Phoenix Flash Memory Problem
Published on Jun 19, 2008 at 6:49 pm.
4 Comments.
Filed under Mars.
According to a JPL press release, the Phoenix lander on Mars recently had an issue with its flash memory. You can read more about the incident on Emily Lakdawalla’s blog posting about it. Flash memory is a nonvolatile memory such as that used in memory sticks. The RAM on board the spacecraft loses data when it is powered down for the night. But, the flash memory holds onto the data. Flash memory is very durable, so it is normally a safe way to store data. However, Tuesday night, Phoenix lost some data when it powered down. Apparently what happened was that there was not enough memory to hold onto all of the data that was trying to be stored. The spacecraft stores not just science data, but also information about spacecraft operations, too. Maintaining the health of the spacecraft obviously has high priority. After all, if you lose the spacecraft, then you lose all future science data. Normally, there isn’t all that much spacecraft data that needs to be stored, so there is plenty of room on the flash memory for science information. Apparently, though, something happened Tuesday to cause the spacecraft to store a great deal more spacecraft data than normal. That didn’t leave room for all of the science data. So, when Phoenix powered down, the science data was lost.
The data that was lost was, for the most part, not all that critical. It was mostly images. And, of course the cameras can take more pictures, so that is not a big deal. Apparently, the robotic arm did do a bit of digging, and not all of the images taken of the ground before the digging got transmitted to Earth, so that information is lost, but that is likely not a major deal. What is worrisome, though, is why the spacecraft had so much housekeeping data that it displaced science data. The Phoenix team is working on that, though. For now, the plan is to make sure that the science data is transmitted back to Earth, if at all possible, before powering down the spacecraft. In the meantime, they are trying to make sure that this won’t happen again, even if they don’t transmit all the data back home.
When I heard about a problem with Phoenix’s flash memory, it reminded me of a far more serious problem that the Mars rover Spirit had with its flash memory. Nearly four and a half years ago, Spirit was having a problem where it rebooted several times per day. That problem was solved by reformatting the flash memory. The problem with Phoenix sounds different. Hopefully, they’ll quickly figure out the problem and be able to correct it. They don’t seem too worried about the situation, though, so that is good.
-Astroprof
Image courtesy NASA, JPL
Ed Minchau on June 19, 2008 at 9:11 pm: 1
Perhaps more interesting than the flash memory problem: Phoenix found ice!
http://www.spaceref.com/news/viewpr.html?pid=25708
Harith on June 20, 2008 at 12:41 am: 2
Such things are worrying.
CCPhysicist on June 20, 2008 at 10:05 pm: 3
I like that one of the auto-generated ads is for flash memory. They even offer “same day shipping”! I wonder if they send things to the Mars zip code.
MsLaurel on June 21, 2008 at 7:19 pm: 4
One can never have too much memory. What were they thinking?