Voyager 1 runs on 69 KB of memory and an 8-track tape recorder

Voyager 1 & 2 is one of my favourite human science achievements, not even so much from technology standpoint, as it's relatively simple compared to what we have now (although that's one of the charms), but just the fact that it's so far away, it still more or less works long after the scheduled mission end time, we can communicate with it and despite all the modern technology progress, it would take decades to catch up. Absolutely amazing and inspiring!

The thruster fix is the part that gets me. They sent a command that would either revive thrusters dead since 2004 or cause a catastrophic explosion, then waited 46 hours for the round trip with zero ability to intervene. That's a production deployment with no rollback, no monitoring dashboard, and a 23-hour latency on your logs. They nailed it.

There is a terrific documentary, 'Its quieter in the twilight', about the aging and dwindling team that still runs both Voyager missions https://www.youtube.com/watch?v=F6L9Du_IFmI

Very depressing to see this next to the "LinkedIn uses 2.4GB of RAM" post.

Here's a photo of the tape recorder:

https://science.nasa.gov/image-detail/voyager-digital-record...

Reminded me of the anecdote mentioned in the classic "Real Programmer Don't Use Pascal"

> Some of the most awesome Real Programmers of all work at the Jet Propulsion Laboratory in California. Many of them know the entire operating system of the Pioneer and Voyager spacecraft by heart. With a combination of large ground-based FORTRAN programs and small spacecraft-based assembly language programs, they are able to do incredible feats of navigation and improvisation -- hitting ten-kilometer wide windows at Saturn after six years in space, repairing or bypassing damaged sensor platforms, radios, and batteries. Allegedly, one Real Programmer managed to tuck a pattern-matching program into a few hundred bytes of unused memory in a Voyager spacecraft that searched for, located, and photographed a new moon of Jupiter.

> The current plan for the Galileo spacecraft is to use a gravity assist trajectory past Mars on the way to Jupiter. This trajectory passes within 80 +/-3 kilometers of the surface of Mars. Nobody is going to trust a PASCAL program (or a PASCAL programmer) for navigation to these tolerances.

The article is satirical so I am not sure how true is this, but over its history, the maintainers of these probes have done truly remarkable stuff like this.

https://homepages.inf.ed.ac.uk/rni/papers/realprg.html

Voyager is an awesome mission. But the AI fingerprint in the piece is a turn off.

One of my favorite stories about the Voyager mission was how they wanted to grab photos of the outer planets but the click of the tape drive was enough to ruin the long exposures. I made a YouTube short about it a while back:

https://youtube.com/shorts/fssIy-wQisA?si=_HM1fgZKGFfaxWhc

Good they launched Voyager 1 before invention of Docker, Electron and NPM projects with thousands of padLefts.

Wow! Reading this after watching PHM I almost cried...again.

Now, this is what impressed me the most: ""... and wrote software flexible enough to be updated from Earth decades after launch.."

OTA patches where invented in the 70's :)

Nice. I’ve done some of my best learning by trying to do things with very artificially low resource constraints. The struggle I have at times is to properly calibrate my brain to the right resource scope. Ie. “No, stop optimizing these enums as integers instead of strings… this isn’t the game boy emulator this is a web browser. It’s fine.”

There’s a lot of LLM text in that article. It’s very offputting.

I know it makes no sense about what I'm going to say but: whenever I lose a 'simple 5G phone call' connection I remind myself that the Voyager 1 runs on 69kb of memory and there's a robot on Mars.

What really gets me is that the time between windows 95 and now is more than between voyager launching and Windows 95. Same for the moon landings for that matter.

I feel like that's also what's running the backend of Spirit Airlines, but somehow it feels more impressive in the context of Voyager 1.

It's very distracting to have every sentence in this article be its own paragraph.

Archive link: https://web.archive.org/web/20260329164132/https://techfixat...

I’ve been looking at emulation for the first time in a long time, and it also blows my mind that entire big detailed games that we played for many hours take 100-400kb total (NES) or 2-4mb (Genesis).

Amaze. Amaze. Thank you for sharing.

Wish javascript devs would read this. If the web is slow, its because of them

I watched a documentary about Voyager once. It was fascinating seeing all these men and women huddled around a tiny little screen and a telex printer to see all their theories about Saturn become real.

It was the Neil Armstrong moment for astronomy.

Very cool, first time reading about the specifics of voyager 1, this is super impressive!

> For the first time in the history of the universe, as far as we know, an object built by a living species had left the protective bubble of its home star system...

Seriously?

I knew about the memory, but an 8-track tape ? That is a surprise. But when you think of it, what else could you use for this in 1977.

What amazes me is the tape lasted almost 30 years. I knew tapes back then could last a while, 30 years being bombarded with cosmic rays ? inconceivable :)

This is one mighty tape recorder, hats off:

https://space.stackexchange.com/questions/2053/how-was-magne...

I'm just going to repost stuff from my blog about the Voyager space probes. I've posted this here before -

The two Voyager spacecraft are the greatest love letters humanity has ever sent into the void.

Voyager 2 actually launched first, on August 20, 1977, followed by Voyager 1 on September 5, 1977. Because Voyager 1 was on a faster, shorter trajectory (it used a rare alignment to slingshot past both Jupiter and Saturn quicker), it overtook its twin and became the farther, faster probe. As of 2025, Voyager 1 is the most distant human-made object ever, more than 24 billion kilometers away, still whispering data home at 160 bits per second.

Each spacecraft carries an identical 12-inch gold-plated copper phonograph record.

The contents:

- Greetings in 55 human languages.

- A message from UN Secretary-General at the time and one from U.S. President Jimmy Carter.

- 115 analog images encoded in the record’s grooves: how to build the stylus and play the record, the solar system’s location using 14 pulsars as galactic GPS, diagrams of human DNA, photos of a supermarket, a sunset, a fetus, people eating, licking ice cream, and dancing

The record is encased in an aluminum jacket with instructions etched on the cover: a map of the pulsars, the hydrogen atom diagram so aliens can decode the time units, and a tiny sample of uranium-238 so they can carbon-date how old the record is when they find it.

Sagan wanted the record to be a message in a bottle for a billion years. The spacecraft themselves are expected to outlive Earth. In a billion years, when the Sun swells into a red giant and maybe swallows Earth, the Voyagers will still be cruising the Milky Way, silent gold disks carrying blind, naked humans waving hello to a universe that may never wave back.

And it was Sagan who, in 1989, when Voyager 1 was already beyond Neptune and its cameras were scheduled to be turned off forever to save power, begged NASA for one last maneuver. On Valentine’s Day 1990, the spacecraft turned around, took 60 final images, and captured Earth as a single pale blue pixel floating in a scattered beam of sunlight — the photograph that gives the book its name and its soul.

It was the photograph that inspired this famous quote -

"Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there-on a mote of dust suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot.

Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.

It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known. "

That picture almost didn’t happen. NASA said it was pointless, the cameras were old, the images would be useless. Sagan argued it would be the first time any human ever saw our world from outside the solar system. He won. The cameras were powered up one last time, the portrait was taken, and then they were shut down forever.

Full piece - https://www.rxjourney.net/30-things-i-know

but can it play Doom?

Decommission. It's not AI ready.

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so unbelievable that makes you wonder if its all fake.

And what did we get from this space innovation?

Not the cheap prosumer high density backup tape drives that we should be able to buy in the stores now.