SpaceShipOne is a spaceplane that completed the first privately funded human spaceflight on June 21, 2004. It was developed by Scaled Composites.
SpaceShipOne was an experimental air-launched suborbital spaceplane that used a hybrid rocket motor. The design featured a unique "feathering" reentry system where the rear half of the wing and the twin tail booms folded upward along a hinge running the length of the wing; this increased drag while remaining stable.
The achievements of SpaceShipOne are more comparable to the X-15 than orbiting spacecraft like the Space Shuttle. Accelerating a spacecraft to orbital speed requires more than 60 times as much energy as lifting it to 100 km.
SpaceShipOne was developed by Scaled Composites, Burt Rutan's aviation company, in their Tier One program, without government funding. On June 21, 2004, it made the first privately funded human spaceflight, and on October 4, it won the $10-million Ansari X PRIZE, by reaching 100 kilometers in altitude twice in a two-week period with the equivalent of three people on board, with no more than ten percent of the non-fuel weight of the spacecraft replaced between flights. Development costs were estimated to be $25-million, funded completely by Paul Allen.
During its testing regimen, SpaceShipOne set a number of important "firsts", including first privately funded aircraft to exceed Mach 2 and Mach 3, first privately funded spacecraft to exceed 100km altitude, and first privately funded reusable spacecraft.