MOJAVE, Calif. - Ignoring a warning to abort the flight, a test pilot took a stubby-looking rocket plane on a corkscrewing, white-knuckle ride past the edge of the atmosphere Wednesday, completing the first stage of a quest to win a $10 million prize.
As spectators and controllers nervously watched from the ground, SpaceShipOne rolled dozens of times as it hurtled toward space at nearly three times the speed of sound. It reached an altitude of 64 miles over the Mojave Desert.
Spaceship designer Burt Rutan said he asked pilot Michael Melvill to shut down the engine, but Melvill kept going until he reached the altitude specified under the rules for the Ansari X Prize, a bounty offered to the first privately built, manned rocket ship to fly in space twice in a span of two weeks.
''I did a victory roll at the top,'' Melvill joked from atop the spaceship after it glided safely to a landing.
The problem was being analyzed by the spacecraft's builders, who must decide whether to proceed with another flight Monday in order to win the X Prize.
But Rutan and Melvill were confident the flight would go on as planned. Rutan said rolling occurred during flight simulations, and it was not a complete surprise when it happened Wednesday.
''I've looked at it, and I think we just change out the engine and fill it with gas and let it go,'' Melvill said.
The test pilot said he may have caused the rolling himself. ''You know, you're extremely busy at that point. Your feet and your hands and your eyes and everything are working about as fast as you can work them, and probably I stepped on something too quickly and caused the roll.''
SpaceShipOne, with Melvill at the controls, made history in June when it became the first private, manned craft to reach space.
The Ansari X Prize will go to the first craft to safely complete two flights to an altitude of 328,000 feet, or 62 miles - generally considered to be the point where the Earth's atmosphere ends and space begins - in a 14-day span. The St. Louis-based X Prize Foundation is offering the bounty in hopes of inspiring an era of space tourism.
Rutan, with more than $20 million from Microsoft billionaire Paul Allen, secretly developed SpaceShipOne and is well ahead of two dozen teams building X Prize contenders around the world.
The mission began when a specially designed jet with the ship under its belly took off from the desert north of Los Angeles. At 47,000 feet, SpaceShipOne was released, and Melvill fired its rocket motor and pointed the nose toward space.