that is amazing for something 14.5 billion miles away

It's also amazing considering it's using a computer built over 45 years ago from discrete components with only 70Kb of memory, while operating on a gradually failing thermonuclear power source. Voyager 1 also holds the world record for the longest continual operation of a computer:

https://www.guinnessworldrecords.com/world-records/635980-lo...

Wow. World record for the longest continual operation of a computer... achieved in a radiation bath.

Pretty much, although I think the RTG is mounted on a limb as far away from the other equipment as possible, but still the computer needs to be able to tolerate a decent amount of radiation. It also has an interesting redundant design where it has double the component count and can either exploit that for extra compute or redundancy in case of component failure.

I think parent comment is talking about cosmic radiation and not the one from RTG which most probably is properly shielded.

Possibly. I wonder which is the more significant source given it's distance from the Sun.

Solar particles become less of a threat, but the sun's atmosphere actually shields the solar system from some types of cosmic rays. Don't know what proportion of electronics faults stem from each, though.

It used a memory called "plated wire memory" which, like the very related core memory is very resistant to changes caused by radiation.

https://en.wikipedia.org/wiki/Plated_wire_memory

> ...the last of the project's original programmers, retired, and it was difficult to find a replacement with such in-depth knowledge of what now seem like ancient hardware and design principles

Man I would not want to be the one to brick that.

That makes me realize, it would actually be an incredibly fun job to be in the team that manages the simulation/emulation stack that people tinker with to learn about this thing.

Going on a lot of presumption here (and a bit of optimism...), I would presume "don't brick it" is backed up by an appropriate level of funding to cover the training people receive before they get to touch production. In an optimal scenario (don't be wrong... don't be wrong...) this would cover component-level electrically-accurate (because radiation) logic simulation that everything gets tested on first.

NASA doesn't mess around with simulators. I've read accounts from astronauts and ground controllers where they say their actual missions feel anticlimactic after all the insane things they had to do in the simulators. Gene Kranz managed to crash a simulated Apollo mission into a mountain.

The code on the computers has been upgraded, and even the language used to prpgram has changed over the years [1]. Which leads me to believe that the computer has been restarted/rebooted many times in all these years.

I think there may be other computers, right here on Earth, that may be able to at least compete given those criteria.

[1]: From the linked page:

> The CCS originally ran software written in the Fortran programming language, but this has been continually upgraded since its launch (software updates can be transmitted and installed remotely). The current software is written in a mixture of C and Fortran.

The following is fascinating.

> The age of the computer and its codebase has caused problems for NASA in recent years. In 2015 Larry Zottarelli, the last of the project's original programmers, retired, and it was difficult to find a replacement with such in-depth knowledge of what now seem like ancient hardware and design principles.

What an incredible project. Does anyone know of any good interviews or written content from the engineers?

There are tons of documentaries and interviews. [1]

[2] https://www.pbs.org/the-farthest/

What's more amazing is how NASA's Deep Space Network continues to make communication with Voyager possible.

https://www.nasa.gov/feature/jpl/nasa-contacts-voyager-2-usi...

I wonder what the ping/latency is...

~23.2B km / c (m/s) seconds, so about 43 hours or roughly the time to get through to an arbitrary customer service representative these days.

ping...

Hello. You've reached the Voyager I spacecraft. We can't answer your ping right now but if you'd like to leave a message, please, do so after the beep. We look forward to servicing your request as soon as possible.

(Current) One-Way Light Time = 21:35:13 [0]

So 43 hours 10 minutes 26 seconds minimum, excluding processing time.

That's probably another record... Although I'm pretty sure it can't process ICMPs, so "ping" in the more general sense.

[0] https://voyager.jpl.nasa.gov/mission/status/

That must be fun over SSH/Telnet. 43 hours between every key press

Joking, but thanks for the interesting info (and Frost1x also).

Come on, SSH and Telnet? That's ludicrous. It's a job for https://mosh.org/

At the very least, local echo must be enabled.

Neither ICMP nor IPv4 existed when the Voyager probes were launched in 1977 :) ICMP was created in 1981

Yeah, that's what I was implying ;D

I think an older probe also took the first digital pictures before bitmap images were a thing, they could digitise it at the probe end but had to colour in the pixels on a piece of paper at the other end if I recall correctly. Point is, NASA had to solve a lot of digital communication problems long before they had established terrestrial solutions or before computers were even capable of solving the whole problem on their own.

Then again, even if the timing was reversed, a lot of terrestrial communication protocols have no chance of working properly at the ranges required for space exploration - something I've been meaning to look into is the redundancy requirements over those long distances, since re-transmission is so costly in terms of latency that it probably makes sense to pack as much redundancy into the signal as possible, we already do this with terrestrial communication in the form of various codes, but there's a finer balance between increased bandwidth and the relatively low latency cost of re-transmission in the case of unrecoverable sequences... I'm guessing you want a far lower probability of loss for a 43 hour round trip.

And I used to get angry with 250ms ping playing WoW.

Which somehow is a dream on a few networks.

Reminds me of the early days of dial-up Internet... ;-D

The first modems were only 110 bps.

You mean bauds

It's both. 110, 300 and early 1200 were all one bit per symbol.