Spacecraft Flight Computers
Discussions center on computers and software in historical NASA missions like Apollo and Voyager, as well as modern SpaceX systems, focusing on reliability, redundancy, in-flight reprogramming, testing, and conservative engineering practices.
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Upvote for mentioning the Apollo Guidance Computer!
Not true, the voyagers can be in-flight reprogrammed: https://history.nasa.gov/computers/Ch6-2.html
There has been several references that SpaceX "fly" their Falcon 9 computer systems to test for bugs like this. The idea being that as far as the computer is concerned, it is a real flight and should act accordingly. Most of the problems to date, have been related to a mechanical problem. During the first docking, there was a minor issue with the sensor "field of vision" but this was fixed.The point is that SpaceX procedures seem to be able to prevent similar software bugs in the Ariane 5 fro
I think it is likely. I was under the impression that space programs try to keep identical subsystems on Earth so they can use them to debug in-mission issues. Hard to attach a JTAG debugger when your device under test is 34 lighthours away! =)
You think a manned mission obviates software?
There isn’t a simulator or digital twin for voyager. It has a bespoke processor made with 74* style logic. One guy will puts together a command and they will have a review where the other engineers will try and independently verify it. Then they copy and paste the command somewhere to “run it”. It happened, fairly recently, that the command had a typo that was caught in review, but the “wrong” pre-review command was used and the attitude became off by so much that they lost contact. It was onl
Didn't the Apollo flight computer crash/have to be restarted during the landing phase?
Not Voyager but here’s code from the Apollo program: https://github.com/chrislgarry/Apollo-11/
Perhaps some code running on the CPU of one of the Voyager spacecrafts?
That seems extremely unlikely. Astronaut's time is mapped to the minute, no one is going to run important code without it being extensively tested first (imagine the potential for catastrophe), and the cost of an astronaut's time per minute is astronomical (pun intended!). Why wouldn't you have a professional write it on the ground, test it, and upload it?