This is such sad news; I can’t help but anthropomorphize these robots.
NASA’s Opportunity rover has been crippled and blinded by problems with two of its most important instruments. The agency has suspended work involving the rover’s rock grinding tool and its infrared spectrometer while engineers try to work out a fix.
The problems are the latest in a long line of failures that have begun to plague both rovers as they age.
Opportunity and its twin, Spirit, were designed to last just 90 days. But they have been driving around the Red Planet for nearly 4 years, having landed in January 2004.
The two rovers have already experienced several parts failures. Spirit’s right front wheel seized up in March 2006, due to a broken motor. Since then, the rover team has been driving Spirit in reverse and dragging the dead wheel in order to compensate for the problem.
Opportunity’s right front wheel is also injured. It can still spin, but since April 2005, it has no longer been able to turn in different directions to help the rover make turns. Opportunity can still drive reasonably well, however, since the other front wheel and the two back wheels can still swivel.
An “arthritic” instrument arm has also caused problems for Opportunity, a problem that cropped up in November 2005. The motor at the arm’s shoulder joint has degraded and is not producing as much torque as it was designed to.
Both rovers are experiencing problems with “encoders” on their rock grinding tools, which tell the rover computers whether the grind head is moving or not.
As for Spirit, it is facing the prospect of a very difficult winter because of the amount of dust on its solar panels. Winters are darker and colder for Spirit, which is farther away from the equator than Opportunity.
“We’re going into the next Martian winter with more dust than we’ve ever had on [Spirit’s] solar arrays,” Callas says. “We think it will survive, but it’s going to be close.” For most of the winter, what little energy Spirit gets will be spent keeping its electronics alive.
Despite the various age-related problems, Callas is optimistic about the future of the rovers. “I’m planning to keep these rovers going for years more,” he says. “They’re still very effective robotic geologists.”
If the rovers had only lasted for the 90 days they were intended, I don’t think it would be upsetting at all to learn that they were falling apart, nearing the end of their life. But something about their unexpected tenacity so far away, in such a hostile environment, makes them endearing.