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.

Interestingly, all the CSIRAC history forgets to mention it was located at Chisholm Institute of Technology's Caulfield campus (now Monash) for a long time as a display of one of the earliest computers ever made. I worked there and had the keys into the display, I now wish I'd added a bit of graffiti to the mercurary delay lines.

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.

I get 70meg a second at my desk
(And the Microsoft guys we had in last month, couldn't believe you can download the Windows 7 iso, in under 5 minutes until they all did it themselves)
I guess it makes up for the crappy pay......

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!