to rotate which instruments are switched on ? So: run one for a week, then power it down and run a different one for a week.

Or is it that once powered down some/all instruments cannot be powered back up ?

Not a Voyager scientist so can't speak authoritatively, but one issue I could see here would be that every change/switch/command increases the likelihood of a fault condition arising; much like a lightbulb will burn more or less forever as long as you don't keep turning it off and on.

In that sense it's probably a deliberate decision to have instruments either permanently on, or permanently off.

The worst thing you can do to electronics is to turn them on. The second worst thing is to turn them off again.

So whilst I don't know for sure, I would hazard that they'd probably avoid cycling instruments in case it caused a more terminal fault. Or they powered one down, and the other then didn't power back up, and then the one that was working fine also wouldn't come back, and we lose a working instrument.

They appear instead to be splitting the load between Voyager 1 & 2, so they've knocked off the Voyager 1 CRS, but Voyager 2's is still on, whilst Voyager 2's LECP is getting shut off but Voyager 1's is still going.

Whilst they're both in quite different parts of the sky (V1 above the orbital plane, V2 below), given that we're basically measuring interstellar radiation out there, the data from each probe is probably quite interchangeable (they're not that far outside the solar system), so shutting down instruments in a different order is likely safer (provided power budget allows - one isn't notably higher draw than the other).

Currently fixing bugs in code I've had in daily use for a mere three decades - and it isn't even a twenty three second wait to see the results of the next command!

Deep respect to the guys who made them and those still keeping them going.

I'm lucky if my code makes it through the afternoon.

I make sure my code takes a nap in the afternoon so it's less cranky.

I felt so sad in January when an applicaiton I wrote 14 years ago had to be turned off for good. It'd been running faultlessly for 14 years, probably the most reliable and useful thing I've ever made. But I felt so proud of it though at the same time.

Then I remember Voyager, and if I'm happy over an app lasting 14 years I couldn't imagine what it would feel to be one of the people behind it knowing how long and how well they've lasted.

A beer each for all of them.

I can claim 27 years for code that I know is still running in critical systems (and is still in long term support for 3 years!)

I can claim writing patches for 26 year old OS code and new drivers for a 24 year old version where the hardware has finally had to be replaced.

I can claim 36 years for things running at the Museum of Computing.

What no "grey beard" icon?

"Deep respect to the guys who made them and those still keeping them going."

Those groups are mostly the same people, here is the team after fixing the software last year:

https://d2pn8kiwq2w21t.cloudfront.net/original_images/e1-PIA26275-voyager-copy-16.jpg

They don't write code like they used to. When I were a lad things were meant to last. It was also a simpler time without the many unpredictable layers we have to deal with now. It is very impressive that it's still churning away. Especially when you consider space radiation can really mess stuff up. Just how did they account for that in the code?

"They don't write code like they used to"

Yes they do. The filter of time applied: 99% of everything is garbage and the old stuff you see today is merely what survived longest

One example is victorian housing. The stuff that people point as as "built to last" was specifically built to much higher standards than were normal, mainly for use as low cost housing. The old and ornate piles (mansions) you see have a LOT of issues and need huge amounts of money invested to keep them falling down because for the most part they weren't meant to stand more than 50 years (one place I worked in had the entire back wall bowing by over a foot (3 floors) out due to the builders cutting corners in the 1870s and needed work to keep it standing which would have been more than a new BUILDING)

The classic extreme example is the Brighton Pavilion. It's eggshell fragile due to the cheap and cheerful method of construction but shows the adage that the richer people are, the less they tend to care about longevity (See: Luxury Cars)

I remember seeing the launch of both Voyagers on TV as a teenager at school. I followed every planetary flyby in the National Geographic Magazine. Amazing that the better part of a human lifetime these probes have been speeding through space, collecting loads of data.

I will (again) raise a glass to the team behind this amazing achievement.

"If we don't turn off an instrument on each Voyager now, they would probably have only a few more months of power before we would need to declare end of mission."

These things are powered by RTGs right? And the decay rate of the plutonium therein isn't going to change based on the amount of power being drawn from it, is it? It's not like a battery; the plutonium generates an amount of heat purely based on its decay rate, and the available heat is turned into electricity by thermoelectric converters. So what's actually running out here that's going to last longer if they turn off this instrument? Is it that they wouldn't be able to draw enough current to prevent critical systems from permanently freezing or something?

Power output is reduced by almost 1% per year as the Plutonium decays. The poor old Voyagers are already running on fumes at this point.

if, at the last gasp, just keeping the comms link up would be useful when there is only enough energy for that? No sensors, just a forlorn bleeping at the edge of the solar system to tell us they are still there? Like the retreating bagpiper at a funeral walking off into silence.

I feel strangely sad at this point.

Bloody hell, man... that went into [1]Spirit territory . How can one feel sad for a chunk of metal millions of miles away?

[1] https://xkcd.com/695/