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Free Spirit: Mars Rover Has an Escape Plan

The Mars rovers are true survivors. Although Spirit and Opportunity were slated to work for just 90 Martian days, they’ve been putting in some serious overtime—they’re now at just over 2,000 days on the job and counting.

For its part, Spirit has continued toiling away on Mars even after it broke a “foot,” wore down one of its favorite tools, almost starved due to a strong dust storm blotting out sunlight, and suffered a series of memory glitches.

Then, this past May, the robust rover got stuck in the sand.


A screen shot from a computer simulation shows Spirit’s current predicament.

—Picture courtesy NASA/JPL-Caltech

In the midst of a routine drive near Gusev crater, Spirit broke through a thin crust of soil over a filled-in crater. Its wheels became half buried in the soft sand, and the rover was struggling to gain traction on the slippery sulfates below.

So Spirit has stayed put for months while mission managers on Earth have raced to come up with an escape plan.

On Monday, NASA says, after working various tests, computer models, and presumably late nights, engineers will make the first attempt to free the venerable rover.

“This is going to be a lengthy process, and there’s a high probability attempts to free Spirit will not be successful” Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters, said in a statement.

“Mobility on Mars is challenging, and whatever the outcome, lessons from the work to free Spirit will enhance our knowledge about how to analyze Martian terrain and drive future Mars rovers,” McCuistion said.

The drive to freedom will start with a forward march up a mild slope, which mission managers hope will steer Spirit past a rock lying underneath. Data collected from the first drive attempt will help NASA figure out its next move, and it’s anticipated that efforts to edge Spirit out of the crater will continue into early 2010.

But even if the rover can’t be budged, Spirit has been learning a lot from its unexpected surroundings.

“The soft materials churned up by Spirit’s wheels have the highest sulfur content measured on Mars,” said Ray Arvidson, deputy principal investigator for the science payloads on Spirit and Opportunity.

“We’re taking advantage of its fixed location to conduct detailed measurements of these interesting materials.”