIETTA PHASE B SHUTTLE [1971]
Notes:
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NASA awarded the other shuttle Phase-B contract to McDonnell-Douglas and General Dynamics. The contractors reported back on June 30, 1971. The General Dynamics booster was derived from an alternative “Spacemaster” design. Its landing jet engines were installed inside the forward canrd wing to improve the center of gravity, to compensate for the huge mass of the ascent propulsion system which consisted of thirteen Space Shuttle Main Engines. The high-mounted aft wing with wing tips was chosen to provide the least interference with the orbiter at launch while still producing adequate stability for the booster.
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Unlike North American Rockwell, McDAC settled for a metallic thermal protection system on the shuttle orbiter. Titanium, nickel and columbium materials would have been used. In most other respects, the McDAC and NAR Phase B orbiters wre quite similar. Both featured a large delta wing plus single vertical stabilizer fin, an 18.3 * 4.57-meter cargo bay, two Space Shuttle Main Engines for propulsion and RL-10s for maneuvering in space.
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McDonnell-Douglas shuttle orbiter with sortie module. NASA planned a series of pressurized and unpressurized experiment modules for the space station and space shuttle. They would be used for carrying space station logistics, as free-flying experiment carriers and other purposes. As the space station was postponed, the experiment module gradually evolved into a “sortie lab” for the shuttle, essentially transforming it into a mini-space station for flights lasting up to 30 days. General Dynamics received a contract to study space station experiment modules in August 1969 which eventually morphed into a shuttle “Research and Applications Module” (RAM). The General Dynamics RAM contract was extended in April 1971 but NASA was unable to afford the cost in the end. The “Spacelab” project was finally farmed out to the European Space Research Organization in June 1972.
NASA's Phase B Shuttle flight plan called for 445 missions over ten years. 15.73% of the flights would involve space station assembly & logistics, 42.25% would be dedicated to deployment of NASA satellites and space probes and another 34.61% would be reserved for the military. The remaining 7.41% would be dedicated to OTVs, i.e. “space tugs” transporting cargo to higher orbits.
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