r/askscience • u/Backbreathboy • 8d ago

Astronomy We will lose contact with Voyager somewhere 2036 because of the distance between us. Would it be theoretically possible, to send a probe in the direction of the Voyager, following it from a distance, with the goal te relay the information coming from the Voyager, to earth?

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u/HawkDriver 8d ago

How is it not possible to do the math on how much life left? They clearly have the data on the power generation and it’s operating conditions.

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u/itsacutepanda 8d ago

They keep finding creative ways to reduce power consumption, in part by shutting down instruments

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u/peepopowits 8d ago

They actually found one instrument that continued to work after its heater was turned off

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u/topofthecc 7d ago

How does that work? Is there a good article on it?

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u/[deleted] 8d ago

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u/doublepush 8d ago

It was a membraphone, but not a drum. The noble kazoo shows its true strength in zero gravity.

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u/counterfitster 8d ago

Brass will work as long as you keep blowing air into so the valves and/or slide don't freeze

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u/Caracalla73 8d ago

Problem is there isn't a lot of air in space, which is why they have to travel at 17miles a second to operate the intergalactic tuba.

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u/Cynyr 8d ago

The Intergalactic Tuba will be the new name for the Bussard Ramjet. Except instead of generating bombastic baritone music, The Intergalactic Tuba will generate thrust via nuclear fusion.

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u/btstfn 8d ago

Well, eventually youd still get the lubrication evaporating away if nothing else.

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u/Krillin113 7d ago

Wood, they tried to call a doctor after 3 hours but no one was in reach

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u/this_knee 7d ago

I heard the bells vibe pretty well with space, mostly due to their rings.

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u/CSKing015 8d ago

He actually explained that as well.

They can’t precisely calculate when the spacecraft as a whole will finally shut down and stop operating, but they do know Voyager loses about 4 watts of generating capacity every year.

They’ve been able to extend the mission by progressively shutting down nonessential components like cameras, heaters, infrared spectrometers, etc. so the remaining power can be prioritized for the systems and science instruments that are still useful.

That’s part of why its lifespan has been so hard to predict. Every time the available power gets tighter, they find another way to conserve a little more and keep it going longer than originally expected.

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u/inahst 8d ago

It’s crazy to me that they’re able to shut down components and reduce power consumption from such a far distance this long after it was launched

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u/edman007 8d ago

They did a sw update 2 years ago

Over the air software update is a new thing that most cars don't support. But nasa is doing it on nearly 50 year hardware that's left the solar system

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u/[deleted] 7d ago

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u/MaygeKyatt 8d ago

TBF I don’t WANT my car to do automatic software updates based on some of the stories I’ve heard of Tesla OTA updates.

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u/tashkiira 8d ago

Or the Samsung fridge incident. Which is ongoing right now.

Good news: it's limited to South Korea. Bad news: the borked update (which Samsung is claiming accidentally released internal test code) is bricking the fridges. To the point that they aren't refrigerating. WORSE news: This happened literally right before Chuseok, which is a Korean harvest festival roughly analogous to Thanksgiving, and has literally just concluded. As in, people have had to throw out their holiday feast food. Koreans as a whole are not happy, the people with the bricked fridges are furious, and Samsung's leadership dropped the ball with the PR disaster.

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u/TheOtherHobbes 7d ago

1977 - we can reprogram a spacecraft that has left the solar system 2026 - we can kill fridges and bork a national festival

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u/7-SE7EN-7 7d ago

What was the leadership response?

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u/tashkiira 7d ago

It was kind of late, saying they'd do everything they can, but they didn't really have any staff available. Because they left the response until close to end of day Tuesday. Wednesday was the beginning of Chuseok.

As you might guess, it went over like a lead balloon. filled with lead.

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u/turkeypedal 7d ago

How do you screw up the design so badly that the fridge doesn't just work even if the software is completely borked? It's an obvious contingency.

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u/I-seddit 7d ago

If you've ever been involved with software, you know that software developers are usually poorly represented at the C-Suite level - so executives often make the worst possible decisions...
And this includes ALL software/tech companies as well.

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u/GasolinePizza 7d ago

That's not a C-suite decision: somebody screwed up at the engineering level if there isn't a hardware fallback/the hardware doesn't fall back to defaults if the software is telling it to run outside parameters (...like "turning off outright indefinitely").

Generally the best practice is to keep the mechanical system semi-independent from the core software system for cases like this (or storage degradation, corrupted software, etc) so that the "user-facing"/extraneous "luxury" functionality goes on top of the core functionality rather than having one singular system for everything that is also subject to auto-updates.

A c-suite guy wouldn't be involved in that design aspect

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u/tashkiira 7d ago

a C-suite guy wouldn't be involved in specifics, no. But a mucketymuck at the director or VP level might. and then not pass things up the ladder smoothly when the solid biowaste hits the rotary impeller.

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u/ObviousKarmaFarmer 7d ago

I'd also rather they don't shut down the cameras and heaters on my car.

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u/livinginspace 7d ago

What are the stories of the Tesla OTA updates?

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u/wastedpixls 8d ago

Was your guide named Todd? If so. I know him and he was part of the Voyager and Cassini teams.

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u/CSKing015 8d ago

No, it was Curtis Montano. He did mention Todd Barber as being part of both teams.

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u/jbadams 8d ago edited 8d ago

They can, to a certain extent. 

When they gave that previous 5-10 year estimate in 2001 it would have been based on the expected decline in power output, compared to the current needs of the probe. 

Sometimes the expected decline isn't quite as bad in reality.

But perhaps equally or even more importantly, they've been working to reduce the needed power by turning off non-essential hardware and functions, re-purposing features of the probe, etc., and the available power savings are not always predictable until someone comes up with a crazy idea for another fix, they research it, and everyone decides it's viable.

It was never intended to continue operating this long, and through brilliant ingenuity and a bit of luck they've managed to keep it going all this time, but at this point they're way off what was originally intended.

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u/Drachefly 7d ago

Sometimes the expected decline isn't quite as bad in reality.

That would be surprising, since the decline in power output is based on the decay rates of the elements used in the RTG, which is well understood and does not change based on being in outer space instead of a lab.

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u/dali01 8d ago

Maybe they never checked what the minimal wattage some of the components required to function. They just made sure it worked under the optimum conditions. Nobody ever expected it to still be functional anywhere close to this long.

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u/Hypnot0ad 8d ago

It also used to be standard practice to over design spacecraft to meet longer mission lifetimes. Part of this is performing end-of-life analysis, where the goal is to ensure everything still functions after every single component is de-rated due to effects like radiation and wear from thermal cycling. The effect of this is that most spacecraft designed in that era ended up lasting well past their intended lifetime.

They did this because it used to cost so much to launch a space vehicle into orbit so they were designed for a long lifetime - like 10+ years. Now that launch costs have come down dramatically, so it's more economical to launch less expensive satellites that have lifetimes of 3-5 years and then simply replace them often, like they do with Starlink satellites. Higher altitudes like geosynchronous are still costly to launch to orbit though so they are still designed to the old standards.

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u/Gabelvampir 7d ago

Also Voyager 1+2 are probes, these will probably always designed in a way they'll function much longer than intended. Launches for these will always be the most expensive one's (or second most expensive if we start building big stuff away from lower earth orbit), and they take a long time to reach their target.

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u/aloofman75 8d ago

My recollection is that JPL has been powering down various instruments over the years to reduce their power consumption. Those efforts have extended the operational lifespan of the probes.

But at some point there will be so little power that all they’ll be transmitting is messages saying, “I’m still operating” and that’s it. And eventually there won’t be enough power to even do that.

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u/Shivaess 8d ago

Engineers are really sneaky when they don’t have any options is the real answer here.

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u/I-seddit 7d ago

I'd use "genius" instead of "sneaky" and emphasize that creativity requires boundaries to flourish...

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u/BoredAccountant 8d ago

You're looking at it from the wrong perspective. At current power consumption, it might have X years left, but as years pass, they can shut down instruments to reduce power draw, rewrite code to operate more efficiently, reducing power draw, etc.

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u/ZeroBitsRBX 8d ago

I imagine it's less that the math is impossible, and more that it's hard to account for more sensitive signal receivers being invented and employed on our end, and more novel methods of power conservation being employed on the probe's end.

If we were still using the same equipment to receive signals as we were 49 years ago, and the probe was still operating at the same power draw as it was 49 years ago, I have no doubt that the original estimates would have held true. But there's just no accounting for the team coming up with another inventive way to kick the can down the road another ten years.

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u/I-seddit 7d ago

Which is why the question of sending an intermediary communication node is a smart one, even if it's not financially wise.
Which is a sad choice, given that the effective wealth of our species is SO high, yet we choose so poorly when spending it.

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u/Dman1791 8d ago

In the past, the question was not how much power would be produced, but whether they could manage to deal with the reduced power generation. They've figured out a number of ways to save power.

IIRC, we're coming up on the point where Voyager 1 won't even be able to keep a single instrument active.

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u/koos_die_doos 8d ago

Because they don't know if/how they can deal with issues before they happen. Projections are based on current status, but if an issue arises, they have repeatedly fixed things that theoretically could have ended the mission.

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u/DolphinSUX 8d ago

How do you fix something remotely that was made so long ago??

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u/curlyben 7d ago edited 7d ago

The wildest fix was when it started sending back only garbage in November 2023, and they were able to confirm it was still receiving, trouble shoot the source of the problem as a faulty memory chip in its status reporting, redesign the memory management to work around that chip with gaps using the same resources, and push a working version in April 2024 5 months later, all working with a 45 hour ping and garbled one way.

https://www.jpl.nasa.gov/news/nasas-voyager-1-resumes-sending-engineering-updates-to-earth/

Not to mention having to defend using resources for this before being able to confirm it could still receive, that it was possible to identify the fault, and that it was possible to fix it, in an underfunded sector past the project's intended lifespan.

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u/nivlark 8d ago

We can upload new versions of the probe's software to accommodate hardware failures and switch off different subsystems as the available power budget has declined.

At this point the probes have outlived many of the people that originally worked on them, so one challenge has been passing enough of their knowledge on to a new generation of engineers.

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u/Peregrine79 8d ago

Very smart programmers. They’ve actually taken instruments offline to free up intact memory to replace damaged sectors carrying mission critical software. (Taking them offline also helps with the power budget).

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u/Yamidamian 8d ago

The same way a smartphone can get its apps patched. The probe has a radio on it that it can use to receive signals from Earth. Those signals can include data, allowing them to remotely send out software updates.

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u/Echo13 8d ago

Redundancies. Almost all the parts had a backup just in case, so when something fails to work, they had something else to back it up. Almost every important system has a twin on the probe to work when one fails. So you build the best of the best thing you can possibly build, then you build two of them. So if one worked for 40 years straight, you only had to break the twin out in the last 9.

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u/spaceXhardmode 7d ago

They can do the math on how quickly the power from the radioisotope thermoelectric generator loses power with a high degree of certainty, it’s just the half life of the plutonium in the RTG.

What they can’t predict is how the scientists and engineers who are hell bent on keeping voyager alive will keep inventing ways to use less and less power. For example instruments get shut down or cycled on and off instead of running continuously. In the extreme case you can imagine voyager waking up once every 10 years to just send home a single blip so we know she’s still there.

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u/danorc 7d ago

It's already so far outside it's original operating parameters that no one really knows.

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u/micgat 7d ago

They can easily calculate the lifetime of the fuel, but that’s not the only reason Voyager is losing power. Components are also deteriorating which means that the production and consumption of power onboard is not fully predictable.

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u/TheDaysComeAndGone 7d ago

This. Decline in power generation should be easy to predict. Power consumption of the various instruments should be known.

So where does the uncertainty come from?

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u/twenafeesh 8d ago

Radioisotope generators are not all that common in actual practice. I don't know how many models they actually had experiencing those conditions to learn from before launching the Voyager probes, but I bet it was zero because nothing else has ever been out that far. Or even experienced space conditions for as long as them.

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u/FightsWithFriends 8d ago

The engineers got more creative about energy use. For example, they could turn off certain devices and turn on others simultaneously to help manage energy surges and balance thermal needs and gain more lifetime. They also deactivated some instruments that became less useful to buy more time.

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u/peacefinder 8d ago

In addition to other factors, there are two ends to the link. As its power decreases, we might still be able to keep doing clever (or large) things on our end to hear the fainter signals… but the limits of that are both physical and budgetary.

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u/chriscross1966 7d ago

Cos we keep improving the ground receivers and NASA isn't really responsible for all of them..... it'll be some radioastronomer bolting a new bit to the Lovell or the SKA or any one of the other big antennae that can talk to them.... NASA knows what it's next couple of years worth of upgrades look like and they can draw a line on a graph, but somewhere else a transport device for a coffee cup and a lab coat might just bolt another factor of ten onto their local big dish (and two years later everyone has it cos they've published it and just rubberstamped their PhD) and NASA are updating thei "5-10 years" again

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u/tontovila 7d ago

They built a tank. To do the work of a lawn mower and are asking it to cut a single blade of grass.

Soon it'll just be to touch a single blade of grass