SpaceShipOne sub-orbital flight. Illustration of the launch method used by the SpaceShipOne craft. It was flown to high altitude by its carrier craft White Knight (lower left). After release, it ignited its rocket to ascend outside the atmosphere to 100 kilometres altitude (top), before gliding back to Earth (lower right). SpaceShipOne was designed by the US company Scaled Composites. In 2004, it was twice flown to suborbital altitudes, winning the Ansari X-prize. Virgin Galactic planned to use this spaceship design to operate space tourism flights.