NASA-LaRC

Slide 51 of 125

In early 1985, the Langley Research Center was asked by NASA Headquarters to initiate preliminary conceptual studies of a next-generation launch system called "Shuttle II" for AD 2005 and beyond. Unlike the original one-size-fits-all Space Shuttle or the 1981-84 NASA/Langley Future Space Transportation System, the new system probably would consist of different vehicles -- manned and unmanned, large and small, expendable and reusable. One such subcomponent was the "Shuttle II" which was envisioned as a fully reusable low-cost piloted vehicle capable of transporting 9,072kg to Space Station Freedom in a 4.5 x 9m payload bay or 4,553kg to a 277km sunsynchronous orbit. NASA also wanted a more robust system capable of safely flying quick-sortie missions (<3 days duration) every two weeks with a minimum of maintenance and checkout between flights. The important missions were personnel transport, in-orbit servicing & repair, and return of high-valued commercial products from orbiting space platforms. In other words, missions where a "low dollars per flight" approach was regarded as more important than "low dollars per kilogram"; the latter requirement (low cost transportation of unmanned military & civilian heavy-lift payloads) was to be served by the Advanced Launch System.

Advanced Launch Vehicle (Rockwell International concept)

Different "Shuttle II" concepts were investigated but the initially most promising concept appeared to be a VTHL TSTO with parallel staging at Mach 3. This was a very similar concept as the 1981-84 FSTS baseline vehicle, albeit much smaller. CH4, LOX & LH2 propellants would have been used. VTHL SSTO also appeared feasible with modest advances in performance technologies. The Shuttle II's operational life would be 15 years, or 400 flights per vehicle and the Langley Research Center made a conscious effort to avoid the Space Shuttle's problems when designing the new system. For example, no toxic hypergolic propellants would be used to reduce the maintenance cost, and the rocket engines and thermal protection system would be more durable than the original Shuttle's.

For SSTOs, a "bimese" twin configuration was proposed for heavy-lift missions, while relatively small solid or liquid augmentation boosters would greatly increase the SSTO payload capability, e.g. to polar orbit. Tripropellant VTHL TSTO with Mach 3 staging was regarded as more low-risk, but SSTO would clearly be more attractive if advanced NASP-level technologies could reduce its dry mass by 60%. It would then have superior inclination, altitude & operational performance to that of the TSTO.

Payload capability: 9,072kg to a 28.5 degree 400km orbit;5,443kg to a 277km sunsynchronous orbit.

Payload bay: 9m x 4.5m diameter.

Stage 1 : 6 x Space Transportation Main Engine. Liftoff thrust: 6,675 KN. Isp: . Gross Mass: 395,532kg. Empty Mass: 38,555kg. Length: 32.3m. Width: . Propellants: LOX/methane.

Stage 2 : 5 x modified SSME. Liftoff thrust: 6,675 KN. Isp: . Gross Mass: 527,981kg. Empty Mass: 82,100kg. Length: 42.5m. Span:33.5m. Propellants: LOX/LH2.

”Shuttle II: A Look Ahead” -- Talay, AAS Science & Technology 1987/vol.69/p.185

”Shuttle II Progress Report” -- Talay, Space Congress Proc. (24th) 1987/7-1

"Orbital Express" -- Reichhardt, Space World 1987/June/p.27