NASA studied this Lockheed Martin concept for a partially reusable space transportation system during the Shuttle research effort in 1969-1971. It featured a delta-wing orbiter vehicle flanked by two large external fuel tanks. It was called a stage-and-a-half vehicle because the orbiter would launch itself without a booster and fly all the way to orbit using its own rocket engines fed by the external fuel tanks (the half-stage), which would be jettisoned when empty. The reusable orbiter had retractable wings and air-breathing jet engines that deployed after reentry, enabling it to fly like an airplane to landing. NASA transferred a variety of concept models to the Museum after settling on the final Space Shuttle design.
Transferred from National Aeronautics and Space Administration.