NASA's Mars rover Curiosity is out of safe mode and back on active status after computer trouble had sidelined the vehicle for nearly a week.
The space agency reported that Curiosity is now running on its backup computer system, known as its B-side. It's been taken out of its minimal-activity safe mode and ready to return to full operation.
"We are making good progress in the recovery," said Mars Science Laboratory Project Manager Richard Cook in a statement.
"One path of progress is evaluating the A-side with intent to recover it as a backup. Also, we need to go through a series of steps with the B-side, such as informing the computer about the state of the rover -- the position of the arm, the position of the mast, that kind of information," he said.
Jim Erickson, Curiosity's deputy project manager, told Computerworld on Monday that engineers watching the rover's telemetry last week noticed certain applications would terminate mid-sequence. The cause, he noted, appears to be a file corruption.
"We are doing multiple things at the same time," said Erickson. "All we know is the vehicle is telling us that there are multiple errors in the memory. We think it's a hardware error of one type or another but the software did not handle it gracefully. We'd like to have our vehicles withstand hardware trouble and continue to function."
Now that NASA's computer specialists have fully switched the rover over onto its redundant, onboard computer system, they are trying to repair the problem on the main system. They also are attempting to shore up the rover's software so it can better withstand hardware glitches.
At this point, NASA engineers are looking to keep Curiosity running on the B-side system, while repairing the A-side so it can be on stand-by as the new backup.
NASA is on a deadline to get the rover fully functional before April 4, when communication with all Mars rovers and orbiters will end for about a month.
A solar conjunction -- when the Sun will be in the path between the Earth and Mars -- is fast approaching and will keep NASA engineers from sending daily instructions to the rover, or from receiving data and images in return.
NASA will have to send all operational instructions for that month-long span to Curiosity before the solar conjunction begins.
The rover will remain stationary in order to keep it safe while out of contact with Earth.
Curiosity, which landed on the Red Planet last August, is on a two-year mission to find out if Mars has ever had an environment that could support life, even in a microbial form.
