A large “mothership,” closely resembling the U.S. Air Force’s historic XB-70 supersonic bomber, carries the orbital component conformally under its fuselage, accelerating to supersonic speeds at high altitude before dropping the spaceplane. The orbiter’s engines fire and boost the vehicle into space. If mission requirements dictate, the spaceplane can either reach low Earth orbit or remain suborbital. —Two-Stage-to-Orbit ‘Blackstar’ System Shelved at Groom Lake?