With spring underway on Mars, NASA is taking advantage of the Martian season’s ever-longer periods of daylight to try to reawaken its stuck rover, Spirit, after months of silence.

The Mars Spirit rover has been dormant since March 22, 2010, but mission controllers at the Jet Propulsion Laboratory in Pasadena, Calif., are hopeful that the rover survived the harsh Martian winter and will wake up any day now.

“The amount of solar energy available for Spirit is still increasing every day for the next few months,” said John Callas, NASA’s Mars rover project manager at JPL. “As long as that’s the case, we will do all we can to increase the chances of hearing from the rover again.”

NASA’s Mars rover team had anticipated that Spirit would enter a hibernation-like low power mode during the long winter season, with minimal activity except for charging and heating its batteries and keeping its internal clock running.

With most heaters shut off, Spirit’s internal temperatures dropped to the coldest ever experienced by the rover on Mars. That stress may have caused damage, such as impaired electrical connections, that would prevent reawakening or, if Spirit returned to operation, reduce its capabilities.

After mid-March, when the days on Mars once again grow shorter, the prospects for reviving Spirit will begin to drop, NASA officials said.

Communication strategies will shift, based on the reasoning that Spirit’s continued silence is probably due to factors beyond low power. NASA officials say they will consider it a real possibility that damage from the winter’s cold ended Spirit’s mission.

Spirit landed on Mars in January 2004 to look for evidence of past water activity. The mission was originally designed to last for three months, but Spirit put in nearly six years of extended duty.