Over a decade of trudging on the Martian surface is finally taking its toll on NASA’s aging Opportunity rover. Opportunity, which has continued to study the surface of the red planet and beam data back to the Earth for over 40 times its designated lifespan of three months, is now reportedly facing troubling bouts of “amnesia.”
The Opportunity rover uses two different types of memory -- “volatile,” which is similar to a computer’s RAM, and “non-volatile,” or flash memory, which continues to store data even when the rover is powered down. The problem, Mars Exploration Rover Project Manager John Callas told Discovery News, is with Opportunity's flash memory.
“Flash memory has a limitation on how many times you can read and write to it … It wears out with use,” Callas reportedly said. “The problems started off fairly benign, but now they’ve become more serious -- much like an illness.”
As a result of the issues with the flash memory, Opportunity is automatically attempting to store data in the volatile memory, which is wiped out every time the rover powers down to allow its solar panels to recharge its batteries, Callas told Discovery News.
“So now we’re having these events we call ‘amnesia,’… it (the rover) stores telemetry data in the volatile memory, but when the rover goes to sleep and wakes up again, all the data is gone. So that’s why we call it amnesia -- it forgets what it has done,” Callas reportedly said.
Although there are times when the information is preserved because Opportunity is able to relay the data to the Mars Odyssey orbiter, which serves as a communications relay between the rover and Earth, most times important data is lost.
Moreover, as a result of the memory issue, the rover is also facing a bigger problem. Repeated attempts to save data to the flash memory are causing the rover to repeatedly reboot and forget the set of commands sent to it between two reboots.
“Basically the rover stops what it was doing because it wasn’t sure what caused the reset … it’s like you’re trying to drive on a family trip (and) the car stalls out every 5 minutes,” Callas reportedly said.
However, engineers at NASA have reportedly identified a glitch in one of the rover’s seven memory banks as the source of the problem. And, according to Callas, it could only be a matter of weeks before the issue is resolved.
“The rover has been amazingly healthy considering how much we’ve used it … we’re always cautious that something could happen,” Callas reportedly said.
Opportunity, which has been on the surface of Mars since January 2004, has traversed a distance of over 25 miles on the planet -- an extraterrestrial record for any rover.