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Curiosity and other rovers issues with flash memory
Considering that flash memory is not knew, and is I understand used
extensively in the new capsule for humans and probably on the iss but I don't know that for sure, they do seem to be having a lot of issues with it corrupting. One assumes this is due to radiation, but it could also be due to some inherent instability caused by read/writes or temperatures experienced. Its interesting to see it happening already to the latest rover while its only just started to happen ont the older rover. I do hope someone is looking into this problem as its not a problem you really want if your crew is many days or months away from earth in some critical system. Brian -- Brian Gaff....Note, this account does not accept Bcc: email. graphics are great, but the blind can't hear them Email: __________________________________________________ __________________________________________________ __________ |
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Curiosity and other rovers issues with flash memory
"Brian Gaff" writes:
Considering that flash memory is not knew, and is I understand used extensively in the new capsule for humans and probably on the iss but I don't know that for sure, they do seem to be having a lot of issues with it corrupting. One assumes this is due to radiation, but it could also be due to some inherent instability caused by read/writes or temperatures experienced. Its interesting to see it happening already to the latest rover while its only just started to happen ont the older rover. I do hope someone is looking into this problem as its not a problem you really want if your crew is many days or months away from earth in some critical system. I'm fairly sure that this is just one of the problems you have to deal with by redundancy and backups. You can't expect to have no memory corruption (or outright failure) at all, even under the best circumstances. **** happens, everywhere and always, even in space. Jochem -- "A designer knows he has arrived at perfection not when there is no longer anything to add, but when there is no longer anything to take away." - Antoine de Saint-Exupery |
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Curiosity and other rovers issues with flash memory
That is true, but one would imagine that memory protection is rather a vital
thing to have issues with, considering the number of years its been on spacecraft. back in the old days they actually used to fly tape recorders as I recall.These tended to stick in the varying temperatures out there. Brian -- From the Sofa of Brian Gaff Reply address is active "Jochem Huhmann" wrote in message ... "Brian Gaff" writes: Considering that flash memory is not knew, and is I understand used extensively in the new capsule for humans and probably on the iss but I don't know that for sure, they do seem to be having a lot of issues with it corrupting. One assumes this is due to radiation, but it could also be due to some inherent instability caused by read/writes or temperatures experienced. Its interesting to see it happening already to the latest rover while its only just started to happen ont the older rover. I do hope someone is looking into this problem as its not a problem you really want if your crew is many days or months away from earth in some critical system. I'm fairly sure that this is just one of the problems you have to deal with by redundancy and backups. You can't expect to have no memory corruption (or outright failure) at all, even under the best circumstances. **** happens, everywhere and always, even in space. Jochem -- "A designer knows he has arrived at perfection not when there is no longer anything to add, but when there is no longer anything to take away." - Antoine de Saint-Exupery |
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Curiosity and other rovers issues with flash memory
"Jochem Huhmann" wrote in message
"Brian Gaff" writes: Considering that flash memory is not knew, and is I understand used extensively in the new capsule for humans and probably on the iss but I don't know that for sure, they do seem to be having a lot of issues with it corrupting. One assumes this is due to radiation, but it could also be due to some inherent instability caused by read/writes or temperatures experienced. Its interesting to see it happening already to the latest rover while its only just started to happen ont the older rover. I do hope someone is looking into this problem as its not a problem you really want if your crew is many days or months away from earth in some critical system. I'm fairly sure that this is just one of the problems you have to deal with by redundancy and backups. You can't expect to have no memory corruption (or outright failure) at all, even under the best circumstances. **** happens, everywhere and always, even in space. On Saturday, Brian Gaff queried: That is true, but one would imagine that memory protection is rather a vital thing to have issues with, considering the number of years its been on spacecraft. back in the old days they actually used to fly tape recorders as I recall.These tended to stick in the varying temperatures out there. Brian The type of Flash memory is also important. NOR-based Flash tends to be more stable, but costs more. It may also be slower. NAND-based Flash is dirt cheap, which is good because you have to provide a bunch of extra cells ... even on Earth, it is pretty much necessary to use ECC, and to use wear-leveling algorithms. Perhaps it was the ECC circuitry that triggered the failover. Note the redundancy: the error(s) occurred on the A-side computer and the B-side computer took over running the ship. And Curiosity's project manager says this: "The hardware that we fly is radiation tolerant, but there's a limit to how hardened it can be," Cook said. "You can still get high-energy particles that can cause the memory to be corrupted. It certainly is a possibility and that's what we're looking into." http://arstechnica.com/science/2013/03/flash-memory-issue-forces-curiosity-rover-into-safe-mode/ A quick look for relevant information doesn't lead me to any technical data on the Flash memory involved (2GB per computer, per Wikipedia), but I did see a comment by a veteran satellite programmer that there is only so much you can do in hardware to protect from these sorts of events (did it happen after a signficant solar flare?), so you always have software looking for errors. Which is what happened here. /dps -- But happiness cannot be pursued; it must ensue. One must have a reason to 'be happy.'" Viktor Frankl |
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Curiosity and other rovers issues with flash memory
On Monday or thereabouts, JF Mezei declared ...
It would be ironic if NASA were criticised for losing a ship because it used cheaper technology. Genereally they are criticised for using expensive tech. Cheap is a relative term; the rad-hardening is probably the biggest expense, and you can still expect to have upsets. Do these rovers have any sensors to measure solar radiation ? Seems this is an important metric to have if one is ever going to be building shelters for humans to camp in during the first mars expedition. I believe Curiosity is the first to be measuring that, and that the instrument was specifically included as a preliminary assessment of the human exposure. Surprise! JPL has a web page for this instrument! I didn't even need a secret handshake to find it! http://marsprogram.jpl.nasa.gov/msl/mission/instruments/radiationdetectors/rad/ /dps -- "This is all very fine, but let us not be carried away be excitement, but ask calmly, how does this person feel about in in his cooler moments next day, with six or seven thousand feet of snow and stuff on top of him?" _Roughing It_, Mark Twain. |
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Curiosity and other rovers issues with flash memory
Snidely wrote:
The type of Flash memory is also important. NOR-based Flash tends to be more stable, but costs more. It may also be slower. NAND-based Flash is dirt cheap, which is good because you have to provide a bunch of extra cells ... even on Earth, it is pretty much necessary to use ECC, and to use wear-leveling algorithms. It would be ironic if NASA were criticised for losing a ship because it used cheaper technology. Genereally they are criticised for using expensive tech. But big pictu what does this say about the chance that life ever existed on Mars ? Wouldn't an environment where solar radiation affects electronics also reduce the chance that life would survive long ? Do these rovers have any sensors to measure solar radiation ? Seems this is an important metric to have if one is ever going to be building shelters for humans to camp in during the first mars expedition. Given we have found bacteria living in the water of nuclear reactors, I'm sure stuff could survive on Mars. Especially since it most likely had a heavier atmosphere millennia ago. And given memory on Earth can be affected by radiation and we have plenty of life (not always intelligent life) I think Mars would do fine. -- Greg D. Moore http://greenmountainsoftware.wordpress.com/ CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net |
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Curiosity and other rovers issues with flash memory
"Greg (Strider) Moore" writes:
Do these rovers have any sensors to measure solar radiation ? Seems this is an important metric to have if one is ever going to be building shelters for humans to camp in during the first mars expedition. Given we have found bacteria living in the water of nuclear reactors, I'm sure stuff could survive on Mars. Especially since it most likely had a heavier atmosphere millennia ago. And given memory on Earth can be affected by radiation and we have plenty of life (not always intelligent life) I think Mars would do fine. Any life on Mars would be underground for more than one reason and protected from this. And there is even life down here (and not that primitive life either) that is fairly unimpressed by such levels of radiation: http://en.wikipedia.org/wiki/Tardigrades Nice image he http://www.bbc.co.uk/nature/12855775 Evolution does wonderful things. Jochem -- "A designer knows he has arrived at perfection not when there is no longer anything to add, but when there is no longer anything to take away." - Antoine de Saint-Exupery |
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