Spirit rover communications status
I've been watching the briefing on NASA TV concerning the status of the two Mars missions (Spirit and Opportunity). It's amazing how much detail they give in the briefings compared to the amount of detail you can find in the press releases. I need to find transcripts.
What I was able to glean from the briefing is that they suspect a flash RAM problem on the rover is causing the software to fault when the rover is trying to boot, causing it to reset. It just resets over and over.
They were able to put the Spirit rover into what they call “crippled mode”, which sounds like a diagnostic mode that they can use when stuff is seriously broken. They requested that the rover enter this mode, and it did. It responded to other commands successfully, including a command to shut down early (before the end of it's normal communications window) and it did that - and then didn't respond to some pings after that, meaning it did successfully shut down. Knowing that it shut down was important since not being able to shut it down means it will just stay up until it drains it's batteries.
Very cool. They've had to deal with working around hardware failures before, and I expect they will be able to recover from this.
In my own estimation, it's either a flash RAM hardware problem, meaning they can figure out what part of the RAM is bad and map it out, or it's a software problem (something like the file system on the flash RAM is corrupt) and they can rebuild it. I'm oversimplifying it by a lot, but I still remain optimistic.
And of course Opportunity lands at around midnight (EST) tonight!