NASA has reestablished full communications with Voyager 2
jpl.nasa.gov
jpl.nasa.gov
I was born in the early 70's and the Voyager's have been travelling most of my life. In some ways they're like a touch-stone, something I always click on when I see an article.
One day, like me, they'll finally die, but until then may they travel onwards and outwards.
A tip of the hat to folks at NASA and JPL that built this marvel, with 70's tech, that still continues to amaze and delight us.
The worst that could have happened is that the spacecraft would have kept the dish in the wrong position until October, at which point it would have re established contact. This isn’t even the last time the Voyager program has had similar outages, IIRC they had to shut down the dish for maintenance for several months and when they re established contact the spacecraft was fine. They should review their MOPS procedures so this doesn’t happen again (it’s generally standard practice to run commands against a simulated version of the spacecraft in a similar operating condition or a replica to make sure it won’t do something destructive) but from the first time I saw the headline for this my first thought was “lmao” and I was never really worried this would cause lasting problems for the spacecraft.
Is there by any chance literature you'd recommend about this kind of tech? Maybe more on the lighter side?
Here’s a good article specific to Voyager https://www.allaboutcircuits.com/news/voyager-mission-annive...
I can’t find it but there was a slide deck online for Curiosity with an explanation of all the stuff I was talking about above
in case anyone got confused like me - receiver dish _on Earth_ was shut down
Some of the risks involved are - we don't have a good model of the flying hardware. The telemetry is extremely limited and engineers who made / understand it are scarce. Current situation of messing up commands is one of the consequences of that. There is a number of faults that are isolated and recovered via software workarounds, any kind of reset could default you in a non functional configuration. This is aging hardware that is slowly deteriorating, severed comms stop your ability to react to the events.
The overall risk of permanent contact loss was probably low, but due to all the unknowns the error bars are quite high.
I thought mostly of "wow". They had a plan for a case when this "shout" didn't work. So they had at least two plans what could be done and the first one worked all right.
Half a century and 20 billion of kilometres from Earth and it still works.
This is part of a larger series of publications that may be of interest. https://descanso.jpl.nasa.gov/DPSummary/summary.html
EEVblog 1547 (Part 1) - Contacting the Voyager 2 Space Probe: https://www.youtube.com/watch?v=586Zn1ct-QA
EEVblog 1547 (Part 2) - PINGing the Voyager 2 Space Probe!: https://www.youtube.com/watch?v=vUvzgZt1Vug
EEVblog 1547 (Part 3) - Tour of the NASA Canberra Deep Space Communications Complex: https://www.youtube.com/watch?v=vfZz4EnhJBE
https://www.amazon.com/NASA-Voyager-Owners-Workshop-Manual/d...
It has a chapter titled "Voyager - The Flying Computer Center". [2] It gives a high-level overview of the computers and software. Three different processors, each dual redundant. 18 and 16 bit machines. Comparable to early 1970s minicomputers.
There's a good talk about the computers on the Voyagers available online here. [3]
As far as I know, beyond what's available between those two sources, very little otherwise is available publicly on the computer hardware itself - no detailed architecture descriptions, instruction sets, electronics details, etc. And no software listings. Though if I had to guess the 18-bit machines are a lot like - but not the same as - the OBP/AOP/NSSC series [4].
A bit of Voyager trivia: the computers were reprogrammed in-flight to give new abilities the Voyagers didn't have at launch, such as new image compression algorithms to allow more images to be returned than originally anticipated.
[1] https://history.nasa.gov/computers/contents.html
[2] https://history.nasa.gov/computers/Ch6-2.html
Though I have to admit disagreeing with that rule of thumb on almost every point.
There's also a brief scene in which a Klingon ship destroys a different Voyager probe in "Star Trek V: The Final Frontier".
The vehicle records flight and sensor data to tape, and then periodically broadcasts that back to earth. As of 2022 the tape drive appears to be still working [1].
For software, I fear complexity would make it much harder to build something that works for 50+ years, the probability of some nasty long term overflow bug or slow memory leak would make that difficult.
Yes, although that is very rarely a design goal.
>For software, I fear complexity would make it much harder to build something that works for 50+ years, the probability of some nasty long term overflow bug or slow memory leak would make that difficult.
Not that hard to handle. You just need to setup an appropriate architecture. In Aeronautic software systems you often have forced resets, if the software is not reaching certain points of exrcution. You also do not have memory leaks, since you do not have dynamic memory.
https://www.abc.net.au/news/2023-08-05/nasa-restores-contact...
Keeping an eye on CSIRO's Tidbinbilla website might yield some info as they get around to writing things up. It's the "horse's mouth" so to speak, as all Voyager communications goes via Tidbinbilla.
https://www.csiro.au/en/news/All/Articles/2023/August/Voyage...
It seems that they just used a different, more powerful transmitter than usual.
I know that's what they say, but does anyone have any more details about that, too?
It's hard for me to reconcile the idea that the probe can automatically re-orient itself with the idea that it somehow got accidentally pointed in the wrong direction. You'd think they'd end every set of commands with instructions to check orientation and fix it if it's wrong.
there are recalibrations every few months to make sure the antenna is pointed at the earth.
video explanation of how it works- pretty ingenious:
Now I just made up those numbers. but the cool thing about nasa is how open they are. both when things go wrong "whoops we misaligned voyeger 2" and with specs, it probably won't take me long at all to find actual numbers.
update: Found this page which is pretty cool.
The centre of the signal was something like 69 million KM off to the side of earth. 20% of of earths orbital diameter.
I suppose the difference is the effective receive angle, and by turning up the power they could get it to respond.
(yeah i know i know wrong voyager just let me have this moment)
But just because you know the protocol dues not mean you have enough information to send a valid command. The commands are wrapped in a common protocol, but the commands themselves are typically mission-specific and definitely not made public.
Here’s an example of someone unaffiliated with the mission decoding JWST telemetry. While they were able to identify the packets defined per CCSDS protocols, they do not know the actual content of the packets, which are mission specific.
https://destevez.net/2021/12/decoding-james-webb-space-teles...
And as someone else mentioned, the biggest hurdle with getting a command to voyager is access to a 70 m dish. Not many of those floating around…
> And as someone else mentioned, the biggest hurdle with getting a command to voyager is access to a 70 m dish. Not many of those floating around…
And that's what I meant by if possible. Haha.
We definitely have the capacity to build spacecraft to the quality standards of Voyager. Samsung would probably be willing to support your 2023 era Galaxy cell phone, if you're willing to spend $800m on it.
I am lucky if my cell phone lasts more than a year. That's definitely you, not the phone. Most people's phones last longer. Partially evidenced by folks complaining about updates stopping after a few years.
I have a feeling that even if today's hardware manages to last 50 years, all knowledge of how to talk to it will be long lost. I am sure some of the code/firmware will be proprietary and then contractor will go out of business and that is that. Most of today's hardware isn't expected to last that long - and it wouldn't matter if much of it did. No one wants 50-year-old medical equipment unless it hasn't improved in 50 years. A 25-year-old computer isn't worth much to the average consumer. And some stuff will just be outdated: Do you really want to use one of the digital typewriters that combine a small-screen simple word processor with a typewriter?
Things that we build for longer-term science generally is built to a different standard than the stuff we use at home and has different constraints and different sorts of moving parts. Especially when considering extreme environments. And most of these are made by governments, universities, and other institutions that tend to have a long lifespan when compared to corporations. And when they aren't, we can make sure to make laws so others can use science research things even if the company closes.
Additionally: I think everyone expected Voyager to die long ago. It is akin to a fridge that happens to still be running 50 years later. A lucky accident.
This speaks more to the quality of engineering than lucky accidents.
NASA sets high bars because many of these projects have a single chance of working. They make decisions that maximize the chances that the equipment will function within mission parameters, and the result is often something that far exceeds the original mission. See: Mars helicopter.
In the consumer space, an old fridge continuing to operate isn’t chance either. This truly is a case of “they don’t make them like they used to”.
Edit: I’m a bit surprised this is controversial. Curious why people feel this is wrong.
Also something about Cuba. I think my point is that we're a bit too cavalier with used electronics these days. The embodied energy and materials are huge, and we just... throw them out, in many cases. I'd like us to get used to repurposing these resources before scarcity forces us to. Really squeezing every bit of use out of them that we can. Bonus: because it's not the Hot New Thing Someone Is Trying To Sell You, you'll likely be less subject to the Hot New Trend Of Actually Being The Product.
And, for what it's worth: an original Apple I just sold for almost $450k at auction. Someone wanted that.
My comment is unfortunately an example where I let my late night shit-posting bleed over into HN, which is always regretted in the morning. Apologies ;)
New Horizons is similar, now at 18 years since launch and still counting.
They're not quite 50 yet, but there's no reason to think either couldn't make it that long.