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/