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.

59 thoughts on “NASA Engineers Poke Voyager 1 And Receive Memory Dump

  1. technically those other modes aren’t backups in case something gets corrupted. they’re just other modes.

    the voyager team tried them in hopes that if there is software corruption it is limited to an area that isn’t shared by all of them.

  2. Still floored several decades later by the robustness of the hard and software engineering that went into such a thing. Such durability can’t be taken lightly–this would rightly be called a miracle if it wasn’t so carefully laid out.

    1. They should yeet a shuttle into hyperbolic solar orbit just for fun, as a nice send-off. I wonder how much it would take with our highest-ISP rockets if time is of no issue.

        1. Can’t be done. We don’t have rockets even capable of a miniscule fraction of what the voyager rockets are doing.

          It wasn’t a rocket that got them going that fast. It was a once in several lifetimes alignment of the planets. The rocket merely teed them up.

      1. The largest launch vehicle currently flying (for certain definitions of “flying”) is SpaceX’s Starship. A Starship could theoretically launch a Shuttle orbiter into low Earth orbit along with about 70 tons extra for a boost stage. The highest ISP engine flown so far is the ion engine on the DART mission, with 4190 seconds of specific impulse. With a full tank of xenon using the rest of the available launch mass, it would have a total delta-V of 25,830 m/s. It would only take 8,700 m/s to directly reach solar escape, meaning it would reach an ultimate speed away from the solar system of about 17,000 m/s. This is approximately the same speed that Voyager 1 is currently traveling at, so while it would not fall behind it would not catch up to it either.
        (Of course, it could go faster with gravity assists, but there would also be logistical issues like trying to power an ion engine while on an escape trajectory…)

    2. They were sent out in the 70s. One of them is millions and millions of miles away somewhere outside of our universe, between universes! It won’t come even close to another universe. Interstellar space. The blue dot. So cool

        1. But Soon with the X34 and its 2 pulse engine will get them and bring them back to the Smithsonian. What do you think the X34 has been doing up there for years at a time. I bet if we don’t have light speed yet we will soon.

    1. The Brains of the Voyager Spacecraft: Command, Data, and Attitude Control Computers
      July 09, 2017

      The computers aboard the Voyager probes each have 69.63 kilobytes of memory, total. That’s about enough to store one average internet jpeg file. The probes’ scientific data is encoded on old-fashioned digital 8-track tape machines rather than whatever solid state drive your high-end laptop is currently using. Once it’s been transmitted to Earth, the spacecraft have to write over old data in order to have enough room for new observations.

      The Voyager machines are capable of executing about 81,000 instructions per second. The smart phone that is likely sitting in your pocket is probably about 7,500 times faster than that. They transmit their data back to Earth at 160 bits per second. A slow dial-up connection can deliver at least 20,000 bits per second.

      The Voyager probes are always sending out a signal. Voyager 1 has a 22.4-Watt transmitter – something equivalent to a refrigerator light bulb – but by the time its beacon reaches us, the power has been reduced to roughly 0.1 billion-billionth of a Watt. NASA has to use its largest antenna, a 70-meter dish, or combine two 34-meter antennas, just to hear Voyager.

    2. That these still work is the most amazing to me. Photo of a unit at link:

      November 29, 2018

      The data tape recorder (DTR) system was subcontracted to Lockheed and manufactured by Odetics Corp. The specs show that the machine was a belt driven recorder that used a 1,076′ (328 m) long reel of 1/2″ (12.5 mm) wide magnetic tape which recorded data on eight separate tracks. The DTR could record at two different speeds – 115.2 kbps and 7.2 kbps. Playback topped out at a much slower 57.6 kbps, with 33.6, 21.6, and 7.2 kbps being options as well.

      It appears that none of the non-flown DTRs exist in any museum collections anymore, and all we have is one picture of the mechanism. It’s clearly much more sophisticated than the standard 8-track cartridge transport for consumer use at the time.

      Exactly what the composition of the magnetic tape was, and what secrets were used to prevent it from degrading in the harsh environment of space, are unclear. Odetics, the manufacturer, claimed that the tape would travel through the mechanism a distance of 2,700 mi (4,400 km) before discernible wear.

      It seems to have worked. The DTRs in both spacecraft performed flawlessly from their launch in 1977 and through the entire Grand Tour mission, as well as the extended mission that set both vehicles on a course out of the solar system. In 2007, the DTR in Voyager 1 was shut down for good, not due to any issues with the unit, but because of the dwindling supply of power coming from the craft’s radioisotope thermal generators. As of this writing, the DTR in Voyager 2 is still working, but is likely to be shut down as the power wanes in that vehicle.

      1. “Exactly what the composition of the magnetic tape was, and what secrets were used to prevent it from degrading in the harsh environment of space, are unclear.”

        I’d be that came from a US spysat mission, like this did:

        September 14, 2015
        How a Secret Spy Satellite’s Camera Found a Second Life Mapping the Moon – SAMOS new mission was out of this world.

        Eastman Kodak got the NRO’s permission to offer their SAMOS camera to NASA as part of Boeing’s winning Lunar Orbiter design. For its space odysseys, Eastman Kodak modified the SAMOS camera into a dual-lens configuration adjusted for a lunar orbit of 30 miles altitude.

        Between August 1966 and August 1967, five Lunar Orbiter spacecraft successfully imaged all the landing sites used during the Apollo missions. During their extended missions, they nearly mapped the entire lunar surface—at spy sat resolution. The successful, swiftly-built Lunar Orbiters used off-the-shelf technology. Just how off-the-shelf wasn’t declassified until the 1990s.

        1. That’s supposed to be “I’d bet that came from.” No editing here sucks.

          Here’s another example. The first image of the far side of the moon came from a Soviet probe using the special film captured from one of the 500 US spy balloons sent over their territory: “only about 50 camera gondolas were successfully recovered by the US Air Force. These provided over 10,000 reconnaissance photos of inland Soviet Union and China, including first peeks at nuclear and radar facilities.”:

          Faxes From the Far Side
          The 1950s-era Soviet mission to first photograph the far side of the moon.
          October 2015

          The Soviets recovered a number of the gondolas themselves, and engineers began to dissect them, seeking useful information. To their surprise, they found something inside that happened to solve a little problem they had been having with one of their upcoming space missions: temperature-resistant and radiation-hardened photographic film.

          The specialized film had been necessary in the Genetrix balloons due to the high altitudes involved⁠—up to 100,000 feet. Soviet engineers still didn’t know how the Americans made the film, but that didn’t stop them from repurposing it for their own spacecraft.

    3. The 1988 book “Computers in Spaceflight: The NASA Experience” is about ALL of NASA’s mission computers, crewed & uncrewed. But there’s a section on Voyager’s onboard machine starting on page 177. (Mission control used more sophisticated machines on the ground, of course.) Box 6-1 on page 179 gives an overview of the HYSPACE duplicated attitute control computer (beware Order^H^H Code 66), and page 182 goes into the hardware & software built for the command Flight Data System.

  3. Lets think about this. You guys are proposing to send a system with current technology, far out in spact to catch up with and repair some craft with old technology. If you could get there, why bother to repair the old technology/hardware? You are already there with better hardware and software. Just wave at Voyaget as you pas by and do better science.

  4. I’d love a full writeup of all the hacks and efforts made to keep the voyagers alive. This is one intereseting article but it would be cool to read on all the efforts made

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