Bogged-down Mars rover may be doomed to chilly death
Unable to point solar panels at low midwinter sun
NASA says that its "scrappy" Mars rover, Spirit - which has spent six years prowling the ochre wilderness of the red planet - may finally be stuffed. Bogged in a sand trap, the machine is unable to align its solar panels correctly for the coming Martian winter, meaning that it will probably expire from the cold.
According to a NASA statement, Spirit's panels are currently tilted by five degrees towards the south. This is bad news, as the rover is in the southern hemisphere with winter approaching - soon the sun will be low in the northern sky, barely shining on the cells at all. It would be much better if Spirit could get onto a north-facing slope and tip the cells that way.
"At the current rate of dust accumulation, solar arrays at zero tilt would provide barely enough energy to run the survival heaters through the Mars winter solstice," says Jennifer Herman, a rover power boffin at NASA's Jet Propulsion Laboratory. If the heaters can't be kept on through the severe Martian midwinter, the rover will probably expire permanently.
"The highest priority for this mission right now is to stay mobile, if that's possible," said Steve Squyres, capo di tutti boffini for the rovers.
But that doesn't seem terribly likely. Spirit got stuck in its current sand trap in the Gusev crater some nine Earth months ago, and efforts to date have "barely budged" it, according to NASA. Attempts to get the trundling robot free have been hampered by the fact that one of its six wheels hasn't worked properly since 2006, and another one packed up last month.
NASA engineers think that they may be able to improve the rover's tilt even if they can't get it moving again, by scientifically revving different wheels. Apparently it could still offer valuable service even if it has to remain stationary.
"Spirit could continue significant research right where it is," said Ray Arvidson, number two on the rover team. "We can study the interior of Mars, monitor the weather and continue examining the interesting deposits uncovered by Spirit's wheels."
Martian southern-hemisphere midwinter will arrive in May. NASA is to hold planning and assessment meetings regarding its various ongoing programmes this February. Spirit has already hugely outlasted its planned duration, having been originally expected to keep operating for just three Earth months following its landing on Mars in January 2004.
The rover has an "uncertain future", the space agency says. However there's no suggestion of any cloud hanging over its companion rover, Opportunity, still crawling across the Meridiani Planum on the other side of Mars. ®