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I work on spacecraft flight software and I was never worried about this lol The worst that could have happened is that the spacecraft would have kept the dish
by Shawnj2 3y ago
I work on spacecraft flight software and I was never worried about this lol
The worst that could have happened is that the spacecraft would have kept the dish in the wrong position until October, at which point it would have re established contact. This isn’t even the last time the Voyager program has had similar outages, IIRC they had to shut down the dish for maintenance for several months and when they re established contact the spacecraft was fine. They should review their MOPS procedures so this doesn’t happen again (it’s generally standard practice to run commands against a simulated version of the spacecraft in a similar operating condition or a replica to make sure it won’t do something destructive) but from the first time I saw the headline for this my first thought was “lmao” and I was never really worried this would cause lasting problems for the spacecraft.
- throwbadubadu 3y agoIm already always much afraid when I have to remotely reboot a workstation and delighted being able to ssh into it again soon later, though the worst case here is not as bad as with this most far away remote machine, thus amazed by your confidence and calmness ;)
- Shawnj2 3y agoThe software is much simpler on Voyager so there’s not a lot to go wrong and there are a shitload of failsafes that have to go wrong before the vehicle stops working. For example on some stuff I’ve worked on and the Mars rovers there are multiple boot chips per flight computer and multiple flight computers per vehicle, and even if both are dead you can do some basic tasks just using a micro controller on the radio.
- ungamedplayer 3y agoThat is extremely cool. I'd love to have a walk though if how this works.
- Shawnj2 3y agoI agree, I linked some stuff in my response to the other comment
- barbazoo 3y agoI can't even imagine how much testing this must have gone through. Is there by any chance literature you'd recommend about this kind of tech? Maybe more on the lighter side?
- Shawnj2 3y agoOne interesting read from a purely software side is the JPL C standards, which are an extension of software standards for things like Mars rovers that cannot not work. There’s a summary on page 4 if you don’t want to read the whole thing https://yurichev.com/mirrors/C/JPL_Coding_Standard_C.pdf https://yurichev.com/mirrors/C/JPL_Coding_Standard_C.pdf Here’s a good article specific to Voyager https://www.allaboutcircuits.com/news/voyager-mission-anniversary-computers-command-data-attitude-control/ https://www.allaboutcircuits.com/news/voyager-mission-annive... I can’t find it but there was a slide deck online for Curiosity with an explanation of all the stuff I was talking about above
- NooneAtAll3 3y ago> IIRC they had to shut down the dish for maintenance in case anyone got confused like me - receiver dish _on Earth_ was shut down
- TrainedMonkey 3y agoThings worked out this time, but the cavalier attitude is dangerous. I also work on spacecraft flight software and this kind of contingency is the one you should exercise only in sims. Voyagers are unique hardware that you can't ever service - the correct risk posture here is don't. Some of the risks involved are - we don't have a good model of the flying hardware. The telemetry is extremely limited and engineers who made / understand it are scarce. Current situation of messing up commands is one of the consequences of that. There is a number of faults that are isolated and recovered via software workarounds, any kind of reset could default you in a non functional configuration. This is aging hardware that is slowly deteriorating, severed comms stop your ability to react to the events. The overall risk of permanent contact loss was probably low, but due to all the unknowns the error bars are quite high.
- Shawnj2 3y agoYep they should definitely review their procedures so this doesn’t happen again