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NASA can't figure out what's causing computer issues on the Hubble telescope

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Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#51

Post by etskinner »

fouric wrote: post #17

I know that, at different times, NASA has used Forth[1] and Lisp[2] in some of their space applications. Both of these languages offer REPLs that generally accelerate the debugging process, and while your "average" Lisp might be unsuitable for hard real-time applications (due to the presence of a garbage collector, usually without the hard real-time constraints that you can get out of garbage collectors with extreme…

> Wait, then why don't they just switch over each component in turn? The "divide and conquer" debugging strategy.

My guess would be that they want to try that method only if this debugging doesn't work. Imagine that there's an electrical issue in item 1 that fries item 2. If you switch over to item 2b, then you fry item 2b too!

This is exactly what happened with the Soviet Salyut 7 station. They tripped an over-current protection, didn't fix the root issue, and remotely turned the circuit back on. A series of electrical shorts then rendered the entire station without power, resulting in the need for one of the most daring station rescue stories of all time:

https://arstechnica.com/science/2014/09/the-little-known-sov...

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#52

Post by smileysteve »

Koshkin wrote: post #14
qzw wrote: post #7

pushes up glasses I would watch the heck out of a Twitch stream of their debugging/brainstorming sessions. I always loved the movie Apollo 13 , especially the technical troubleshooting parts.

Debugging on a computer that is down is not a very exciting process.

especially with extremely long response times.

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#53

Post by 2Gkashmiri »

i once read an article on most probably arstechnica about a nasa enthusiast who found some space probe documentation in someones garage. he goes on to actually use that to communicate with the probe and issue commands. something like the booster had emptied or leaked or something. i am not sure what exactly it was. that was a fascinating read

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#56

Post by _joel »

beerandt wrote: post #50
setug wrote: post #31

Wouldn't it be a good idea to open the source code for community inspection? Of course NASA would panic with Russia and China inspecting for "hostile" actions, but hey, if they don't know what to do, why not calling the expert reverse engineers of the world?

Idk about the payload computer, but I've got to think guidance and operation controls would have at least some remnants of legacy keyhole technology, or would expose hardware details that might still be sensitive information, even if the software was a total rewrite.

Hubble is basically a US spy satellite, pointing outwards instead of inwards. I'm sure there will be similar classes of hardware still in operation, so could be some sensitivity there.

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#58

Post by recov »

setug wrote: post #31

Wouldn't it be a good idea to open the source code for community inspection? Of course NASA would panic with Russia and China inspecting for "hostile" actions, but hey, if they don't know what to do, why not calling the expert reverse engineers of the world?

Interesting thought. I would say something like the hubble transcends politcal/governmental boundaries... although I do wonder how much if its software is used in other secretive satellites.

Re: NASA can't figure out what's causing computer issues on the Hubble telescope

#60

Post by bumby »

mikeytown2 wrote: post #35
bumby wrote: post #15

Earlier quoted context omitted.

Is there evidence of either yet? I’m not sure how you get from “potential” failure mode to “most likely”

They're trying to find the broken component; what caused the issue is usually a handful of things in space. Those are usually the top causes of component failure in that environment.

Although a relatively small part of my career, I spent some time working within the quality arm of an aerospace org. A lot more on propulsion systems, but both those and satellites are usually required to meet J-STD specs for electronic builds. After a few failure investigations, you become acutely aware of the dangers of prematurely jumping to conclusions.
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