GUY NORRIS / LOS ANGELES
Supersonic aircraft reaches Mach 1.2 but runs off Mojave runway on landing
SpaceShipOne, the Scaled Composites low-cost suborbital demonstrator, broke the sound barrier on 17 December before running off the Mojave runway on landing after one of its undercarriage legs collapsed.
The supersonic sortie was made possible by the first airborne firing of the vehicle's SpaceDev/Scaled Composites hybrid rocket motor, which uses pressure-fed nitrous oxide as an oxidizer and hydroxy-terminated polybutadiene as the solid fuel.
The rocket motor was fired shortly after SpaceShipOne was released from the White Knight mothership at 48,000ft (14,640m). Piloted by Brian Binnie, the vehicle accelerated from Mach 0.55 to around M1.2 during the 15s burn of the rocket. During the initial acceleration the vehicle climbed at a 60° angle and, following engine shutdown, was put into a vertical climb before achieving zero speed at 68,000ft.
The vehicle was then configured into its high-drag "feathered" shape for a 1min-long descent phase to simulate an atmospheric re-entry. This also reconfirmed the results of a series of recent glide tests undertaken over recent months to evaluate aerodynamic modifications made to correct an uncommanded pitch-up problem uncovered during a glide test in September. During later tests Scaled Composites intends to demonstrate zero-g conditions at apogee for more than 3min.
After reconfiguring SpaceShipOne from its feathered position, Binnie restored the vehicle to its more conventional glider shape for a 12min gliding descent.
On touchdown, Scaled Composites says the left gear "retracted, causing the ship to veer to the left and leave the runway with its left wing down". The company, which is proposing SpaceShipOne for the $10 million X-Prize, says "damage from the landing incident was minor and will easily be repaired. There were no injuries."
Scaled Composites, which timed the test attempt to coincide with the centenary of flight, says the achievement marks the first supersonic flight by an aircraft developed by a small private company without government support. Shortly after the flight, Microsoft co-founder Paul Allen confirmed his role as the sponsor of the project.
Last year Scaled Composites founder Burt Rutan said that $20 million was a good estimate for the project's cost.
Source: Flight International
