The Scaled Composites Model 318 White Knight (now also called White Knight One) is a jet-powered carrier aircraft used to launch the Scaled Composites SpaceShipOne experimental spacecraft. It was developed by Scaled Composites as part of its Tier One program. The aircraft was subsequently offered by Scaled on a contract basis as a research testbed, and was used for drop tests of the Boeing X-37spaceplane from June 2005 until April 2006. It is also the predecessor to White Knight Two which added a "one" to its name to tell the two apart.