2009-01-24

Spirit Sol 21

I wake up feeling much better, and after I hear the news on the radio I feel better still. We got data! KNX says we got 24 minutes' worth of data at the low rate, less than 8 bits per second. I immediately do the math in my head: 1400 precious bytes of data. Not much, but it's bound to help. And just the fact that we're getting data is good.

At JPL, I find clusters of worried people. I decide not to interfere with any of them; I have nothing to add, and I've got my own work to do anyway. I get back to work on my SCMF decoder.

Sure enough, sleep helped. In a couple of hours, I've nailed all of the remaining problems and put together a system for comparing the three sets of files. While I let that grind away, periodically making minor tweaks to improve the comparisons further, I watch the press conference on my Mac.

Today's story is better than yesterday's, and better than I heard on the radio. We got some data at 10bps and some at 120bps. The story is also worse: Pete says we expect no fix for days, maybe weeks.

To keep the whole press conference from being about Spirit's problems, they remind the press that Opportunity is landing tomorrow. And they talk about the Spirit EDL reconstruction. They show the video of the descent, built from actual data downlinked from Spirit; I've been hearing a lot about this video, which apparently has been floating around for a while, but I haven't seen it before. They also show images Mike Malin's MOC camera, aboard MGS, took of Spirit's landing site. You can see the bounce marks, the heat shield, and the lander itself. Mike Malin is insane! It's incredible that we can even do this -- we not only have a rover on another planet, we're taking pictures of the thing from 400km up!

But the reporters are naturally focused on what's wrong with Spirit -- as we are, to be fair. They ask Pete to make a medical analogy, and he tells them that if Spirit were in the hospital, its condition would be critical. I know instantly that that will be plastered all over the news, and I turn out to be right. Argh. They don't know what's wrong with Spirit yet, either. It might be a hardware "event"; we don't know what, or whether we can work around it. In response to a question about how we're handling this anomaly while Opportunity is coming down, Pete reassures them that we've split the teams, forcibly in some cases, thanks to the fact that "anomalies, to engineers, have a natural gravitational force."

So Spirit's broken, we don't know what's wrong with it, and we're not getting much data to help us figure it out. Until evening, when, to everyone's surprise, we get 73 Mbits during an Odyssey pass. Now that's more like it, Spirit, baby.

6 comments:

Dave said...

Scott, this is a daily must-read blog for me, thanks for taking the time to do it! I normally don't post comments on blogs, but I worry that you may take the relative lack of comments as a sign that nobody cares - believe me, that's not the case.

Anonymous said...

Scott, exactly what Dave said.

Vultur said...

I just found this blog yesterday, linked from Unmanned Spaceflight. This is exceptionally interesting - just the kind of details I've always been interested in about these missions.

peter said...

I'd like to second (third) what Dave said too. Thanks!

Anonymous said...

Is the video you mention in this post available from NASA? I'd love to see it. I've seen a pre-launch CGI video showing a simulation of a MER entering the atmosphere, eventually bouncing and then unfolding, but this sounds like something different and decidedly neat. In any case, more fascinating stuff!

Scott Maxwell said...

@Anonymous The video is here: http://marsrovers.jpl.nasa.gov/gallery/video/spirit01.html ... scroll down to sol 20.

Everyone else -- thanks for the encouraging comments!