This model depicts the final design from North American Rockwell that emerged from Space Shuttle studies in 1969-1972. The partially reusable space transportation system included a reusable orbiter attached to a disposable external propellant tank and two solid rocket boosters that were retrieved and refurbished for reuse. The orbiter had delta wings for return-to-landing maneuverability but did not have engines for atmospheric flight and thus returned as a glider. Rockwell won the competition to become the Shuttle prime contractor, but other companies that participated in the design studies were selected to provide some of the elements. Rockwell International gave this model to the Museum.