7 ms·

A radio signal takes more than 22 hours to reach Voyager 1. And it would take the same to get a response back. Incredible. And imagine the patience needed to se

by yashg 2y ago

A radio signal takes more than 22 hours to reach Voyager 1. And it would take the same to get a response back. Incredible. And imagine the patience needed to send commands and wait for the outcome on the part of the engineering team. You can't afford to send a wrong command and have the luxury of undo. Also, I wonder how many generations of engineers must have worked on the project by now.

b112 2y ago
You can't afford to send a wrong command and have the luxury of undo. Indeed. We used to do this all the time. Cars without OTA updates, games and software shipped on disk or floppy or cd, all very make or break.
- DaoVeles 2y ago
  An aside but this is why I was blown away by Mario Odyssey on the Switch. While it did get patches to add a few new games modes and bonuses, there was nothing done to fix anything broken with the title because there wasn't anything. If you buy a physical copy from the last few years, there is no additional patch to download. They had all the issues sorted out before release, very rare nowadays.
  - gambiting 2y ago
    Oh it definitely has bugs and glitches - tonnes of them in fact. It's just that Nintendo chooses not to fix them(not that they should, 90% of them are basically people actively trying to break stuff, although some I can see how you could do it accidentally). https://www.youtube.com/watch?v=gWYmV0bs15w https://www.youtube.com/watch?v=gWYmV0bs15w https://www.mariowiki.com/List_of_Super_Mario_Odyssey_glitches https://www.mariowiki.com/List_of_Super_Mario_Odyssey_glitch... And issues have been fixed in patches too, like the first glitch on that list that would lock your camera so you couldn't turn it - that was fixed in a patch. "If Mario performs a Cap Throw at Talkatoo and talks to him at the same time, the camera will lock into place.[...] As of the February 21, 2018 update, this glitch is fixed" But there are situations that will literally crash the game to the OS too: "In the Bowser's Moon Wedding objective, if Mario falls into the lava just as he is about to capture Bowser, the game immediately crashes."
    - DaoVeles 2y ago
      That's for that recap! (Pun intended!). I should have been more specific by being more vague. The game didn't need to be patched for the vast majority of its common use. I would be surprised if there are any games with a degree of freedom that you couldn't crash if you did just the right thing. But for 99.99% of players, they will never come across these things. What I should have said is that if left un-patched, most people would never hit a problem. But I really appreciate the heads up about all the glitches people are using, very cool.
- Rinzler89 2y ago
  That's when QA and SW testing was still a job, before the age of cargo cults like Agile, Scrum and SV's "move fast and break things" took over.
- XorNot 2y ago
  To be fair OTA updates aren't "low risk" - the trick is that you make your OTA system rock-solid so a failure results in a device you can still OTA too.
bigiain 2y ago
I suspect most people who've ever been responsible for colo-ed unix-ish servers have learned to do something like: > ufw reset | at now +5 minutes When doing "dangerous" things like updating firewall rules. I wonder if they have a way to send commands saying something like: Switch to thruster set 1, wriggle the antenna aim away and back to earth, wait 46 hours, if you do not receive "all clear" from earth switch back to thruster set 3 and re aim the antenna at earth.
- CogitoCogito 2y ago
  So obvious! But _no_ I haven't done this even though I have messed up remote servers where this would have helped. A bit embarrassed I didn't think of it myself, but thanks for the tip nonetheless!
  - bigiain 2y ago
    I also did not think of it myself, but had it shown to me by a greybeard after complaining about having messed up in exactly that way, and had to pay extortionate prices for "hands on" by someone at our colo facility...
- minkles 2y ago
  I still fuck them up after 20 years. Fortunately we have ILO / RAS cards in everything.
- Brian_K_White 2y ago
  No I just always have a serial console and a power switch which are not affected by anything I can do on that box.
akira2501 2y ago
You characterize every single piece of equipment on platform so you can do somewhat accurate simulations. The shuttle flew most of the critical phases of their missions on the ground before ever uploading the code into an actual shuttle computer. The simulation system was continuously updated with real world performance information so it's accuracy continually improves. You also have a command processor on the spacecraft side. It will have some of these characterizations present as limits on command authority. Commands sent without override that exceed these limits will be ignored, possibly cancelling the entire sequence of dependent commands. You can demand that these limits be ignored but this obviously requires you to specify it redundantly in the message set. Should anything happen your flight software is generally going to go into a recovery mode. Voyager will try this 4 times after a period of no commands triggers a watchdog. This will switch on different radios while keeping them oriented towards the Earth in a constant effort to reacquire the command signals. Should this process fail a backup flight software mode will then activate which performs basic mission functions on a continuous loop so whatever continues to operate on the spacecraft will transmit it's data automatically back to the Earth at it's highest power setting. Voyager was a continuation of some of the Viking hardware and flight systems.
- deleted 2y ago
  [deleted]
- ForHackernews 2y ago
  > You characterize every single piece of equipment on platform so you can do somewhat accurate simulations. The shuttle flew most of the critical phases of their missions on the ground before ever uploading the code into an actual shuttle computer. The simulation system was continuously updated with real world performance information so it's accuracy continually improves. This is not true of the Voyager probes: > Newer NASA missions have hardware and software simulators on the ground, where engineers can test new procedures to make sure they do no harm when they uplink commands to the real spacecraft. Due to its age, Voyager doesn't have any ground simulators, and much of the mission's original design documentation remains in paper form and hasn't been digitized. https://www.wired.com/story/nasa-repair-voyager-1-spacecraft-data/ https://www.wired.com/story/nasa-repair-voyager-1-spacecraft...
tannhaeuser 2y ago
> Also, I wonder how many generations of engineers must have worked on the project by now. Would've expected the generation raised on punch cards to be ideally suited for this kind of stunt, having learnt the hard way about the turnaround time for a bug (Donald Knuth quote about proving programs correct comes to mind), so I'd expect mission control, operators, and coders to be well in their 70s at least? Whereas tiday we hardly can write a single line if code without our AI overloads introducibg typos and not-fo-subtlr bugs.
- virtue3 2y ago
  Not as old as you might think: https://www.jpl.nasa.gov/images/pia26275-voyager-team-celebrates-engineering-data-return https://www.jpl.nasa.gov/images/pia26275-voyager-team-celebr...
  - tannhaeuser 2y ago
    With respect, most people sitting around the table on that photo sure look like 70+ don't they? Not there's anything wrong with it ...
quesera 2y ago
> A radio signal takes more than 22 hours to reach Voyager 1 Voyager has a 23 watt radio and a 14 foot parabolic dish antenna, pointed directly at Earth which is presently 15 billion miles away. The corresponding earth ground station has a 100 foot dish and transmits at thousands of watts. It's astonishing to me that Voyager knows where Earth is at all. I imagine it uses Sol as a reference? Or maybe the high powered control signal carrier? Amazing stuff.
- _joel 2y ago
  https://space.stackexchange.com/questions/3093/how-does-the-star-tracker-in-voyager-1-lock-onto-a-specific-star https://space.stackexchange.com/questions/3093/how-does-the-... :)
- Intralexical 2y ago
  > It's astonishing to me that Voyager knows where Earth is at all. Wikipedia says that the high-gain antenna has a beamwidth of 0.5° for X-band, and 2.3° for S-band. You have: tan(0.5deg/2)*2*164astronomicalunit You want: astronomicalunit * 1.4311791 So it's so far that you could almost point it straight at the sun, and have the entire orbit of the Earth in the beam. 23 watts, spread out in a cone the size of a planetary orbit. https://en.wikipedia.org/wiki/Voyager_program#Communications https://en.wikipedia.org/wiki/Voyager_program#Communications
  - quesera 2y ago
    Which correspondingly means that the received signal strength here on Earth is very low. Internet says approximately -160.48 dBm, which is one thousandth of the minimum strength that the most sensitive commercial FM radio receivers can discriminate. Hence the huge receiving dishes, and apparently one 100 foot dish alone does not collect enough energy to reconstruct the signal, so multiple are required at each Deep Space Network receiving station. And due to the rotation of the Earth, we need three DSN stations to maintain constant communication with Voyager.
    - HPsquared 2y ago

by yashg 2y ago

b112 2y ago

You can't afford to send a wrong command and have the luxury of undo. Indeed. We used to do this all the time. Cars without OTA updates, games and software shipped on disk or floppy or cd, all very make or break.

DaoVeles 2y ago
An aside but this is why I was blown away by Mario Odyssey on the Switch. While it did get patches to add a few new games modes and bonuses, there was nothing done to fix anything broken with the title because there wasn't anything. If you buy a physical copy from the last few years, there is no additional patch to download. They had all the issues sorted out before release, very rare nowadays.
- gambiting 2y ago
  Oh it definitely has bugs and glitches - tonnes of them in fact. It's just that Nintendo chooses not to fix them(not that they should, 90% of them are basically people actively trying to break stuff, although some I can see how you could do it accidentally). https://www.youtube.com/watch?v=gWYmV0bs15w https://www.youtube.com/watch?v=gWYmV0bs15w https://www.mariowiki.com/List_of_Super_Mario_Odyssey_glitches https://www.mariowiki.com/List_of_Super_Mario_Odyssey_glitch... And issues have been fixed in patches too, like the first glitch on that list that would lock your camera so you couldn't turn it - that was fixed in a patch. "If Mario performs a Cap Throw at Talkatoo and talks to him at the same time, the camera will lock into place.[...] As of the February 21, 2018 update, this glitch is fixed" But there are situations that will literally crash the game to the OS too: "In the Bowser's Moon Wedding objective, if Mario falls into the lava just as he is about to capture Bowser, the game immediately crashes."
  - DaoVeles 2y ago
    That's for that recap! (Pun intended!). I should have been more specific by being more vague. The game didn't need to be patched for the vast majority of its common use. I would be surprised if there are any games with a degree of freedom that you couldn't crash if you did just the right thing. But for 99.99% of players, they will never come across these things. What I should have said is that if left un-patched, most people would never hit a problem. But I really appreciate the heads up about all the glitches people are using, very cool.
Rinzler89 2y ago
That's when QA and SW testing was still a job, before the age of cargo cults like Agile, Scrum and SV's "move fast and break things" took over.
XorNot 2y ago
To be fair OTA updates aren't "low risk" - the trick is that you make your OTA system rock-solid so a failure results in a device you can still OTA too.

bigiain 2y ago

I suspect most people who've ever been responsible for colo-ed unix-ish servers have learned to do something like: > ufw reset | at now +5 minutes When doing "dangerous" things like updating firewall rules. I wonder if they have a way to send commands saying something like: Switch to thruster set 1, wriggle the antenna aim away and back to earth, wait 46 hours, if you do not receive "all clear" from earth switch back to thruster set 3 and re aim the antenna at earth.

CogitoCogito 2y ago
So obvious! But _no_ I haven't done this even though I have messed up remote servers where this would have helped. A bit embarrassed I didn't think of it myself, but thanks for the tip nonetheless!
- bigiain 2y ago
  I also did not think of it myself, but had it shown to me by a greybeard after complaining about having messed up in exactly that way, and had to pay extortionate prices for "hands on" by someone at our colo facility...
minkles 2y ago
I still fuck them up after 20 years. Fortunately we have ILO / RAS cards in everything.
Brian_K_White 2y ago
No I just always have a serial console and a power switch which are not affected by anything I can do on that box.

akira2501 2y ago

You characterize every single piece of equipment on platform so you can do somewhat accurate simulations. The shuttle flew most of the critical phases of their missions on the ground before ever uploading the code into an actual shuttle computer. The simulation system was continuously updated with real world performance information so it's accuracy continually improves. You also have a command processor on the spacecraft side. It will have some of these characterizations present as limits on command authority. Commands sent without override that exceed these limits will be ignored, possibly cancelling the entire sequence of dependent commands. You can demand that these limits be ignored but this obviously requires you to specify it redundantly in the message set. Should anything happen your flight software is generally going to go into a recovery mode. Voyager will try this 4 times after a period of no commands triggers a watchdog. This will switch on different radios while keeping them oriented towards the Earth in a constant effort to reacquire the command signals. Should this process fail a backup flight software mode will then activate which performs basic mission functions on a continuous loop so whatever continues to operate on the spacecraft will transmit it's data automatically back to the Earth at it's highest power setting. Voyager was a continuation of some of the Viking hardware and flight systems.

deleted 2y ago
[deleted]
ForHackernews 2y ago
> You characterize every single piece of equipment on platform so you can do somewhat accurate simulations. The shuttle flew most of the critical phases of their missions on the ground before ever uploading the code into an actual shuttle computer. The simulation system was continuously updated with real world performance information so it's accuracy continually improves. This is not true of the Voyager probes: > Newer NASA missions have hardware and software simulators on the ground, where engineers can test new procedures to make sure they do no harm when they uplink commands to the real spacecraft. Due to its age, Voyager doesn't have any ground simulators, and much of the mission's original design documentation remains in paper form and hasn't been digitized. https://www.wired.com/story/nasa-repair-voyager-1-spacecraft-data/ https://www.wired.com/story/nasa-repair-voyager-1-spacecraft...

tannhaeuser 2y ago

> Also, I wonder how many generations of engineers must have worked on the project by now. Would've expected the generation raised on punch cards to be ideally suited for this kind of stunt, having learnt the hard way about the turnaround time for a bug (Donald Knuth quote about proving programs correct comes to mind), so I'd expect mission control, operators, and coders to be well in their 70s at least? Whereas tiday we hardly can write a single line if code without our AI overloads introducibg typos and not-fo-subtlr bugs.

virtue3 2y ago
Not as old as you might think: https://www.jpl.nasa.gov/images/pia26275-voyager-team-celebrates-engineering-data-return https://www.jpl.nasa.gov/images/pia26275-voyager-team-celebr...
- tannhaeuser 2y ago
  With respect, most people sitting around the table on that photo sure look like 70+ don't they? Not there's anything wrong with it ...

quesera 2y ago

> A radio signal takes more than 22 hours to reach Voyager 1 Voyager has a 23 watt radio and a 14 foot parabolic dish antenna, pointed directly at Earth which is presently 15 billion miles away. The corresponding earth ground station has a 100 foot dish and transmits at thousands of watts. It's astonishing to me that Voyager knows where Earth is at all. I imagine it uses Sol as a reference? Or maybe the high powered control signal carrier? Amazing stuff.

_joel 2y ago
https://space.stackexchange.com/questions/3093/how-does-the-star-tracker-in-voyager-1-lock-onto-a-specific-star https://space.stackexchange.com/questions/3093/how-does-the-... :)
Intralexical 2y ago
> It's astonishing to me that Voyager knows where Earth is at all. Wikipedia says that the high-gain antenna has a beamwidth of 0.5° for X-band, and 2.3° for S-band. You have: tan(0.5deg/2)*2*164astronomicalunit You want: astronomicalunit * 1.4311791 So it's so far that you could almost point it straight at the sun, and have the entire orbit of the Earth in the beam. 23 watts, spread out in a cone the size of a planetary orbit. https://en.wikipedia.org/wiki/Voyager_program#Communications https://en.wikipedia.org/wiki/Voyager_program#Communications
- quesera 2y ago
  Which correspondingly means that the received signal strength here on Earth is very low. Internet says approximately -160.48 dBm, which is one thousandth of the minimum strength that the most sensitive commercial FM radio receivers can discriminate. Hence the huge receiving dishes, and apparently one 100 foot dish alone does not collect enough energy to reconstruct the signal, so multiple are required at each Deep Space Network receiving station. And due to the rotation of the Earth, we need three DSN stations to maintain constant communication with Voyager.
  - HPsquared 2y ago