They're running the same flight software, but the parameters are different. (A parameter might say, for example, how far to drive between autonomous visual odometry updates, or how big the bounding boxes around the arm should be when computing ChemCam laser safety.) There are thousands of these parameters, and they're not routinely kept up to date on the non-prime side (which has historically been the B side).

And while the computers are identical, the non-cross-strapped equipment isn't. For example, the B-side rear HAZCAMs are exposed to more radiation, because of the DAN instrument, than the A-side rear HAZCAMs, and are therefore expected to degrade faster. Switching back to the A side is, generally, switching back to slightly better equipment.

Well, technically, I did the other arm work for the sol (the MAHLI and APXS placements) so that Joe and Diana could focus on the DRT.

Nothing to add, really, just bragging. :-) Thanks for the continued interest in MSL, Slashdot!

Yes, but don't worry: that massive amount of info they're collecting on you as part of HSPD-12[*] is perfectly safe.

[*] Where NASA said we all had to submit to unrestricted background investigations -- where they could gather any data they wanted on you, from any source, whether it be your doctor, your lawyer, your priest, your ISP, or whatever -- and then a secret, unappealable tribunal would decide if we could keep our jobs. I and others sued them over this, and lost. But don't worry, we can all see that NASA keeps careful track of sensitive information.

Yeah, I know what you mean. There's this guy who burgled my house 20 years ago. And 19 years ago. And 18 years ago, and so on. Even when the cops caught him, he was never punished -- just set free to burgle my house again. But he didn't burgle my house last year, so I'm not mad.

I wonder why people around here hate Microsoft?

Both ends of this are wrong, at least in the short to medium term: our data's not that accessible, and most things you call the help desk for are not Googlable (if that's a word). Things like JPL's internal policies and procedures, for example -- we have an internal, Google-based search engine, but it's not able to find everything by a long shot.

Also, as it happens, our help desk is very good -- even if it is run by Lockheed Martin -- and it would actually be a shame to see it go away. This might change someday, but right now, humans are irreplaceable.

These LEGO figurines look awesome! My hat's off to the JUNO team!

We sent (flattened) LEGO figurines aboard the MER landers, too (not on the rovers proper). Their names were Biff Starling and Sandy Moondust, if I recall correctly. See my blog for a terrific color picture of Spirit's LEGO figurine before she drove away.

The MER landing system was pretty damn complicated as well -- you shouldn't think otherwise just because it worked perfectly, twice. (And the late add of the DIMES system, which used images taken during descent to make decisions about rocket firing, made things even more complex but probably saved Spirit.)

I know some of the engineers working on the MSL landing system, and they're well aware that it all needs to work properly. They're also terrifically smart, the kind of people who can make this work if anyone can.

Do I think it's a guaranteed success? Of course not: guaranteed successes don't happen in this business. But I also recognize that it's not more complex than it needs to be, to solve this very hard problem.

(Yeesh, let's try that again.)

Here's a remix of that xkcd strip that the MER team liked better than the original: http://twitpic.com/52etk7.

Goodbye, Spirit, love, and well done.

Verizon will unblock port 25 if you ask them. They did for me. I hope that helps!

(Disclaimer: I'm a named plaintiff in this lawsuit.)

I'm only about halfway through the ruling, but it's hard for me to know where to begin criticizing it. Here are some choice bits:

* The ruling says that we shouldn't be worried because the government promises to protect our privacy. That's fatally absurd in the era of Wikileaks: if the government can't keep its own secrets secret, what are the odds that it'll keep my secrets secret?

* The ruling says that the government needn't show that its questions must be crafted as narrowly as possible to further its interests. This seems to ignore an interesting distinction between the government and private employers: the government can now ask you anything it wants, and jail you if it doesn't like the answers. Worse, the government can change its mind about what you get in trouble for, as a lot of people discovered unpleasantly in the 1950s, so something that's perfectly safe to admit now can get you in trouble a decade from now.

* It's a special irony that Justice Thomas held (in a minority view) that there's no right to informational privacy at all. (Fortunately, the majority explicitly refused to rule on that point.) Perhaps Justice Thomas would like to tell us what really went on between him and Anita Hill, then? Or maybe privacy is good for the gander, in his view, but not so much for the goose.

* Remember that this ruling is only on a preliminary injunction. We haven't even gone to trial yet. The legal system is as intricate as only a centuries-old piece of code can be, and we have a long way to go yet. (Contrary to a highly misleading internal all-hands JPL email message issued after the ruling, incidentally.)

I have lots more to say, but I'm going to meet with our lawyers now. Grr.

As a named plaintiff in this lawsuit, I'm awfully happy to see the widespread support here on Slashdot. I'd like to be able to keep driving Mars rovers around without having to sign a form that says NASA can interrogate my priest, my doctor, my lawyer, my accountant, and my ISP to make sure I'm sufficiently uninteresting.

If you'd like to help, please consider donating to keep our amazing legal team afloat. The privacy you save could be your own. Thank you!

We never particularly expected to hear from Spirit before this coming October +/- 1 month, making the suggestion that we're "beginning to realize she might never wake up again" more than a little misleading. According to our best models, the energy levels on Mars are just barely reaching the point where Spirit might wake up for even a few minutes a day, and hearing anything from her at this point would be a great stroke of luck. Have patience. She's there.

I understand that NASA is trying to manage expectations, but their way of doing it is bad management that needlessly demoralizes the team. My own personal expectation is that we damn well will hear from Spirit, and after a certain recovery period she'll be moving on Mars again.

My understanding was that improving the solar tilt would likely risk making it "more stuck" such that the probability of digging out after winter was through would be much lower.

That depends on what we do. Some actions would indeed risk embedding Spirit permanently; we're not going to do those if we can avoid it.

The most severe such action would be to bury the right front (RF) wheel. For better or worse, this would likely require the RF drive actuator to be significantly more cooperative than it has been. That's the wheel that died two years into Spirit's surface mission, and we tried to restart it during extrication. To our surprise, we've seen a little bit of life in it, but not so much that it can bury itself. So we probably couldn't do that even if we wanted to.

Instead, we'll probably focus mostly on arcing Spirit around so that her own structure (camera mast and high-gain antenna) casts fewer shadows on the deck, then maximize our wheelie on one side and flatten it on the other side in such a way as to aim the solar panels more to the north. The first part of this (arcing around) is what we'd be doing for extrication anyway, and the second part might reduce our extrication chances slightly but not too much. Only then, if our northerly tilt is still insufficient and we think we can materially improve it, will we take actions that could severely reduce the odds of eventual extrication. But it's not likely to come to that, if only because there's not a whole lot more we could do, period.