The Scaled Composites Model 318 White Knight is a jet-powered carrier aircraft that was used to launch its companion SpaceShipOne, an experimental spaceplane. The White Knight and SpaceShipOne were designed by Burt Rutan and manufactured by Scaled Composites, a private company founded by Rutan in 1982. On three separate flights in 2004, White Knight conducted SpaceShipOne into flight, and SpaceShipOne then performed a sub-orbital spaceflight, becoming the first private craft to reach space.

SpaceShipOne is an experimental air-launched rocket-powered aircraft with sub-orbital spaceflight capability at speeds of up to 3,000 ft/s (2,000 mph) / 910 m/s (3,300 km/h) using a hybrid rocket motor. The design features a unique "feathering" atmospheric reentry system where the rear half of the wing and the twin tail booms folds 70 degrees upward along a hinge running the length of the wing; this increases drag while retaining stability. SpaceShipOne completed the first crewed private spaceflight in 2004. That same year, it won the US$10 million Ansari X Prize and was immediately retired from active service. Its mother ship was named "White Knight". Both craft were developed and flown by Mojave Aerospace Ventures, which was a joint venture between Paul Allen and Scaled Composites, Burt Rutan's aviation company. Allen provided the funding of approximately US$25 million.