EDWARDS AIR FORCE BASE, Calif -- The Scaled Composites, Incorporated. White Knight mothership air-dropped the X-37 at about 37,000 feet, and the Unmanned Aerial Vehicle made an autonomous flight to Runway 22 where it landed safely but ran off the end of the runway. The X-37 originated as a National Aeronautics and Space Administration demonstrator for the Future X orbital test and reentry research program in the 1990s. It was since revived as a Defense Advanced Research Projects Agency-Boeing Approach and Landing Test Vehicle.
The Department of the Air Force Rapid Capabilities Office is leading the Defense Department’s Orbital Test Vehicle initiative, by direction of the under secretary of defense for acquisition, technology and logistics and the secretary of the Air Force. The Air Force OTV effort uses extensive contractor and government investments in the X-37 program by the Air Force, NASA and the Defense Advanced Research Projects Agency to continue full-scale development and on-orbit testing of a long-duration, reusable space vehicle.
NASA’s original X-37 program began in 1999 and was transferred to DARPA in 2004. NASA envisioned building two vehicles, an Approach and Landing Test Vehicle, or ALTV, and an Orbital Vehicle. DARPA completed the ALTV portion of the X-37 program in 2006, executing a series of captive carry and free flight tests. DARPA successfully validated the flight dynamics and extended the flight envelope beyond the low speed/low altitude tests previously conducted by NASA on the X-40A, a sub-scale version of the X-37 developed by Air Force Research Labs. NASA’s X-37 Orbital Vehicle was never built, but it's design was the starting point for the Air Force’s X-37B Orbital Test Vehicle program.
The Air Force has successfully flown five X-37B missions, OTV-1 through OTV-5. All five missions launched from Cape Canaveral Air Force Station, Fla., beginning with its first launch on April 22, 2010. OTV-1 through OTV-3 all landed at Vandenberg Air Force Base, Calif., while OTV-4 and OTV-5 landed at Kennedy Space Center, Fla. Through five completed missions, the X-37B has spent a total of 2,865 days on orbit, successfully checking out the X-37B’s reusable flight, reentry and landing technologies as well as operating experiments to benefit the national space community. The current mission, OTV-6, was launched on May 17, 2020 from Cape Canaveral on an Atlas V.