BY DR EMILY BALDWIN
Posted: 12 May, 2009
NASA’s Mars Exploration Rover Spirit is facing one of its biggest challenges yet with a patch of soft soil that is currently holding the rover hostage.
During recent attempts to drive around the Home Plate area of Mars, Spirit’s wheels have sunk about halfway into the ground. Concerns have been raised that Spirit may sink so low that its body may make contact with rocks on the surface, making the escape from this situation even more of a challenge. Engineers and scientists have temporarily suspended all driving while they simulate driving options with a test rover back on Earth.
Spirit took this image with its front hazard-avoidance camera on Sol 1899. With Spirit in the position shown here, the rover team temporarily suspended driving attempts while studying the ground around Spirit and planning simulation tests of driving options with a test rover at NASA's Jet Propulsion Laboratory in Pasadena. Image: NASA/JPL-Caltech.
“Spirit is in a very difficult situation,” says JPL’s John Callas, project manager for Spirit and its twin rover, Opportunity. “We are proceeding methodically and cautiously. It may be weeks before we try moving Spirit again. Meanwhile, we are using Spirit’s scientific instruments to learn more about the physical properties of the soil that is giving us trouble.”
Both Spirit and Opportunity have exceeded all expectations, operating more than five years longer than anticipated, and the rover team is becoming adept at developing workarounds for the aging rovers, such as the loss of use in one of Spirit’s six wheels three years ago.
At least the Martian weather is being kind – three times in the last month wind has removed some of the dust building up on the solar panels, increasing the rover’s capability for generating electricity. “The improved power situation buys us time,” says Callas. “We will use that time to plan the next steps carefully. We know that dust storms could return at any time, although the skies are currently clear.”
Behavioral problems that Spirit exhibited in early April – episodes of amnesia, computer resets and failure to wake for communications sessions – have not recurred in the past three weeks, though investigations have yet to diagnose the root causes.