NASA knows what knocked Voyager 1 offline, but it will take a while to fix

The next time you're having a frustrating debugging session, comfort yourself with the knowledge that you're not debugging a hardware issue on a computer built 50 years ago where it takes 45 hours to produce the output of every single command, and where failure means the loss of one of humanity's most important scientific relics.

So they&#x27;re saying that one memory chip in the FDS has failed, representing 3% of the FDS&#x27;s memory.<p>The FDS memory seems to be CMOS, which was apparently novel at the time of launch[0]. I suppose that means it&#x27;s static RAM. I have a notion that at least some CMOS SRAM came in 8-bit wide chips, storing 1-4 Kb. So that would imply total RAM of between 20Kb and 80Kb. I haven&#x27;t managed to track down many definite numbers or facts.<p>It&#x27;s programmed in FORTRAN77; it&#x27;s a very long time since I was adjacent to FORTRAN, but as I recall, all variables were global. I&#x27;m sure it&#x27;s tricky to write code that works even if there&#x27;s a hole in physical memory; but I guess the absence of heaps and caches must help a lot.<p>[0] <a href="https:&#x2F;&#x2F;www.allaboutcircuits.com&#x2F;news&#x2F;voyager-mission-anniversary-computers-command-data-attitude-control&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.allaboutcircuits.com&#x2F;news&#x2F;voyager-mission-annive...</a>

It would be fun to try to design a system that can work around all kinds of failures, such as being able re-purpose one subsystem to take over from another one.<p>For example, have all the digital electronics be reprogrammable gate arrays.

The film &quot;It&#x27;s quieter in the twilight&quot; might be of interest to folks on this thread. I saw it on Amazon Prime, but I think it is available on quite a few platforms, according to <a href="https:&#x2F;&#x2F;www.itsquieterfilm.com&#x2F;where-to-watch" rel="nofollow">https:&#x2F;&#x2F;www.itsquieterfilm.com&#x2F;where-to-watch</a>

I&#x27;m nervous asking, but a little curious what kind of equipment someone would need to give it different instructions. Does it use 1970s encryption? How big would your radio need to be?

&gt; The Flight Data Subsystem was an innovation in computing when it was developed five decades ago. It was the first computer on a spacecraft to use volatile memory. Most of NASA&#x27;s missions operate with redundancy, so each Voyager spacecraft launched with two FDS computers. But the backup FDS on Voyager 1 failed in 1982.<p>I wonder why they chose volatile memory: Were there performance demands that required it? How much did non-volatile memory cost back then?

Seems like the smartest thing to do would be to take everything that we have learned from all of this and launch more voyagers.

Not sure if old news or something new has come up.<p>See <a href="https:&#x2F;&#x2F;www.theregister.com&#x2F;2024&#x2F;03&#x2F;14&#x2F;voyager_1_not_dead&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.theregister.com&#x2F;2024&#x2F;03&#x2F;14&#x2F;voyager_1_not_dead&#x2F;</a> (discussion: <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=39704914">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=39704914</a>)<p><a href="https:&#x2F;&#x2F;www.cnn.com&#x2F;2024&#x2F;03&#x2F;14&#x2F;world&#x2F;voyager-1-communication-issue-poke-scn&#x2F;index.html" rel="nofollow">https:&#x2F;&#x2F;www.cnn.com&#x2F;2024&#x2F;03&#x2F;14&#x2F;world&#x2F;voyager-1-communication...</a> (<a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=39726235">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=39726235</a>)

Related NASA blog post<p><a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=39941090">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=39941090</a>

Seeing that picture of voyager, I wondered why we aren&#x27;t sending out more of these in every direction.

The fact that no one here mentions &#x27;aliens&#x27;, given the headline, disappoints me.