Deep Space 1 Flames Out

The novel ion engine powering NASA's Deep Space 1 asteroid probe unexpectedly shut down on Tuesday, just minutes after being started for the first time. But space agency engineers believe the mysterious failure will only temporarily stall the $152 million mission.

Space scientists knew the 2.5-meter-long spacecraft, launched 24 October, was a risky venture. Its design is testing the feasibility of a dozen futuristic technologies, including artificial intelligence software that will help steer the craft to a rendezvous with an asteroid in July and the innovative ion thruster. The engine, which is lighter and more efficient than conventional combustion motors, uses a spray of ionized xenon molecules to nudge the craft through space. Though the engine's thrust is equivalent to little more than the pressure exerted by a feather resting on a person's skin, in the vacuum of space it can gradually accelerate spacecraft to great speeds over long distances.

But Deep Space 1 won't be speeding up anytime soon unless ground controllers can figure out how to restart the balky engine. Several restart attempts have already failed, but engineers at the Jet Propulsion Laboratory in Pasadena, California, are confident they will soon solve the problem, says spokesman John Watson. He notes that similar engines have exhibited temperamental behavior in ground tests. The flame-out, he predicts, will not sink the mission.