NASA engineers delete files from Spirit

LOS ANGELES -- NASA said Sunday its Spirit rover was a week away from rolling on Mars again and that the software problem vexing the spacecraft may trouble both it and its twin, Opportunity, for the duration of their double-barreled mission.

Engineers deleted more files from Spirit's flash memory but held off from reformatting it completely until today -- giving them more time to diagnose ongoing problems, mission manager Mark Adler said. NASA originally planned to perform the task Saturday.

The rover has been hampered by problems since Jan. 21, when it stopped transmitting intelligible information back to Earth.

Once its flash memory is reformatted, Adler said, Spirit should be able to leave the low-power mode, which has restricted nighttime operations, and begin operating normally again, by Tuesday at the earliest.

"Then I think we can declare we are completely back in our normal mode," Adler said during a conference call with reporters.

Continuing operation

Engineers will have to keep deleting computer files from Spirit's flash memory to keep their numbers low enough for the rover's random-access memory to manage. The same will be done for Opportunity.

Engineers also may regularly reformat the robots' flash memory, perhaps every week or two, Adler said.

Even with the computer glitch, engineers believe at least one of the 384-pound robots may last longer than their warranted 90-day lifetimes.

"I don't think the mobility side of the equation has hit us in the head yet," project manager Pete Theisinger said recently. "The first time we take a panorama and the lander's not there, it will hit home what we've accomplished."

NASA planned for Opportunity to reach out to the martian soil with its robotic arm for the first time today.

The six-wheeled rover rolled onto the dirt Saturday, a week after landing halfway around Mars from its twin, Spirit, which touched down Jan. 3.

Scientists expected Spirit to round out the weekend by making coordinated observations with Europe's Mars Express satellite as it flew over the rover's landing site, Adler said.

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