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If anybody else is interested in the topic, the seminal work on software development at NASA is the Fast Company feature from 1996, "They write the right stuff"

by nikcub 14y ago

If anybody else is interested in the topic, the seminal work on software development at NASA is the Fast Company feature from 1996, "They write the right stuff": http://www.fastcompany.com/node/28121/print?donttaseme http://www.fastcompany.com/node/28121/print?donttaseme

sigkill 14y ago
I've read that over a dozen times by now and I'm still fascinated by it.
smcl 14y ago
Why the "donttaseme" in the query string?
- qxcv 14y ago
  $ vimdiff <(curl http://www.fastcompany.com/node/28121/print?donttaseme http://www.fastcompany.com/node/28121/print?donttaseme) <(curl http://www.fastcompany.com/node/28121/print http://www.fastcompany.com/node/28121/print) Aesthetics, perhaps?
- nikcub 14y ago
  I had it bookmarked like that, my guess is that it was a re-submission and somebody added that tag in order to make the URL unique
fidotron 14y ago
Worth saying that doesn't apply outside manned missions. They notoriously crashed a probe into Mars thanks to erroneous imperial to metric unit conversion. EDIT: also the VxWorks fan stuff here is a bit odd, given the other notorious error involved setting the task priorities so that the probe spent the whole time checking the weather, but never phoned home. They were just lucky they shipped the thing in debug mode and reprogrammed it once it had landed.
- jrabone 14y ago
  That pathfinder bug was a priority inversion caused by failing to enable priority inheritance when creating mutexes, not quite as simple as setting the priorities wrong. VxWorks wasn't entirely at fault, although the priority inheritance feature was not obvious. Concurrency is hard. See http://research.microsoft.com/en-us/um/people/mbj/mars_pathfinder/mars_pathfinder.html http://research.microsoft.com/en-us/um/people/mbj/mars_pathf... for details.
  - lcargill99 14y ago
    you really, really should never write things such that task priorities must be of a certain arrangement for the thing to work properly. It's very bad form. Also, from the link "Tasks on the Pathfinder spacecraft were executed as threads with priorities that were assigned in the usual manner reflecting the relative urgency of these tasks." Yeaaaaaugh! "PRIORITIES DO NOT WORK THAT WAY!" - Morbo.
mcguire 14y ago
"Bill Pate...says the group understands the stakes: "If the software isn't perfect, some of the people we go to meetings with might die." Some days....

by nikcub 14y ago

sigkill 14y ago

I've read that over a dozen times by now and I'm still fascinated by it.

smcl 14y ago

Why the "donttaseme" in the query string?

qxcv 14y ago
$ vimdiff <(curl http://www.fastcompany.com/node/28121/print?donttaseme http://www.fastcompany.com/node/28121/print?donttaseme) <(curl http://www.fastcompany.com/node/28121/print http://www.fastcompany.com/node/28121/print) Aesthetics, perhaps?
nikcub 14y ago
I had it bookmarked like that, my guess is that it was a re-submission and somebody added that tag in order to make the URL unique

fidotron 14y ago

Worth saying that doesn't apply outside manned missions. They notoriously crashed a probe into Mars thanks to erroneous imperial to metric unit conversion. EDIT: also the VxWorks fan stuff here is a bit odd, given the other notorious error involved setting the task priorities so that the probe spent the whole time checking the weather, but never phoned home. They were just lucky they shipped the thing in debug mode and reprogrammed it once it had landed.

jrabone 14y ago
That pathfinder bug was a priority inversion caused by failing to enable priority inheritance when creating mutexes, not quite as simple as setting the priorities wrong. VxWorks wasn't entirely at fault, although the priority inheritance feature was not obvious. Concurrency is hard. See http://research.microsoft.com/en-us/um/people/mbj/mars_pathfinder/mars_pathfinder.html http://research.microsoft.com/en-us/um/people/mbj/mars_pathf... for details.
- lcargill99 14y ago
  you really, really should never write things such that task priorities must be of a certain arrangement for the thing to work properly. It's very bad form. Also, from the link "Tasks on the Pathfinder spacecraft were executed as threads with priorities that were assigned in the usual manner reflecting the relative urgency of these tasks." Yeaaaaaugh! "PRIORITIES DO NOT WORK THAT WAY!" - Morbo.

mcguire 14y ago

"Bill Pate...says the group understands the stakes: "If the software isn't perfect, some of the people we go to meetings with might die." Some days....