Deep Space probe's ion engine working smoothly, NASA says

Artist's conception of Deep Space 1

(CNN) -- The futuristic ion engine on NASA's Deep Space 1 probe is activated and has been running smoothly and gently for nearly two weeks, according to NASA.

The team originally powered up the engine November 10, but the system shut itself off after running for 4 1/2 minutes.

When controllers sent commands to the engine to turn itself on again last Tuesday, they planned to collect more data on the status of the system but believed it was unlikely the engine would keep running.

"We are very pleased that the engine started and continued to thrust," said Marc Rayman, Deep Space 1's chief mission engineer and deputy mission manager at NASA's Jet Propulsion Laboratory in Pasadena, California. "In fact, it has been running very smoothly over the first day of its operation."

Engineers believe that the engine probably shut itself off when it was first started because of metallic grit or other contamination between the two high-voltage grids at the rear of the advanced engine.

It is likely that changes in temperature as the spacecraft conducted other technology validation activities affected the flakes, and powering-up the thruster may have vaporized the remains, NASA said in a statement.

The October 24 liftoff

"It's common for new ion engines on the ground or on Earth-orbiting spacecraft to shut themselves off a few times when they are first exercised," Rayman said. "We would not be surprised if the engine shut itself off again over the first few days or weeks that it runs.

Described by mission officials as "a flying laboratory" for new space probe technologies, the budget-priced $152 million craft stands just 8.2 feet (2.5 meters) high.

Emitting a ghostly blue exhaust, its small engine expels ionized atoms of xenon gas at 65,000 mph (99,777 km/h) that push the craft forward.

Although the thrust from the propulsion system exerts less pressure than the weight of a single sheet of paper in the hand, each day it will add 15 mph to 20 mph (24-32 km/h) to the probe's speed.

Powered by electricity from solar panels and a supply of xenon gas, the ion propulsion system is 10 times more efficient than conventional rockets, according to NASA. The system can only be used in the vacuum of space.

Deep Space 1 is the first deep-space probe to rely on a solar-powered ion engine for primary propulsion. The engine must work as planned in order for Deep Space 1 to rendezvous with asteroid 1992 KD next July.