NASA says it has absolutely no plan to turn off either of the Mars Rovers because of budget cuts.
NASA is saying Tuesday that it has rescinded a letter that recommended budget cuts in the Mars Rover program to cover the cost of a next-generation rover on the Red Planet.
The move comes a day after scientists at the agency's robotics center said they would need to hibernate one of the twin Mars robots and limit the duties of the other because their budget was being cut by $4 million.
That announcement was based on a letter NASA sent to the Jet Propulsion Laboratory in Pasadena last week.
But NASA is saying in a statement Tuesday that neither of the rovers will be shut down.
The original news had come amid belt-tightening at NASA headquarters, which is under pressure to cover cost overruns of a flagship Mars mission to land a Hummer-sized rover on the Red Planet next year.
The solar-powered rovers Spirit and Opportunity have dazzled scientists and the public with findings of geologic evidence that water once flowed at or near the surface of Mars long ago.
Both rovers were originally planned for three-month missions at a cost of $820 million, but are now in their fourth year of exploration. It costs NASA about $20 million annually to keep the rovers running.
The directive from NASA to cut $4 million had meant Spirit would have been forced into hibernation in the coming weeks, said principal investigator Steve Squyres of Cornell University.
"It's very demoralizing for the team," Squyres said before NASA rescinded the letter.
Spirit is parked on a sunny slope for the Martian winter and was going to gather atmospheric measurements before the budget cut. Instead, it will now stay in sleep mode for most of the winter and stop all science gathering.
The funding cut was announced in a letter delivered Wednesday to NASA's Jet Propulsion Laboratory in Pasadena.
JPL, which manages the rovers, will not appeal the cut.
Through a spokesman, NASA Administrator Michael Griffin said late Monday he was against terminating a rover.
Agency spokesman Dwayne Brown did not say whether funding would be restored to the rovers or whether cuts would be made to other Mars projects for Spirit to keep operating.
The cut comes at a time when the robots are in the midst of an extensive exploration campaign, said deputy principal investigator Ray Arvidson of Washington University in St. Louis.
"We're not done. There is still a lot to explore," Arvidson said.
Besides resting Spirit, scientists also likely will have to reduce exploration by Opportunity, which is probing a large crater near the equator.
Instead of sending up commands to Opportunity every day to drive or explore a rock, its activities may be limited to every other day, said John Callas, the Mars Exploration Rover project manager at JPL.
"Any cut at any time when these rovers are healthy would be bad timing," Callas said. "These rovers are still viable capable vehicles in very good health."