NASA's Opportunity Mars rover is experiencing what the space agency has identified as "amnesia" and needs to troubleshoot ways to fix the problem.

Speaking with Discovery News, Mars Exploration Rover Project Manager John Callas detailed what is going wrong with Opportunity. Launched in Jan. 2004, the rover's mission has spanned an Earth decade even though it's primary objective was only supposed to last three months.

"The mission can continue without storing data to flash memory, and instead store data in volatile RAM," Callas, of NASA's Jet Propulsion Laboratory, said in a recent press release.

Flash memory is stored even when the rover is in idle mode, during which time the machine can perform basic operations, but not add new data. That is known as non-volatile memory. On the other hand, volatile data is beamed to Earth before the rover calls it a day because that information cannot be stored in idle mode.

"The difference is non-volatile memory remembers everything even if you power off, in volatile memory everything goes away," Callas told Discovery News. "So volatile memory is like the traditional RAM you have in your computer; non-volatile memory uses flash memory technology."

Now, likely because of wear and tear and old age, Opportunity's flash memory is failing.

"The problems started off fairly benign, but now they've become more serious - much like an illness, the symptoms were mild, but now with the progression of time things have become more serious," Callas said. "So now we're having these events we call 'amnesia,' which is the rover trying to use the flash memory, but it wasn't able to, so instead it uses the RAM... it stores telemetry data in that 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."