Voyager 1 Once Again Returning Science Data From All Four Instruments

As humanity’s furthest reach into the Universe so far, the two Voyager spacecraft’s well-being is of utmost importance to many. Although we know that there will be an end to any science mission, the recent near-death experience by Voyager 1 was a shocking event for many. Now it seems that things may have more or less returned to normal, with all four remaining scientific instruments now back online and returning information.

Since the completion of Voyager 1’s primary mission over 43 years ago, five of its instruments (including the cameras) were disabled to cope with its diminishing power reserves, with two more instruments failing. This left the current magnetometer (MAG), charged particle (LECP) and cosmic ray (CRS) instruments, as well as the plasma wave subsystem (PWS). These are now all back in operation based on the returned science data after the Voyager team confirmed previously that they were receiving engineering data again.

With Voyager 1 now mostly back to normal, some housekeeping is necessary: resynchronizing the onboard time, as well as maintenance on the digital tape recorder. This will ensure that this venerable spacecraft will be all ready for its 47th anniversary this fall.

Thanks to [Mark Stevens] for the tip.

Institutional Memory, On Paper

Our own Dan Maloney has been on a Voyager kick for the past couple of years. Voyager, the space probe. As a long-term project, he has been trying to figure out the computer systems on board. He got far enough to write up a great overview piece, and it’s a pretty good summary of what we know these days. But along the way, he stumbled on a couple old documents that would answer a lot of questions.

Dan asked JPL if they had them, and the answer was “no”. Oddly enough, the very people who are involved in the epic save a couple weeks ago would also like a copy. So when Dan tracked the document down to a paper-only collection at Wichita State University, he thought he had won, but the whole box is stashed away as the library undergoes construction.

That box, and a couple of its neighbors, appear to have a treasure trove of documentation about the Voyagers, and it may even be one-of-a-kind. So in the comments, a number of people have volunteered to help the effort, but I think we’re all just going to have to wait until the library is open for business again. In this age of everything-online, everything-scanned-in, it’s amazing to believe that documents about the world’s furthest-flown space probe wouldn’t be available, but so it is!

It makes you wonder how many other similar documents – products of serious work by the people responsible for designing the systems and machines that shaped our world – are out there in the dark somewhere. History can’t capture everything, and it’s down to our collective good judgement in the end. So if you find yourself in a position to shed light on, or scan, such old papers, please do! And then contact some nerd institution like the Internet Archive or the Computer History Museum.

Welcome Back, Voyager

In what is probably the longest-distance tech support operation in history, the Voyager mission team succeeded in hacking their way around some defective memory and convincing their space probe to send sensor data back to earth again. And for the record, Voyager is a 46-year old system at a distance of now 24 billion kilometers, 22.5 light-hours, from the earth.

While the time delay that distance implies must have made for quite a tense couple days of waiting between sending the patch and finding out if it worked, the age of the computers onboard probably actually helped, in a strange way. Because the code is old-school machine language, one absolutely has to know all the memory addresses where each subroutine starts and ends. You don’t call a function like do_something(); but rather by loading an address in memory and jumping to it.

This means that the ground crew, in principle, knows where every instruction lives. If they also knew where all of the busted memory cells were, it would be a “simple” programming exercise to jump around the bad bits, and re-write all of the subroutine calls accordingly if larger chunks had to be moved. By “simple”, I of course mean “incredibly high stakes, and you’d better make sure you’ve got it right the first time.”

In a way, it’s a fantastic testament to simpler systems that they were able to patch their code around the memory holes. Think about trying to do this with a modern operating system that uses address space layout randomization, for instance. Of course, the purpose there is to make hacking directly on the memory harder, and that’s the opposite of what you’d want in a space probe.

Nonetheless, it’s a testament to careful work and clever software hacking that they managed to get Voyager back online. May she send for another 46 years!

NASA’s Voyager 1 Resumes Sending Engineering Updates To Earth

After many tense months, it seems that thanks to a gaggle of brilliant engineering talent and a lucky break the Voyager 1 spacecraft is once more back in action. Confirmation came on April 20th, when Voyager 1 transmitted its first data since it fell silent on November 14 2023. As previously suspected, the issue was a defective memory chip in the flight data system (FDS), which among other things is responsible for preparing the data it receives from other systems before it is transmitted back to Earth. As at this point in time Voyager 1 is at an approximate 24 billion kilometers distance, this made for a few tense days for those involved.

The firmware patch that got sent over on April 18th contained an initial test to validate the theory, moving the code responsible for the engineering data packaging to a new spot in the FDS memory. If the theory was correct, this should mean that this time the correct data should be sent back from Voyager. Twice a 22.5 hour trip and change through Deep Space and back later on April 20th the team was ecstatic to see what they had hoped for.

With this initial test successful, the team can now move on to moving the remaining code away from the faulty memory after which regular science operations should resume, and giving the plucky spacecraft a new lease on life at the still tender age of 46.

Voyager 1 Issue Tracked Down To Defective Memory Chip

After more than forty-six years all of us are likely to feel the wear of time, and Voyager 1 is no different. Following months of harrowing troubleshooting as the far-flung spacecraft stopped returning sensible data, NASA engineers now feel confident that they have tracked down the cause for the problem: a single defective memory chip. Why this particular chip failed is unknown, but possibilities range from wear and tear to an energetic particle hitting it and disrupting its operation.

We’ve covered the Voyager 1 troubleshooting saga so far, with the initial garbled responses attributed to a range of systems, but narrowed down to the Flight Data Subsystem (FDS), which prepares data for transmission by the telemetry modulation unit (TMU). Based on a recent ‘poke’ command that returned a memory dump engineers concluded that the approximately 3% of corrupted data fit with this one memory chip, opening the possibility of a workaround.

Recently NASA engineers have also been working on patching up the firmware in both Voyager spacecraft, against the background of the dwindling energy produced by the radioisotope generators that have kept both spacecraft powered and warm, even in the cold, dark depths of Deep Space far beyond the light of our Sun.

NASA Engineers Poke Voyager 1 And Receive Memory Dump

For months, there has been a rising fear that we may have to say farewell to the Voyager 1 spacecraft after it began to send back garbled data. Now, in a sudden twist, Voyager 1 sent back a read-out of the Flight Data Subsystem (FDS) memory after a “poke” command, which both gives some hope that the spacecraft is in a better condition than feared while also allows engineers to dig through the returned memory read-out for clues. Although this data was not sent in the format that the FDS is supposed to use when it’s working correctly, it’s nevertheless readable.

It was previously suspected that the issue lay with the telemetry modulation unit (TMU), but has since been nailed down to the FDS itself.  This comes after NASA engineers have been updating the firmware on both spacecraft to extend their lifespan, but it’s too early to consider this as a possible reason. Now, as a result of the “poke” instruction – which commands the computer to try different sequences in its firmware in case part of it has been corrupted – engineers can compare it to previous downloads to hopefully figure out the cause behind the FDS problems and a possible solution.

Inspired by this news of the decoded memory download, Nadia Drake – daughter of Frank Drake – wrote about how it affects not only the engineers who have worked on the Voyager mission for the past decades but also her own thoughts about the two Voyager spacecraft. Not only do they form a lasting reminder of her father and so many of his colleagues, but the silence that would follow if we can no longer communicate with these spacecraft would be profound. Still, this new hope is better than the earlier news about this plucky little spaceship.

Thanks to [Mark Stevens] for the tip.

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Hackaday Links: March 10, 2024

We all know that we’re living in a surveillance state that would make Orwell himself shake his head, but it looks like at least one company in this space has gone a little rogue. According to reports, AI surveillance start-up Flock <<insert gratuitous “What the Flock?” joke here>> has installed at least 200 of its car-tracking cameras on public roads in South Carolina alone. That’s a serious whoopsie, especially since it’s illegal to install anything on state infrastructure without permission, which it appears Flock failed to obtain. South Carolina authorities are making a good show of being outraged about this, but it sort of rings hollow to us, especially since Flock now claims that 70% of the population (of the USA, we presume) is covered by their technology. Also, police departments across the country are in love with Flock’s service, which lets them accurately track the movements of potential suspects, which of course is everyone. No word on whether Flock will have to remove the rogue cameras, but we’re not holding our breath.

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