10 Years In, Mars Rover Opportunity Suffers From Flash Memory Degradation

astroengine writes Mars Exploration Rover Opportunity has been exploring the Martian surface for over a decade — that's an amazing ten years longer than the 3-month primary mission it began in January 2004. But with its great successes, inevitable age-related issues have surfaced and mission engineers are being challenged by an increasingly troubling bout of "amnesia" triggered by the rover's flash memory. "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," Mars Exploration Rover Project Manager John Callas, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., told Discovery News.

Comments

I'm sorry

[rossdee]

But to claim it under warranty, you have to return it to the manufacturer

Re:I'm sorry

[thoriumbr]

Too bad you must pay the shipping...

depends on why bank 7 has problems

[Anonymous Coward]

http://mars.nasa.gov/mer/mission/status_opportunityAll.html

I don't know that one could expect similar behavior from the other banks on a similar schedule. This is fairly old technology in terms of design and software, so I don't think they're doing any sort of automatic wear leveling, for instance. It's probably "manually leveled" if at all. For all we know, bank 7 was used the most and it's worn out. Or, it's taking more total ionizing dose (TID) because of the physical location on the card. Or, it's just a process variation when making the flash chips themselves. They were probably fabricated in 2000, most likely at Micron, since for a 2003 launch, the computer was probably assembled by early 2002, if not earlier.
Or, the software is not optimized for "space flight use" but, rather, for "consumer camera memory card", which has a different read/write/erase pattern and error tolerance.

http://spinroot.com/gerard/pdf/25MC.pdf describes an improved file manager under development, but also describes the existing flash architecture.

Re:Why are we still fighting with this?

[Guspaz]

Explain how the results of research done two years ago could have been built into a probe launched ten years ago using technology from twenty years ago?

Re:Why are we still fighting with this?

[bledri]

This was known, and should have been exploited:

Although subjecting the cells to high heat could return memory, the process was problematic; the entire memory chip would need heating for hours at around 250 C.

The rover is equipped with heaters. There is some possibility that simply placing the flash closer could have extended the life of the memory.

The rover's primary planned mission was 3 months and the extended mission plan was two years. It lasted 10 years and your upset they didn't design a way to bake the flash (offline) for four hours at 250C? Self heating flash did not exist, should they heat all the electronics? Invent a mechanism to remove the flash and put it in a little oven? Are you shutting down the rover's computer for this? How much complexity would that have added? How long would it take to develop?

There is such a thing as "good enough," and engineers that don't know that never ship usable product.