Jessica Griggs, New Scientist intern
Spirit, the rover exploring Mars, has lasted twenty times longer than anyone thought it would. But this week there were signs that it's succumbing to old age.
On Sunday the Mars Exploration Rover team, at NASA's Jet Propulsion Laboratory in Pasadena, California, revealed that Spirit had been behaving erratically and suffering a bout of memory loss.
When the team made contact with Spirit, on its 1800th day on the red planet, they found that even though it had received the day's driving instructions loud and clear, it had failed to budge. It also failed to record the day's main activities. "It's almost as if it had amnesia for an hour and a half," John Callas, the mission's project manager, told New Scientist.
Spirit's memory loss might be explained by incoming cosmic rays
playing havoc with its electronics.
The team think that Spirit failed to move because it has problems with the onboard gyroscopes, which the rover uses to find the sun so it can orientate itself. Gyroscopes have a finite lifetime and then become unstable, drifting over time, Callas explained.
On Tuesday, the team used the lander's panoramic camera to get a location fix by instructing it to take a series of imaging loops around the sky. It managed to track down the sun but found itself in an unexpected location. "This tells us that something more serious is going on," Callas said
According to Callas, Spirit is reporting that it's in "good health" by Wednesday
and the team is carrying out diagnostic tests to work out exactly what
went wrong.
The problems are unsurprising, whatever their cause, since Spirit and its twin Opportunity are getting on a bit. They've had a prosperous career, sending more than a quarter-million
images and 36 gigabytes of data back to Earth, covered more than 13
miles, excavated the soils, climbed a mountain, descended into craters and survived dust storms.
It's going to be rather sad when the two rovers succumb to old age and stop reporting.