'Extreme Programming' Controls Phoenix Mars Lander

pbd points out a story discussing the challenges faced by NASA engineers in designing the code sent to operate the Phoenix Mars Lander. Quoting Computerworld: "On Wednesday, engineers sent up the code to run an actual analysis, but a satellite orbiting Mars, which transfers the data down to the Lander, was offline. Robinson explained that the satellite had been hit with radiation, knocking it into safe mode. 'Space is a harsh environment, and sometimes they just go into safe mode,' he noted. 'It's a minor problem. [The satellite] aborts whatever it was doing and waits for future commanding.' Engineers successfully resent the code on Thursday."

Comments

That's coolness

[zappepcs]

Not sure about others, but designing software and systems (software & hardware) that understand the data they are using, and when conditions are not right AND know how to go to safe mode rather than just fall apart is awesomeness in physical form.

Then just considering it a minor problem is an even higher form of awesomeness :)

As a hobby I build small robotic creations. I can tell you that working with limited resources, and having to deal with the completely unexpected is just brain damage for the fun of it. Testing your new code on the same hardware you've had for months and thinking "I really did not know that you could bend this metal piece with so little force" or "why the hell is it doing that" and find out that you missed a decimal point on force calculations or a typo leaves you reacting with subroutine x instead of y.

Those engineers have to be fscking proud of their work. I know I would be. Some days I look at code I've had running 24/7 for several years and am amazed, not just at myself, but that I managed to find the bugs and fix the "I didn't know that would happen" issues. It's a lot of type and bounds checking to be certain, but something always creeps in.

I say they should be proud. The Mars missions have been nothing short of exemplary awesomeness. When they figure out the failure they did have, I'm certain that the absolute goodness they built into it will help reveal totally amazing discoveries about why there was a failure. Nothing simple like metric conversions, or wrong alloy for the screws.

Makes me want to work with them. :)

Re:That's coolness

[zappepcs]

Actually, considering it a minor problem is not irresponsible risk. When you are that cock sure of the equipment you designed that you can think of it as a minor problem when space radiation knocks your system into safe mode for a bit, you have awesome mad design skills, not risk taking behaviors.

Yes, they used tax payers' money, and I'm pretty glad that I helped contribute in some way. Exploring our solar system and beyond with instrumentation is an absolutely needed step to find more space for all the humans on this planet. Not sure if you have noticed, but there are a few things we are running out of here despite China's one child rule.... room, food, fuel, and some other less dramatic things. Mother nature has a way of balancing things, so she'll kill a lot of us off. If we want to continue growing, expanding, space is the only viable option with current trends and technology. Improving the technology we command and the information that we have is the only way to viable improvements. The space exploration programs aim to do this in very calculated ways, very methodical steps to discover new information on a cost per answer type basis.

It is NOT irresponsible. There are a lot of irresponsible uses of tax payers' money, but trying to expand human knowledge and capabilities is not.

Re:That's coolness

[satoshi1]

Linux may not be ready for the desktop, but it is ready for the surface of Mars.
-Me

You know, I am actually cool with that. A stable operating system running a mission critical device thousands of miles away is important, everyone who has contributed to the Linux kernel in some way should be proud that their work is enabling us to learn amazing new things about our red neighbor. I think it says a lot that Linux was chosen over some internallly developed OS.

Re:That's coolness

[Tolkien]

Better him than the gov't, odds are they'll claim ownership, despite not having the right to do so.

Embedded programming is hard!

[compumike]

Sure, there's complicated software systems, but when something has to deal with hardware too, there's just a lot more to think about in every action. That's why engineers make abstractions -- enough to keep their part of a particular project in their head.

But shouldn't the "safe mode" limits be independent of the particular operation as much as possible? In software engineering, the people writing test cases are often not the same as the people developing the code, and for the reason that they want to match both to the spec, not to each other.

--
Hey code monkey... want to learn electronics?

!extreme programming

[religious freak]

Aside from having a strong general dislike for anything 'extreme', this is wrong because this is obviously (at least from what I saw) NOT extreme programming, it's programming for harsh environments (no not Windows :).

Crappy title.

Re:Why do they have to do this much coding?

[Tablizer]

I agree, there's something odd about using C to "program" daily instrument movements. They just need coordinate tables, not C programming. If there are conditionals, they cannot be complex enough to justify C, can they? The rovers didn't have very many conditionals for their sequences based on what I read. If something is not as expected, they usually have the rover stop and wait for Earth confirmation, NOT make the robot select contingency options (unless automated driving is on, but it still has low tolerances before going into wait-mode). I suspect the article is confusing the work of two different teams: the "operating" software developers and the instrument sequencers. Some journalists don't know C from a horse shoe......oh wait.

Re:Call me a pragmatist...

[justinlee37]

I don't think the actual article has to do with the XP methodology, though, the headline writer was just too dumb to avoid referencing XP 'cause he didn't know about it.

Re:Some other interesting points about that articl

[Lumpy]

Exactly, I get a kick out of guys that second guess programmers that are so more advanced than they are that they can only HOPE to aspire to be as good as the guys at NASA.

That and From my experience, less than 10% of all programmers have ever done anything embedded or robotics wise. The rules change when you are writing software for engine management, robots, or space probes, than when you are writing a new consumer toy app or spreadsheet program.

Re:Why do they have to do this much coding?

[dodobh]

That close to the metal, with the limited memory space and CPU power? C is probably the highest level language which works.