NASA expects to get Cassini back on track soon

Computer-generated image of the Cassini orbiter

(CNN) -- Engineers should be able to put the Cassini space probe back in operation and back on track soon, following technical problems that caused the spacecraft to revert to safe mode earlier this week, NASA said Friday.

The problems began Monday at 2300 GMT when the probe detected a possible error in its spatial orientation and immediately suspended operations on all instruments not critical for its mission, said experts at the Jet Propulsion Laboratory (JPL) in Pasadena, California.

Communication between Cassini and Earth have been maintained, however, according to the JPL official in charge of the mission, Bob Mitchell.

Mitchell said engineering data from the spacecraft were being transmitted to Earth to help engineers pinpoint what caused Cassini to enter the safe mode.

JPL said engineers suspect that during a tracking maneuver, Cassini's star scanner may have viewed a patch of sky without the bright stars the spacecraft uses to orient itself in space.

Software would have alerted the system when the scanner had spent sufficient time searching for but not spotting familiar stars.

Mitchell said he expects Cassini will be taken out of safe mode later this week after the problem has been identified and data thoroughly analyzed.

Cassini was launched on October 15 from Cape Canaveral, Florida, over the objections of anti-nuclear protesters who feared what might happen if the rocket exploded while carrying Cassini and its 72 pounds of poisonous plutonium.

The spacecraft, on a $3.4 billion mission through the solar system, is expected to reach Saturn in July 2004. It passed Venus last year and this year will use Venus again and then swoop within 500 miles of Earth, an encounter that also worries Cassini opponents.