Burt Rutan leads one of 27 teams from seven countries competing for the US$10 million X Prize, to be given to the first private entrepreneur who can put three people into sub-orbital space and do it again with the same equipment within two weeks - by the end of 2004.
The team is funded by Microsoft co-founder Paul Allen.
SpaceShipOne will piggyback aboard a mother aircraft known as the White Knight, to an altitude of 48,000 feet (14,600 metres). On release, SpaceShipOne's 18,000 lb thrust rocket engine burns for 80 seconds, accelerating the aircraft at three times the force of gravity to reach Mach 3.2 (3860kph) by the time the engine burns out at 160,000 ft (48,700m). Coasting the rest of the way, losing power and slowing down. At 200,000ft, the pilot - and passengers in the future - experience weightlessness, which lasts three to four minutes as the spacecraft attains its maximum altitude of 340,000ft, virtually stops, then falls back to 200,000ft (60,000m), when it begins to feel the atmosphere once again. The key is to decelerate gently in the upper atmosphere by controlling the angle during descent and maximising drag, making for a much safer and more comfortable ride.
SpaceShipOne, the rocket plane funded by Microsoft co-founder Paul G Allen, appeared to top its required altitude with-in minutes of firing its rockets in 2004. The plane took, off from a desert runway slung to the belly of a carrier plane with a test pilot at the controls. It was released at about 13,800m and fired its rockets to climb to an altitude of 100km.