NASA-LaRC

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Langley single-stage-to-orbit launch

The FSTS study concluded that TSTO+advanced technologies produce a much smaller vehicle than a single-stage-to-orbit system. Operational considerations and minimum weight requirements forced the designers to settle for a smaller external, encapsulated payload pod rather than a Shuttle-type internal cargo bay. Small wingtips on the orbiter work better at supersonic speeds and weigh less than a traditional vertical tail. Parallel staging+propellant crossfeed were introduced to reduce the length of the TSTO, simplify the mating process, reduce axial loads on the booster and reduce the total number of engines. The main drawback is significant lateral movement of CG as the booster's tanks are depleted, so the engines require a large gimbal range. Staging at Mach 3 works best since the booster needs no thermal protection or auxiliary propulsion (which otherwise would increase the dry mass by 9%) to return to the launch site.

Payload capability: 68,000kg to a 31 degree 486km orbit; Payload bay: 27m x 6m diameter.

Stage 1 : 5 x 2,830KN thrust hydrocarbon engines. Liftoff thrust: 14,150 KN. Isp: 355s [vac.]. Gross Mass: 975,223kg. Empty Mass: 76,657kg. Length: . Width: . Propellants: LOX/kerosene.

Stage 2 : 7 x modified SSME. Liftoff thrust: 14,000 KN. Isp:465s [vac.] . Gross Mass: 1,246,000kg. Empty Mass: 130,181kg. Length: 57.3m. Span:45.4m. Propellants: LOX/LH2.

"Future Space Shuttle Design Under Study" -- Space World, 1984/January/p.18