NASA: Mars rover goes quiet as Martian winter begins

Computerworld - Months after getting stuck in the Martian dirt, a NASA rover has stopped communicating with its controllers here on Earth.

The space agency said late yesterday that its Mars Exploration Rover Spirit did not make a communication session that had been scheduled for Tuesday. Scientists expect that the robotic machine has entered into a low-power hibernation mode, where most functions are ended to conserve valuable, and dwindling, energy.

"We may not hear from Spirit again for weeks or months, but we will be listening at every opportunity, and our expectation is that Spirit will resume communications when the batteries are sufficiently charged," said John Callas, project manager for Spirit and its twin Martian rover, Opportunity, in a written statement.

After six years roaming across and working on Mars, Spirit was deemed permanently stuck in the dirt on the surface of the planet in January.

NASA scientists, however, remained hopeful that the robot could still conduct experiments to help them better understand the planet. With the rover trapped in one spot, engineers at the space agency are concerned, however, that the machine won't survive the extremely frigid temperatures of the upcoming Martian winter.

Spirit got into trouble last year while working its way south near the western edge of a plateau NASA has dubbed Home Plate. The vehicle's wheels broke through the crusty surface and got stuck in some soft, salty sand underneath. Since then, NASA engineers have worked tirelessly to find a way to extricate the rover from the sand, but the vehicle now has two immobile tires on one side.

Spirit needs to be able to use solar energy to heat itself enough to make it through the frigid winter. NASA engineers tried to try to angle the vehicle's solar array so it's pointing more toward the sun. If the rover doesn't capture enough solar energy to wake up and run a few instruments, it may not generate enough heat to withstand the extremely frigid Martian winter.

Spirit's robotic twin, Opportunity, has been having better luck, however. NASA announced just last week that it outfitted Opportunity with a software upgrade that allows it to now make some of its own decisions.

Over this past winter, engineers uploaded artificial intelligence software to enable the rover to decide on its own whether it wants to stop and analyze rocks spotted during its travels across the Martian surface. The space agency noted that the upgrade will provide a good test of robotic autonomy, which it hopes to use more fully in future NASA space missions.

Sharon Gaudin covers the Internet and Web 2.0, emerging technologies, and desktop and laptop chips for Computerworld. Follow Sharon on Twitter at @sgaudin or subscribe to Sharon's RSS feed . Her e-mail address is sgaudin@computerworld.com.

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