The Scaled Composites Model 339 SpaceShipTwo (SS2) is an air-launched suborbital spaceplane type designed for space tourism. It is manufactured by The Spaceship Company, a California-based company owned by Virgin Galactic.
The first generation engine was developed by Sierra Nevada Corporation (SNC) from the late 2000s to may 2014. It was first ignited in flight during a SpaceShipTwo test launch in April 2013. In 2014 Virgin Galactic ended contract with SNC and replaced it with its own internally developed hybrid motor.