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47-year-old Voyager 1 fired up thrusters it hasn't used in decades

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Re: 47-year-old Voyager 1 fired up thrusters it hasn't used in decades

#21

Post by virtue3 »

tannhaeuser wrote: post #18
yashg wrote: post #6

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.

> 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 tida…

Not as old as you might think: https://www.jpl.nasa.gov/images/pia26275-voyager-team-celebr...

Re: 47-year-old Voyager 1 fired up thrusters it hasn't used in decades

#22

Post by CogitoCogito »

bigiain wrote: post #10
yashg wrote: post #6

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.

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…

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!

Re: 47-year-old Voyager 1 fired up thrusters it hasn't used in decades

#23

Post by bigiain »

CogitoCogito wrote: post #22
bigiain wrote: post #10

Earlier quoted context omitted.

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…

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!

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...

Re: 47-year-old Voyager 1 fired up thrusters it hasn't used in decades

#24

Post by piokoch »

You can agree with me or not, but Voyager 1/2 is a top technological achievement of the humankind. A piece of hardware so good that it survived working correctly 47 years in a hostile environment, driven by a computer with the power of modern car key. Amazing.

Re: 47-year-old Voyager 1 fired up thrusters it hasn't used in decades

#25

Post by quesera »

yashg wrote: post #6

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.

> 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.

Re: 47-year-old Voyager 1 fired up thrusters it hasn't used in decades

#26

Post by [deleted] »

akira2501 wrote: post #17
yashg wrote: post #6

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.

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 spacec…

[deleted]

Re: 47-year-old Voyager 1 fired up thrusters it hasn't used in decades

#27

Post by _joel »

quesera wrote: post #25
yashg wrote: post #6

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.

> 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…

https://space.stackexchange.com/questions/3093/how-does-the-... :)

Re: 47-year-old Voyager 1 fired up thrusters it hasn't used in decades

#30

Post by Intralexical »

quesera wrote: post #25
yashg wrote: post #6

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.

> 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…

> 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

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