Mars Odyssey orbiter experiences a problem

PASADENA, Calif., Dec. 1 (UPI) -- NASA scientists say they are trying to resolve a problem aboard the Mars Odyssey orbiter, which put itself into a safe standby mode Saturday.

Space agency engineers said the likely cause of the event was an upset in the orbiter's computer "memory error external bus," as was the case with a similar event in June 2008.

While in safe mode, Odyssey remains in communication with ground controllers and maintains its optimal temperatures and power, NASA said. To clear the memory error, the team Monday commanded Odyssey to perform a cold reboot of its onboard computer. Controllers said the spacecraft reported the reboot was completed successfully.

"This event is a type we have seen before, so we have a known and tested path to resuming normal operations," said Odyssey Project Manager Philip Varghese of NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Odyssey has been orbiting Mars since 2001, studying the planet and supporting the missions of the Mars rovers Spirit and Opportunity and the Phoenix Mars Lander.

Until Odyssey is available again as a communications relay -- expected in about a week -- NASA said Spirit and Opportunity will be operating with direct communications to and from Earth.