This article has more info on the control system malfunction during SpaceShipOne's flight yesterday. It confirms my hunch that the planned altitude was considerably over 62 miles (they were shooting for 68 miles/110 km).

Aircraft developer Burt Rutan made a blunt assessment of the problem, which could have ended pilot Melvill's life and wrecked the $25m effort to demonstrate a passenger-carrying reusable suborbital spaceship.

"The anomaly we had today is the most serious flight safety systems problem that we have had in the entire programme," said Rutan, during a press conference following the flight.

"The fact that our back-up system worked and we made a beautiful landing makes me feel very good."

Rutan said the team was assessing a sudden roll seconds after SpaceShipOne's motor ignited and a more serious glitch that occurred when Melvill reached the highest peak of his suborbital flight.

He was attempting to tweak his altitude by manoeuvring the nose of the plane when the flight control system that operates flaps on the ship's wings failed.

Melvill activated the back-up system but the ship was already off course by 35km (22 miles).

The problem also ate into the engine performance during the climb to space and kept Melvill short of reaching his intended mark 110km (68 miles) above the atmosphere.

...

SpaceShipOne, however, is grounded until the team figures out why the flight control system failed.

"There is no way we would fly again without knowing the cause and without assuring we have totally fixed it because it's a very critical system," Rutan said.