NASA studied this General Dynamics/Convair concept for a fully reusable space transportation system early in the Shuttle research effort of 1969-1972. This two-stage system featured three piloted fly-back vehicles, an orbiter sandwiched between two boosters, all using liquid propellants. All would ignite together for lift-off, and the boosters would detach and fly to land when their fuel was consumed while the orbiter continued on to space. All three vehicles had snap-out wings and jet engines for return flight. NASA transferred a variety of concept models to the Museum after settling on the final Space Shuttle design.
This object is on display in James S. McDonnell Space Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA.