What really happened to the software on the Mars Pathfinder spacecraft? • Hacker News Board

Re: What really happened to the software on the Mars Pathfinder spacecraft?

#31

Post by outworlder » Fri, Jul 05, 2013, 1:05 PM UTC

DigitalJack wrote: post #17

kamaal wrote: post #12

Earlier quoted context omitted.

It was the same thought I had too. I remember reading it in a article some time back. Software for this sort of systems isn't written like we do. Come to office, fire up IDE and code. Rather by and large software is first written on paper and the possible side effects and correctness is first verified thoroughly. I know of a embedded programmer from 80's/90's era. He has done embedded programming both in assembly and…

That fricken web browser. I had to resort to sticking hacker news and a few others in my hosts file pointing back to 127.0.0.1. (On xp)

Turn on the noprocrast flag.

Re: What really happened to the software on the Mars Pathfinder spacecraft?

#32

Post by javert » Fri, Jul 05, 2013, 4:45 PM UTC

alemhnan wrote: post #27

javert wrote: post #26

Earlier quoted context omitted.

> Prove its correctness That's probably an overstatement :P

well, sure it is right now because we are not able to do so yet. But there is a lot of research in computer science trying to do made that statement less over! :)

Yeah, but AFAIK they have been researching that topic for like 30 years with very little progress overall.

Re: What really happened to the software on the Mars Pathfinder spacecraft?

#33

Post by dschiptsov » Sat, Jul 06, 2013, 3:50 AM UTC

lisper wrote: post #19

dandrews wrote: post #10

Earlier quoted context omitted.

You're likely thinking of this essay: http://www.flownet.com/gat/jpl-lisp.html

Or this: http://www.youtube.com/watch?v=_gZK0tW8EhQ

Thank you for this. This is almost a meta-story, how "politicians"/"managers" are always ruining everything that is good and true, meaning of which they genetically incapable to grasp.

Re: What really happened to the software on the Mars Pathfinder spacecraft?

#34

Post by mturmon » Sat, Jul 06, 2013, 7:05 AM UTC

nknighthb wrote: post #8

gizmo686 wrote: post #6

Earlier quoted context omitted.

>\Sounds like the sort of programmers who are inclined to blame "cosmic rays" for odd behavior that they don't understand. In fairness, they go out of their way to harden they computers against cosmic rays. I am sure that they make a decision about what an acceptable amount of cosmic ray induced error is, and design the system knowing that it will happen. Having said that, I agree that having unexplained problems on…

In further fairness, Pathfinder's name was also its job description. It was built on a relative shoestring and in a way, fulfilled its most important function the moment Sojourner rolled onto Martian soil. It was basically a combination prototype/advance scout.

Absolutely correct. More context: Pathfinder was done during the Goldin era of better, faster, cheaper.

Re: What really happened to the software on the Mars Pathfinder spacecraft?

#35

Post by mturmon » Sat, Jul 06, 2013, 7:10 AM UTC

kotnik wrote: post #28

For a (much) more detailed story, go here: https://www.cs.duke.edu/~carla/mars.html

Thanks for this. It gets in to details about how e fix was deployed and says more about why it was not caught during testing.

Re: What really happened to the software on the Mars Pathfinder spacecraft?

#36

Post by DigitalJack » Sat, Jul 06, 2013, 10:36 AM UTC

outworlder wrote: post #31

DigitalJack wrote: post #17

Earlier quoted context omitted.

That fricken web browser. I had to resort to sticking hacker news and a few others in my hosts file pointing back to 127.0.0.1. (On xp)

Turn on the noprocrast flag.

The problem is that it is too easy to turn back off. Editing the hosts file on xp is sort of a pain, so it works for overcoming the impulsive browsing.