The Martin Marietta Spacemaster was a proposed design for the Space Shuttle. The Spacemaster was a two-stage, reusable space transportation system. It featured a delta-wing orbiter and a twin-fuselage booster craft. The orbiter would sit in a recess in the booster during launch and ascent.
The liquid-propellant booster would carry the orbiter to a set altitude, then detach and be piloted back to land. After separation, the orbiter would ignite its own engines to reach orbit. The Spacemaster was proposed in 1967. NASA did not order any Spacemasters, but it did order the Space Shuttle’s external fuel tanks from Martin-Marietta.
Martin Marietta is now part of Lockheed Martin.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.