An experimental aircraft that was a predecessor to the space shuttle. It was produced by NASA and the Douglas Aircraft Company (later McDonnell Douglas). Without a pilot, the rocket-propelled DC-XA took off vertically, flew under remote control, and landed as a normal aircraft. The 13-m DC-XA made three successful test flights in 1966 at the White Sands Missile Range, New Mexico, but on the fourth flight a landing gear failed to deploy and it crashed on the runway. NASA then moved on to other prototypes in its X-series.