In 2004, Mike Melvill became the first civilian to pilot a craft into space. By flying to 100-km (62 miles) in altitude, SpaceShipOne left the Earth's atmosphere in a sub-orbital space flight. It was built by Burt Rutan and financed by Paul Allen. It began by riding piggy-back on its launcher White Knight to 46,000-ft (13.8-km) Then SpaceShipOne separated, glided briefly and fired its rocket for 80-sec to continue its trip to the edge of space. For re-entry, the ship's wings could swing into a new configuration for a 20-min glide back down to Mojave Airport, California. The 90-min flight ended with a safe landing on the desert airport runway. The rocket engine fuel was a solid rubber propellant with liquid nitrous oxide.«