Engine stalls on NASA's Deep Space probe

Artist's conception of Deep Space 1

CAPE CANAVERAL, Florida (AP) -- The futuristic ion engine flying on NASA's Deep Space 1 probe mysteriously shut down within minutes of being turned on this week, and ground controllers were trying to figure out what went wrong.

The ion-propulsion engine ran for 4 1/2 minutes Tuesday before turning off, said John Watson, a spokesman for the Jet Propulsion Laboratory in Pasadena, California. Ground controllers tried several times without success to restart the engine.

It was the first time since Deep Space 1's launch 2 1/2 weeks ago that controllers turned on the ion engine, the most intriguing of 12 "Star Trek"-style technologies being tested on the $152 million mission.

The engine must work in order for Deep Space 1 to rendezvous with asteroid 1992 KD next July.

Deep Space 1 is the first deep-space probe to rely on a solar-powered ion engine for primary propulsion. The spacecraft was nearly 2 million miles from Earth on Wednesday, thanks to the kick of the conventional rocket used to launch it on October 24.

Watson said similar shutdowns have been observed during ground tests and on communication satellites equipped with ion engines.

The October 24 liftoff

"They have lots of options they're investigating" to get the Deep Space 1 engine running, he said Wednesday.

Ions are electrically charged particles. A high-speed stream of xenon ions is supposed to provide a gentle yet constant acceleration for Deep Space 1.

Ion engines are seen as preferable for future spacecraft because they require only one-tenth the fuel of conventional chemical engines and can therefore use smaller and cheaper rockets for launch.