Software Error Likely Killed MGS Spacecraft

Aglassis writes "NASA investigators have determined that a software update performed in June of 2006 may have doomed the 10-year-old spacecraft. Apparently the software error caused the solar arrays to drive against a mechanical stop which then forced the spacecraft into safe mode. Unfortunately, after that the spacecraft's radiator was pointed at the sun which overheated the battery and destroyed it. Contact was lost with the Mars Global Surveyor spacecraft in November 2006. NASA will form an internal review board to determine formally the cause of the loss of the spacecraft and what remedial actions are needed for future missions."

Comments

Is this a sign?

[Billosaur]

Some expert is always trumpeting the fact that "Johnny can't program," to which many of us roll our eyes and go back to coding. But could this be a sign that the quality of the help NASA is hiring is such that these kinds of mistakes are now rampant? I mean, this could have been avoided if the code had been tested out on a full-scale mock-up of the machine, to verify that it did what it was supposed to do, before ever sending the commands to the actual machine. If anything, it's a QA failure.

Re:Is this a sign?

[benevixit]

In all fairness, writing code for a spacecraft is a lot harder than most of our Earthbound coding projects. These are custom-built machines running one-of-a-kind hardware; one can simulate components independently but it's very difficult to figure out how the hardware is going to behave up there in the vacuum. For example, consider the one function of maintaining orientation. Most spacecraft use telescopes that look for star reference points. They look for particular star configurations and use microthrusters or gyroscopes to adjust their orientation. Imagine what it would take to simulate this: a zero-gravity vacuum with a realistic star-field at focus=infinity. Any laboratory mock up is going to cost a lot more than launching a new spacecraft. And that's just one subsystem. Software upgrades at NASA go through a really rigorous quality control regimen, often requiring programmers to justify _individual_lines_ of their code to a review committee. Even then they usually won't patch noncritical bugs until the primary mission is completed. I think your point is a good one. And the key lesson is not that NASA QA sucks, it's that programming for spacecraft is _tough_. I know they are constantly investigating new ways (like more standardization, code re-use, and formal verification procedures) of improving software reliability.

Re:Should have used Gentoo!!

[zootm]

No sandbox can avoid the fact that one test was missing.

Re:YACCS -Yet Another Computer Corkup in Space

[spun]

In other disciplines, the engineers ARE math guys. Face it, compared to other engineering types, software engineers and programmers are SLOPPY. This is because engineering has thousands of years worth of spectacular cork-ups with enormous death tolls to look back on, and engineering students are (I'm guessing, IANAE) shown horrific, traffic-safetyesque movies like Blood on the Protractor, Slide Rule Massacre, and London Bridge is Falling Down, Killing Litle Johnny's Entire Family.

Maybe we CS types need our own safety movies, perhaps When Buffers Attack!, Threads: Your Parallel Friends or Quagmires of Debugging DOOM?, or maybe Metric or Imperial: You Mean there's a Difference? Or maybe we need to recognize that many of us have the same awesome responsibility that other engineers do of protecting human lives from the consequences of our mistakes. I'm told that this point is hammered home in engineering schools, why not in CS departments?

Re:What is Microsoft wrote it?

[edremy]

Actually, they buy their OS's off the shelf. (VxWorks for the rovers, for example)

That said, you could get software written to this level of perfection if you wanted. It's easy- follow the space shuttle's team's example. You have a stable team of mature developers who work reasonable hours. You test the hell out of the software to the point a single bug in a test is reason to redo the software. You run the software on four identical computers and make sure they all agree.

Then you hire another entire team to write code that does the same thing, but otherwise has no contact with the first team. That software runs on a fifth computer that takes over if something happens to the other four.

Willing to pay for that?

Re:YACCS -Yet Another Computer Corkup in Space

[Mayhem178]

For the uninformed, QA = Quality Assurance. A must-have for any self-respecting software model.

NASA has got it rough, has since the mid 70s. Their wildest successes are regarded as routine and hardly noticed by the public eye. Their failures, on the other hand, are spun to be the worst disasters in human history. Granted, when shuttles explode and people die, it's reasonable that the public be concerned. But it seems to me that for every 20 great things that NASA accomplishes, the media picks 1 failure (and sometimes blows that failure out of proportion) to rile the masses into a furious frenzy calling for the dissolution of NASA.