Why NASA's Opportunity rover is having problems with 'amnesia' on Mars

Contributed by
Dec 31, 2014

Though most of the attention is on NASA’s new-ish Curiosity rover currently rumbling around Mars, another craft has been exploring the Red Planet for the better part of a decade. Well, with old age also comes some memory problems.

The decade-old tech that powers NASA’s Opportunity rover is running into some major data problems, specifically what NASA techs are calling “amnesia” related to the way the craft saves and accesses memory. The craft uses two types of memory to record critical telemetry data, dubbed “volatile” and “non-volatile.”

One of those memory banks, the non-volatile area, is permanent. But the volatile memory clears every time the rover powers down (which is often, to conserve power). The problem? The equipment is breaking down, and the non-volatile memory bank is having problems saving. When that happens, the whole thing reboots — and all the data is lost. You can see where the problem comes in.

Here’s how Mars Exploration Rover Project Manager John Callas, of NASA’s Jet Propulsion Laboratory, explained the problem:

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

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.”

Luckily for NASA, they have a lot of big brains working the problem, and they seem to have figured out a way to fix it. Long story short: They’re going to essentially lobotomize the damaged memory bank causing all the problems and push out a software update instructing the rover to ignore it — instead storing all data on the (hopefully) healthy six remaining data banks.

The team is currently programming the fix, with hopes of pushing it out within the next month or two. Here’s hoping they get Opportunity back on track, since it's proven to be one of the most resilient pieces of tech ever built. It’d be a shame to have the mission succumb to something as seemingly simple as old-school forgetfulness. 

(Via Discovery)