Martin Marietta Spacemaster
| Function | Manned Re-usable orbital launch vehicle |
|---|---|
| Manufacturer | Martin Marietta |
| Country of origin | United States |
| Size | |
| Height | 128 m (419 ft) |
| Diameter | 8.0 m (26.2 ft) |
| Mass | 3,500,000 lb (1,590,000 kg) |
| Stages | 2 |
| Capacity | |
| Payload to LEO | 50,000 lb (22,700 kg) |
| Launch history | |
| Status | Cancelled |
| Launch sites | LC-39 Kennedy Space Center |
| Total launches | 0 |
| First stage | |
| Engines | 14 Rocketdyne SSME |
| Thrust | 28,080 kN (6,313,000 lbf) |
| Burn time | 155 seconds |
| Fuel | LH2/LOX |
| Second stage | |
| Engines | 2 Rocketdyne SSME |
| Thrust | 4,549 kN (1,022,700 lbf) |
| Burn time | 276 seconds |
| Fuel | LH2/LOX |
The Martin Marietta Spacemaster was a proposed configuration for what became the Space Shuttle, which featured an X-24-derived orbiter, and an unusual “catamaran style” booster stage. During launch and ascent, the orbiter would be located in a recess in the booster. The booster's 14 engines would be located in clusters of seven, at the bottom of both halves of the booster. Unlike the final design for the Space Shuttle, the Spacemaster would lack an external tank, and the boosters would be joined, by means of connecting struts which would also serve as the mounting for the orbiter.
The concept was evaluated in 1967, but was rejected. Martin Marietta went on to produce the Space Shuttle external tank (ET) for the final STS Space Shuttle design (by Lockheed Martin after a merger with Lockheed).