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Mars Rover Has 'Amnesia' With Worn Out NAND Memory

Today we have some strange news for you: someone's SSD broke. Don't worry, we're not writing about your neighbor who managed to snap one in half, but rather about NASA's SSD. More specifically, the memory of the Mars Rover Opportunity.

When the Opportunity was deployed, what it had inside wasn't called an SSD – just "non-volatile flash memory" (which is exactly what an SSD is anyway). Now, after a decade of service, the researchers controlling the rover have pinpointed the source of its strange behavior. Namely, some of the NAND memory has gone bust after all these write cycles.

Image Source: Wikipedia

As you may know, non-volatile NAND memory has a limited number of write cycles that it can endure before it becomes worn out and won't store data properly anymore. Of the seven memory banks on the flash in the Rover, the seventh has issues.

The effect has been that the Mars Rover keeps trying to write data to the bank, but because of the way it's programmed, when it fails to write to it a certain number of times, it reboots. As a result, all the data that the rover had gathered into its RAM memory until that time hasn't been saved, making it a rather large pain to collect data effectively. The NASA staff calls this "amnesia," because the Rover keeps forgetting everything it has just done.

The solution to this problem is simply a software patch that stops the rover from using the seventh memory bank. After that, though, it's just a matter of time before another memory bank goes bad, or something else. Hopefully, NASA has included some kind of wear leveling algorithm with the software.

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Niels Broekhuijsen

Niels Broekhuijsen is a Contributing Writer for Tom's Hardware US. He reviews cases, water cooling and pc builds.