this post was submitted on 06 May 2024
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Science Memes

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[–] [email protected] 9 points 11 months ago (2 children)

I still cannot believe NASA managed to re-establish a connection with Voyager 1.

That scene from The Martian where JPL had a hardware copy of Pathfinder on Earth? That’s not apocryphal. NASA keeps a lot of engineering models around for a variety of purposes including this sort of hardware troubleshooting.

It’s a practice they started after Voyager. They shot that patch off into space based off of old documentation, blueprints, and internal memos.

[–] [email protected] 5 points 11 months ago (1 children)

Imagine scrolling back in the Slack chat 50 years to find that one thing someone said about how the chip bypass worked.

[–] [email protected] 3 points 11 months ago (1 children)

Imagine any internet company lasting 50 years.

[–] [email protected] 2 points 11 months ago (1 children)

This is why slack is bullshit. And discord. We should all go back to email. It can be stored and archived and organized and get off my lawn.

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[–] [email protected] 1 points 11 months ago

To add to the metal, the blueprints include the blueprints for the processor.

https://hackaday.com/2024/05/06/the-computers-of-voyager/

They don't use a microprocessor like anything today would, but a pile of chips that provide things like logic gates and counters. A grown up version of https://gigatron.io/

That means "written in assembly" means "written in a bespoke assembly dialect that we maybe didn't document very well, or the hardware it ran on, which was also bespoke".

[–] [email protected] 5 points 11 months ago (3 children)

To me, the physics of the situation makes this all the more impressive.

Voyager has a 23 watt radio. That's about 10x as much power as a cell phone's radio, but it's still small. Voyager is so far away it takes 22.5 hours for the signal to get to earth traveling at light speed. This is a radio beam, not a laser, but it's extraordinarily tight beam for a radio, with the focus only 0.5 degrees wide, but that means it's still 1000x wider than the earth when it arrives. It's being received by some of the biggest antennas ever made, but they're still only 70m wide, so each one only receives a tiny fraction of the power the power transmitted. So, they're decoding a signal that's 10^-18 watts.

So, not only are you debugging a system created half a century ago without being able to see or touch it, you're doing it with a 2-day delay to see what your changes do, and using the most absurdly powerful radios just to send signals.

The computer side of things is also even more impressive than this makes it sound. A memory chip failed. On Earth, you'd probably try to figure that out by physically looking at the hardware, and then probing it with a multimeter or an oscilloscope or something. They couldn't do that. They had to debug it by watching the program as it ran and as it tried to use this faulty memory chip and failed in interesting ways. They could interact with it, but only on a 2 day delay. They also had to know that any wrong move and the little control they had over it could fail and it would be fully dead.

So, a malfunctioning computer that you can only interact with at 40 bits per second, that takes 2 full days between every send and receive, that has flaky hardware and was designed more than 50 years ago.

[–] [email protected] 3 points 11 months ago (1 children)

And you explained all of that WITHOUT THE OBNOXIOUS GODDAMNS and FUCKIN SCIENCE AMIRITEs

[–] [email protected] 1 points 11 months ago

Oh screw that, that's an emotional post from somebody sharing their reaction, and I'm fucking STOKED to hear about it, can't believe I missed the news!

[–] [email protected] 1 points 11 months ago (1 children)

Is there a Voyager 1, uh...emulator or something? Like something NASA would use to test the new programming on before hitting send?

[–] [email protected] 1 points 11 months ago

Today you would have a physical duplicate of something in orbit to test code changes on before you push code to something in orbit.

[–] [email protected] 1 points 11 months ago

Finally I can put some take into this. I've worked in memory testing for years and I'll tell you that it's actually pretty expected for a memory cell to fail after some time. So much so that what we typically do is build in redundancy into the memory cells. We add more memory cells than we might activate at any given time. When shit goes awry, we can reprogram the memory controller to remap the used memory cells so that the bad cells are mapped out and unused ones are mapped in. We don't probe memory cells typically unless we're doing some type of in depth failure analysis. usually we just run a series of algorithms that test each cell and identify which ones aren't responding correctly, then map those out.

None of this is to diminish the engineering challenges that they faced, just to help give an appreciation for the technical mechanisms we've improved over the last few decades

[–] [email protected] 2 points 11 months ago (1 children)

Keep in mind too these guys are writing and reading in like assembly or some precursor to it.

I can only imagine the number of checks and rechecks they probably go through before they press the "send" button. Especially now.

This is nothing like my loosey goosey programming where I just hit compile or download and just wait to see if my change works the way I expect...

[–] [email protected] 1 points 11 months ago

they almost certainly have a hardware spare, or at the very least, an accurately simulated version of it, because again, this is 50 year old hardware. So it's pretty easy to just simulate it.

But yeah they are almost certainly pulling some really fucked QA on this shit.

[–] [email protected] 2 points 11 months ago

I think the term "metal" is overused, but this is probably the most metal thing a programmer could possibly do besides join a metal band.

[–] [email protected] 2 points 11 months ago (1 children)

Why do Tumblr users approach every topic like a manic street preacher?

[–] [email protected] 1 points 11 months ago (1 children)

There's a significant overlap between theatre kids and Tumblr users.

[–] [email protected] 1 points 11 months ago

That ven diagram is maybe 3 degrees away from a circle.

[–] [email protected] 2 points 11 months ago

When I hear what they did, I was blown away. A 50 year old computer (that was probably designed a decade before launching) and the geniuses that built that put in the facility to completely reprogram it a light-day away.

[–] [email protected] 2 points 11 months ago (4 children)

Still faster than the average Windows update.

[–] [email protected] 0 points 11 months ago (3 children)
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[–] [email protected] 2 points 11 months ago

Interviewer: Tell me an interesting debugging story

Interviewee: ...

[–] [email protected] 1 points 11 months ago (3 children)

People always underestimate the high level NASA works at. Everyone bitches and moans, especially Musk simps, about how long SLS took to make and its expense, but it worked right the first time. In the case of the Voyager spacecraft, they are working with tech so old, all the original engineers are retired or dead. NASA rocks.

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[–] [email protected] 1 points 11 months ago (1 children)

Meanwhile here on Earth, we need to login using two accounts to access Helldivers 2. And even got pulled from many countries. What a time to be alive.

[–] [email protected] 1 points 11 months ago

Sony has agreed to remove psn requirements for pc users now

[–] [email protected] 1 points 11 months ago (1 children)

I just have to imagine how interesting of a challenege that is. Kinda like when old games only had 300kb to store all their data on so you had to program cool tricks to get it all to work.

[–] [email protected] 1 points 11 months ago (1 children)

No yeah, it's like that plus the thing is a light day away, and on top of that malfunctioning on a hardware level. Incredible

[–] [email protected] 1 points 11 months ago

It’s like you already have a 300kb game on a cartridge, but it doesn’t work for some unknown reason. Also you don’t actually have the cartridge, some randy in Greenland does. And they only answer emails once every 2 days or so.

[–] [email protected] 1 points 11 months ago

It reminds me that there are still very intelligent and talented people within our ranks. A nice breath of fresh air.

[–] [email protected] 1 points 11 months ago

I wont even upgrade the BIOS on my motherboard because im afraid of bricking it.

[–] [email protected] 1 points 11 months ago

Great documentary on the Voyager team: It's quieter in the twilight

[–] [email protected] 1 points 11 months ago

Man I can’t even get my stupid Azure deployment to work and that’s only in Germany.

[–] [email protected] 1 points 11 months ago* (last edited 11 months ago) (1 children)

It's hard to explain how significant the Voyager 1 probe is in terms of human history. Scientists knew as they were building it that they were making something that would have a significant impact on humanity. It's the first man made object to leave the heliosphere and properly enter the interstellar medium, and this was always just a secondary goal of the probe. It was primarily intended to explore the gas giants, especially the Jovian lunar system. It did its job perfectly and gave us so many scientific discoveries just within our solar system.

And I think there's something sobering about the image of it going on a long, endless road trip into the galactic ether with no destination. It's a pretty amazing way to retire. The fact that even today we get scientific data from Voyager, that so far away we can still communicate with it and control it, is an unbelievable achievement of human ingenuity and scientific progress. If you've never seen the image the Pale Blue Dot you should see it. That linked picture is a revised version of the image made by Nasa and released in 2020. It's part of a group of the last pictures ever taken by Voyager 1 on February 14th 1990, a picture of Earth from 6 billion kilometers away. It's one of my favorite pictures, and it kinda blows my mind every time I see it.

[–] [email protected] 1 points 11 months ago (1 children)

The pale blue dot photo always makes me tear up. We're so small and insignificant in such a grand universe and I'm crushed that I can't explore it.

[–] [email protected] 1 points 11 months ago

There will always be a "step further we'd love to see but won't". Let's be glad we're in that step which included this photo and the inherent magnificence in it.

It totally beats being one of the earlier humans who just wondered what the lights in the sky might be. Probably gods or something.

[–] [email protected] 0 points 11 months ago (2 children)

Let's hope the over-the-air update didn't get Man-In-The-Middled...

[–] [email protected] 1 points 11 months ago

Suspect #1:

[–] [email protected] 1 points 11 months ago

Voyager is a boomer and could more easily be phished

[–] [email protected] 0 points 11 months ago (1 children)

My understanding is that they sent V'Ger a command to do "something," and then the gibberish it was sending changed, and that was the "here's everything" signal.

And yeah, I'm calling it V'Ger from now on.

[–] [email protected] 0 points 11 months ago (1 children)

And yeah, I'm calling it V'Ger from now on

Have my upvote.

Why haven't we been doing this already? I'm with you, let's make this happen!

[–] [email protected] 1 points 1 month ago

Stop trying to make V'ger happen! Its not going to happen!

[–] [email protected] 0 points 11 months ago* (last edited 11 months ago) (5 children)

I wonder how it is secured, or could anyone with a big enough transmitter reprogram it at will...

[–] [email protected] 2 points 1 month ago

Its partially because there is only one set of antennas large enough to communicate with it, and that's only sometimes. Its called the Deep space network and it is very secure because it's used for many things, not just communicating with the Voyager probes.

Second, you'd have to have very very intimate knowledge of the hardware, and programming language to even begin to hack it. And the people who do have that knowledge are very very passionate about their probes.

So I guess technically the answer is yes. But practically, no.

[–] [email protected] 1 points 11 months ago (3 children)

I think the security is adequately managed by the need for a massive transmitter as well as the question "what is there to gain via a hostile takeover and re-programming the probe?"

I bet there's actual security of some kind going on, but those two points seem like a massive hurdle to clear just to mess with a deep space probe.

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