NASA says its powerful Mars Reconnaissance Orbiter is in safe mode after being hit by a cosmic ray or solar particle.
The spacecraft abruptly rebooted its onboard computer Wednesday night, but can still send down engineering data to ground controllers.
The orbiter is "power positive, batteries fully charged, sun-pointed and thermally safe," Jim Erickson, project manager at NASA's Jet Propulsion Laboratory in Pasadena, said in a status report issued Thursday.
Crews at the Jet Propulsion Laboratory in Pasadena have been "cautiously bringing the orbiter back to normal operations," Erickson said. Science observations could resume as early as next week.
The Mars Reconnaissance Orbiter was launched in 2005 and entered Martian orbit in 2006. The spacecraft's initial two-year, $720 million mission has been extended to at least 2010.
NASA said Wednesday's reboot was reminiscent of a similar safe-mode event that occurred on Feb. 23. In that case, engineers suspected that a cosmic-ray hit caused a brief power surge, which in turn triggered a reboot.
This report includes information from The Associated Press and msnbc.com.