Software on the Space Shuttle comment?

December 11, 2010 5:08 PM

Can you help me find this comment that described how software for the Space Shuttle is written?

Not sure when it was, but I remember it describing how the software is written in a general way, something like "it's written by two different teams, then cross checked to ensure its correct". I think that's how the comment started, can't remember the rest of it, other than it was fascinating. I realize this description may not be factually correct and directly contrasts with a comment I found that's linked to below. I'm just telling what you I remember in hopes that it rings someone's bell.

I did a search on mefi for "space shuttle software" and found this comment which tells of the actual group of people who write the software and their process of doing so, but it's not the comment I'm thinking of.

Is this ringing any bells for anyone? I'm almost 100% sure it was a comment, not a post.

posted by nomadicink to Feature Requests at 5:08 PM (19 comments total)

Sorry, all MeTa posts this month are required to have a higher dose of crazy. Maybe try again after New Years?
posted by auto-correct at 5:15 PM on December 11, 2010 [1 favorite]

I'm serious here, can we please not drag other stuff into this query? Thank you.
posted by nomadicink at 5:16 PM on December 11, 2010 [6 favorites]

fff mentions it in passing:

I suggest you research it yourself. If you go to Digg you'll find plenty of stories about Intel's latest CPU and the bugs in it; if you go to NASA you can learn how they always run identical hardware/software systems in triplicate, and have a watchdog program confirming that the results match; if you start reading up about functional versus dynamic programming languages, you'll learn a bit more; also check into the effect of radiation on memory and cache, and see if you can find any languages that claim to be 100% proven-correct.

posted by zamboni at 5:17 PM on December 11, 2010

There's also this (cite)?

This software never crashes. It never needs to be re-booted. This software is bug-free. It is perfect, as perfect as human beings have achieved. Consider these stats : the last three versions of the program -- each 420,000 lines long-had just one error each. The last 11 versions of this software had a total of 17 errors. Commercial programs of equivalent complexity would have 5,000 errors.

This software is the work of 260 women and men based in an anonymous office building across the street from the Johnson Space Center in Clear Lake, Texas, southeast of Houston. They work for the "on-board shuttle group," a branch of Lockheed Martin Corps space mission systems division, and their prowess is world renowned: the shuttle software group is one of just four outfits in the world to win the coveted Level 5 ranking of the federal governments Software Engineering Institute (SEI) a measure of the sophistication and reliability of the way they do their work. In fact, the SEI based it standards in part from watching the on-board shuttle group do its work.

The group writes software this good because that's how good it has to be. Every time it fires up the shuttle, their software is controlling a $4 billion piece of equipment, the lives of a half-dozen astronauts, and the dreams of the nation. Even the smallest error in space can have enormous consequences: the orbiting space shuttle travels at 17,500 miles per hour; a bug that causes a timing problem of just two-thirds of a second puts the space shuttle three miles off course.

NASA knows how good the software has to be. Before every flight, Ted Keller, the senior technical manager of the on-board shuttle group, flies to Florida where he signs a document certifying that the software will not endanger the shuttle. If Keller can't go, a formal line of succession dictates who can sign in his place...

posted by yaymukund at 5:22 PM on December 11, 2010 [12 favorites]

Sorry! Reading comprehension fail
posted by yaymukund at 5:24 PM on December 11, 2010

Thanks doublehappy, but those aren't it. Doing searchs for "apollo software" isn't hitting either, dammit.
posted by nomadicink at 5:42 PM on December 11, 2010

The source of the comment (which I can't find either) is likely either They Write the Right Stuff or Personal observations on the reliability of the Shuttle by Dick Feynman.
posted by Skorgu at 6:09 PM on December 11, 2010 [2 favorites]

We used to have a low-error real-time program in charge of a hugely expensive (relative to our budget) piece of equipment. Then they "upgraded" it and it completely sucks. Now they are writing a third version in Java.

Each version is an improvement on its successor.
posted by DU at 6:36 PM on December 11, 2010

Yeah, I too immediately thought of the "They Write The Right Stuff" article, which was so good I forwarded it to myself at work so it could be ignored by the development team.
posted by synaesthetichaze at 7:04 PM on December 11, 2010 [3 favorites]

this is an awesome metatalk.
posted by nadawi at 11:51 PM on December 11, 2010

This *is* an awesome Metatalk.
posted by Jofus at 12:03 AM on December 12, 2010

Doing a search for "space shuttle team" didn't find it, but I did come across this poster illustrating 50 years of space exploration, a zoomable picture of space and the Orion nebula, so yay.

Santa, all I want for Christmas is that comment and a spaceship.
posted by nomadicink at 5:30 AM on December 12, 2010 [1 favorite]

Here's something from NASA describing the process of developing software for Apollo. Again, this is not quite what you're looking for, but still interesting.
posted by sciencegeek at 7:02 AM on December 12, 2010

That's cool and thanks, but I really am looking for a comment I believe is on Metafilter. Damn old age.
posted by nomadicink at 7:31 AM on December 12, 2010

Describe in detail how it made you feel. Perhaps we can reverse-engineer it.
posted by Jofus at 11:24 AM on December 12, 2010

I'm not sure about the comment, but it sounds very much like it could have been a summary (or even a direct quote) from Richard Feynman's memoirs regarding the investigations into the Challenger disaster. He was extremely impressed with the way the software was developed and went out of his way to make sure his readers would be as well.
posted by Kid Charlemagne at 12:19 PM on December 12, 2010 [1 favorite]

While "They Write the Right Stuff" is probably what you're looking for, Richard P. Gabriel's Lessons From The Science Of Nothing At All provides additional context and perspective.
posted by dws at 3:40 PM on December 12, 2010

Bummer, searching for "Feynman space shuttle software" didn't bring up any comments.
posted by nomadicink at 3:47 PM on December 12, 2010

Here is (I think) the original quote. May help to locate the mefi comment.

The software is checked very carefully in a bottom-up fashion. First, each new line of code is checked, then sections of code or modules with special functions are verified. The scope is increased step by step until the new changes are incorporated into a complete system and checked. This complete output is considered the final product, newly released. But completely independently there is an independent verification group, that takes an adversary attitude to the software development group, and tests and verifies the software as if it were a customer of the delivered product.

though not necessarily the original source.
posted by shoesfullofdust at 7:22 PM on December 23, 2010