11 ms·

Voyager 2 is back online after eight months of radio silence

529 points by sohkamyung 6y ago

teraflop 6y ago
I don't think the Register's headline is very accurate. The probe itself remained online, and there was plenty of radio communication happening during that period; it was just one-way, from Voyager 2 to Earth. From NASA's press release: > The call to Voyager 2 was a test of new hardware recently installed on Deep Space Station 43, the only dish in the world that can send commands to Voyager 2. ... Since the dish went offline, mission operators have been able to receive health updates and science data from Voyager 2, but they haven't been able to send commands to the far-flung probe, which has traveled billions of miles from Earth since its 1977 launch. https://www.nasa.gov/feature/jpl/nasa-contacts-voyager-2-using-upgraded-deep-space-network-dish https://www.nasa.gov/feature/jpl/nasa-contacts-voyager-2-usi...
- _trampeltier 6y ago
  Yes, there was even some new lately. "Voyager Spacecraft Detect an Increase in The Density of Space Outside The Solar System" https://news.ycombinator.com/item?id=24826155 https://news.ycombinator.com/item?id=24826155 Dave Jones made a coupe of videos about the Deep Space Station in Canberra. https://m.youtube.com/watch?v=FzRP1qdwPKw https://m.youtube.com/watch?v=FzRP1qdwPKw
superasn 6y ago
I was just reading the pale blue dot and he mentions that Voyager 2’s scan platform jammed after its encounter with Saturn. Voyager 2 emerged from behind Saturn (as seen from the Earth) in August 1981. The scan platform had been moving feverishly—pointing here and there among the rings, moons, and the planet itself during the all-too-brief moments of close approach. Suddenly, the platform jammed. A stuck scan platform is a maddening predicament: knowing that the spacecraft is flying past wonders that have never been witnessed, that we will not see again for years or decades, and the incurious spacecraft staring fixedly off into space, ignoring everything. The scan platform is driven by actuators containing gear trains. So first the JPL engineers ran an identical copy of a flight actuator in a simulated mission. This actuator failed after 348 turns; the actuator on the spacecraft had failed after 352 turns. The problem turned out to be a lubrication failure. Good to know, but what to do about it? Plainly, it would be impossible to overtake Voyager with an oilcan. The engineers wondered whether they could restart the failed actuator by alternate heating and cooling; maybe the resulting thermal stresses would induce the components of the actuator to expand and contract at different rates and unjam the system. They tested this notion with specially manufactured actuators in the laboratory, and then jubilantly found that in this way they could start the scan platform up again in space. Project personnel also devised ways to diagnose any additional trend toward actuator failure early enough to work around the problem. Thereafter, Voyager 2’s scan platform worked perfectly. All the pictures taken in the Uranus and Neptune systems owe their existence to this work. The engineers had saved the day again. Our hacks are nothing compared to the hacks of these old school nasa programmers :)
- onion2k 6y ago
  Our hacks are nothing compared to the hacks of these old school nasa programmers :) The amazing thing (to me) is that they developed the Voyager spacecraft in an era when space flight wasn't hugely popular and the budgets at NASA were being cut regularly. NASA went from a peak of $6bn a year in the mid-sixties under Johnson to almost half that under Ford and Nixon. The engineers were well-respected and they clearly felt the work was important, but they weren't particularly well paid. They did this for the love and the science.
  - brazzy 6y ago
    It's great, but hardly amazing. Most academic research is done by underpaid PhD and postdoc students for the love of science, and most of that is far less glamorous than SPACE.
    - abhayhegde 6y ago
      I believe the aspect of beauty and glamor is a matter of taste and hence very subjective. Maybe some projects may turn out to be less influential, but nevertheless it appeals to a particular community.
    - part1of2 6y ago
      > Most academic research is done by underpaid PhD and postdoc students for the love of science I’d hardly call the graduate papers coming out of academia equivalent to the level of innovation & creativity of what the engineers above described. Perhaps they’re both underpaid, but one is certainly more amazing. Hardly the same.
      - matthewdgreen 6y ago
        You should read Rhodes’ “The Making of the Atomic Bomb” if you want to understand what incredible engineering feats academic scientists are capable of — when the people are tightly focused on achieving a single goal. You should also read Rhodes’ book if you want to understand why unguided fundamental scientific research itself is so critical, even when it doesn’t immediately seem useful to you: without the discoveries of science, nuclear fission wouldn’t have been understood. (Of course, many will disagree that the development atomic bomb is a good outcome, but that’s a very different conversation.)
NiceWayToDoIT 6y ago
"The probe launched on August 20th 1977, but is still just seventeen light-hours away" 43 years for 0.00194 light years... makes me feel :( huh ... and nearest star Proxima Centauri is 4.2441 light years away ... :/
- Cthulhu_ 6y ago
  Interstellar travel, unless there's a revolution in propulsion, is unlikely to happen I think. I'm sure that at some point they'll send up another probe with more fuel to go out faster, but it's not going to be revolutionary.
  - metiscus 6y ago
    The tech has existed at least theoretically since the 60s but nobody is willing to use it. https://en.m.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.m.wikipedia.org/wiki/Project_Orion_(nuclear_propu...
    - deleted 6y ago
      [deleted]
    - jacobwilliamroy 6y ago
      Check out Hardtack Teak. It was an exo-atmospheric nuclear test above Johnston Atoll. The blast was visible from Honolulu and a large glowing red cloud drifted over the island chain all the way from Johnston Atoll. There are areas of the zone underneath the explosion which are still hot to this day. And that was just one of the tests that went right. There were plenty of failures too, both in atmosphere and on the launchpad, which spread nuclear material and toxic fuel all over the place. High-altitude nuclear explosions are definitely a threat to humanity, no doubt about it.
      - m4rtink 6y ago
        Well, you don't necessarily need to launch from Earth - starting an Orion mission from say high lunar orbit should be perfectly safe.
walrus01 6y ago
If you've ever replaced a Ku or Ka band feed horn on a 1.2 to 1.8 meter size VSAT dish, looking at a three ton feed horn is an interesting thing to wrap your mind around.
delsarto 6y ago
Richard Stephenson works in operations at the site of the antenna mentioned and sometimes gives some "behind the scenes" views, worth a follow https://twitter.com/nascom1 https://twitter.com/nascom1 An older tour discussing how to contact Voyager 2 he gave at https://www.eevblog.com/2017/04/19/how-to-contact-the-voyager-2-probe-part-1/ https://www.eevblog.com/2017/04/19/how-to-contact-the-voyage...
deleted 6y ago
[deleted]
pg_bot 6y ago
Voyager 2 You're leading the rescue Send help soon Well I've seen spirits and children all waiting, waiting for you They're all waiting for you https://www.youtube.com/watch?v=Ud0K0eS8EyU https://www.youtube.com/watch?v=Ud0K0eS8EyU
pvaldes 6y ago
Lets imagine... hypothetically [1] that we could design a new kind of space oriented machines, sort of a "spatial server" or a "telephone repeater", that could be left in Pluto (or an asteroid, or orbiting Saturn, whatever...), and be designed to take this weak signals, amplify it, and resend it to the earth Would this help to increase the range of what discover can report and... hum, discover? Would help us to have the info in two months instead in eight? (maybe splitting in a multipart message and broadcasting in several threads and different frequency bands at the same time or so?). or would be basically useless? Could be used to start a exploring outer web that would be improved with each new launching as other countries connect to it? [1] I don't know how realistic, or technically difficult would be. Is an idea idea that just occurred to me
- roter 6y ago
  I like it. You'd need (many) more than one. Pluto has an orbit of 248 years. Kind of like putting your wifi router on a train track on your property line and sharing with your neighbours. Perhaps on a bunch of objects at Lagrange points [0]? [0] https://en.wikipedia.org/wiki/List_of_objects_at_Lagrange_points https://en.wikipedia.org/wiki/List_of_objects_at_Lagrange_po...
- arbitrage 6y ago
  That's exactly how the Soviets pulled off the geopolitical coup of broadcasting images from the dark side of the moon back to earth. They pulled it off first, because they were clever about it. What you are proposing will absolutely work. Imagine a self-routing datagram trying to get closer to its destination at each step. In fact, that's exactly how the Internet is designed. Self-healing, self-routing, best-effort. Chop messages up into little pieces, and send them off to their destination, and hope for the best that they'll be reassembled correctly at the destination.
- secondcoming 6y ago
  Interplanetary Internet [0] When I first heard about the Deep Space Network I thought it was something like this, and not a bunch of dishes on Earth. [0]https://en.wikipedia.org/wiki/Interplanetary_Internet https://en.wikipedia.org/wiki/Interplanetary_Internet
Jaruzel 6y ago
Absolutely NOT the same dish, but if you've not seen this film, you are missing out: The Dish: https://www.imdb.com/title/tt0205873/ https://www.imdb.com/title/tt0205873/
Max-q 6y ago
After reading the article, I would chosen the headline "Earth is back online after eight months of radio slience". The earth station was down, not Voyager ;-)
- ThinkingGuy 6y ago
  I seem to recall from the documentary "The Farthest" that Voyager actually transmits data almost continuously, but that most of it is lost forever because the capable ground stations are only ever tuned to it for brief, scheduled windows.
eminence32 6y ago
I know it's the year 2020 and we're capable of some amazing technical feats, but for some reasons the fact that we can have bidirectional communication with something so old and so far away is astounding to me.
- sjm-lbm 6y ago
  Over the course of my life, I feel like I've read the "Voyager is going to go out of communication range/Voyager has gone out of communication range/Wait, no, they figured something out" series of stories several times. It's amazing, and it makes me happy every time.
  - MauranKilom 6y ago
    Of course there's a related xkcd: https://xkcd.com/1189/ https://xkcd.com/1189/
- deleted 6y ago
  [deleted]
shireboy 6y ago
"Which will be just in time for the arrival of the Perseverance Rover on Mars, another mission DSS43 will handle" Wait, so they sent Perserverance on it's way to Mars without comms in the southern hemisphere? Or is this a backup?
- Denvercoder9 6y ago
  The Mars rovers, including Perserverance, usually communicate directly over a high-speed link with one of several relay satellites orbiting Mars. The smaller antennas of the DSN can communicate with the relay satellites as well. Furthermore, the locations of the stations aren't determined by the hemispheres. Everything DSN is used for is far enough away from Earth that it doesn't matter if the antenna is in the northern or southern hemisphere. The reason for the spread-out stations is the rotation of the Earth, which for half of the day puts the Earth in between the station and the satellite.
  - dr_orpheus 6y ago
    While the rotation of the earth is one of the primary reasons for the spacing, the hemisphere does matter for Voyager. From the article: "As Voyager 2 is heading southwards compared to Earth's orbital plane, only a dish south of the equator can send the probe a sufficiently powerful signal."
    - Denvercoder9 6y ago
      True, but that's mostly an issue because the construction of the antennas have a minimum elevation limit.
      - dr_orpheus 6y ago
        Not necessarily, Voyager 2 is pretty far angled below the ecliptic plane by 48 degrees [1]. If you were to point the Goldstone dish (35 degree N latitude) directly at the horizon you can reach as far as ~78 degrees below the ecliptic plane if you are pointing in the direction of the tilt of the earth (I don't actually know where Voyager is relative to the tilt of the Earth). If it were in the opposite direction, pointing the antenna at the horizon means you could only point at something ~32 degrees below the ecliptic. And Madrid has a slightly higher latitude at 40 deg N. [1] https://voyager.jpl.nasa.gov/frequently-asked-questions/fact-sheet/ https://voyager.jpl.nasa.gov/frequently-asked-questions/fact...
NKosmatos 6y ago
It's only fitting to put a link to the Deep Space Network (DSN), displaying what all the dishes are doing right now (spacecrafts, data rates...): https://eyes.nasa.gov/dsn/dsn.html https://eyes.nasa.gov/dsn/dsn.html
jabofh 6y ago
"What's wrong?" "Nothing." "No, really, what's wrong?" "I said 'nothing'!" "Okay, So when you're ready, talk to me..." ... Eight months later...
moomin 6y ago
Message sent back was "Is this all I am? Is there nothing more?"
janee 6y ago
Makes me wonder about the effort put into the design of it's longevity. It must be an awesome feeling if you worked on it and so many years later there's still tangible value being extracted from it

529 points by sohkamyung 6y ago

I don't think the Register's headline is very accurate. The probe itself remained online, and there was plenty of radio communication happening during that period; it was just one-way, from Voyager 2 to Earth. From NASA's press release: > The call to Voyager 2 was a test of new hardware recently installed on Deep Space Station 43, the only dish in the world that can send commands to Voyager 2. ... Since the dish went offline, mission operators have been able to receive health updates and science data from Voyager 2, but they haven't been able to send commands to the far-flung probe, which has traveled billions of miles from Earth since its 1977 launch. https://www.nasa.gov/feature/jpl/nasa-contacts-voyager-2-using-upgraded-deep-space-network-dish https://www.nasa.gov/feature/jpl/nasa-contacts-voyager-2-usi...

_trampeltier 6y ago
Yes, there was even some new lately. "Voyager Spacecraft Detect an Increase in The Density of Space Outside The Solar System" https://news.ycombinator.com/item?id=24826155 https://news.ycombinator.com/item?id=24826155 Dave Jones made a coupe of videos about the Deep Space Station in Canberra. https://m.youtube.com/watch?v=FzRP1qdwPKw https://m.youtube.com/watch?v=FzRP1qdwPKw

superasn 6y ago

I was just reading the pale blue dot and he mentions that Voyager 2’s scan platform jammed after its encounter with Saturn. Voyager 2 emerged from behind Saturn (as seen from the Earth) in August 1981. The scan platform had been moving feverishly—pointing here and there among the rings, moons, and the planet itself during the all-too-brief moments of close approach. Suddenly, the platform jammed. A stuck scan platform is a maddening predicament: knowing that the spacecraft is flying past wonders that have never been witnessed, that we will not see again for years or decades, and the incurious spacecraft staring fixedly off into space, ignoring everything. The scan platform is driven by actuators containing gear trains. So first the JPL engineers ran an identical copy of a flight actuator in a simulated mission. This actuator failed after 348 turns; the actuator on the spacecraft had failed after 352 turns. The problem turned out to be a lubrication failure. Good to know, but what to do about it? Plainly, it would be impossible to overtake Voyager with an oilcan. The engineers wondered whether they could restart the failed actuator by alternate heating and cooling; maybe the resulting thermal stresses would induce the components of the actuator to expand and contract at different rates and unjam the system. They tested this notion with specially manufactured actuators in the laboratory, and then jubilantly found that in this way they could start the scan platform up again in space. Project personnel also devised ways to diagnose any additional trend toward actuator failure early enough to work around the problem. Thereafter, Voyager 2’s scan platform worked perfectly. All the pictures taken in the Uranus and Neptune systems owe their existence to this work. The engineers had saved the day again. Our hacks are nothing compared to the hacks of these old school nasa programmers :)

onion2k 6y ago
Our hacks are nothing compared to the hacks of these old school nasa programmers :) The amazing thing (to me) is that they developed the Voyager spacecraft in an era when space flight wasn't hugely popular and the budgets at NASA were being cut regularly. NASA went from a peak of $6bn a year in the mid-sixties under Johnson to almost half that under Ford and Nixon. The engineers were well-respected and they clearly felt the work was important, but they weren't particularly well paid. They did this for the love and the science.
- brazzy 6y ago
  It's great, but hardly amazing. Most academic research is done by underpaid PhD and postdoc students for the love of science, and most of that is far less glamorous than SPACE.
  - abhayhegde 6y ago
    I believe the aspect of beauty and glamor is a matter of taste and hence very subjective. Maybe some projects may turn out to be less influential, but nevertheless it appeals to a particular community.
  - part1of2 6y ago
    > Most academic research is done by underpaid PhD and postdoc students for the love of science I’d hardly call the graduate papers coming out of academia equivalent to the level of innovation & creativity of what the engineers above described. Perhaps they’re both underpaid, but one is certainly more amazing. Hardly the same.
    - matthewdgreen 6y ago
      You should read Rhodes’ “The Making of the Atomic Bomb” if you want to understand what incredible engineering feats academic scientists are capable of — when the people are tightly focused on achieving a single goal. You should also read Rhodes’ book if you want to understand why unguided fundamental scientific research itself is so critical, even when it doesn’t immediately seem useful to you: without the discoveries of science, nuclear fission wouldn’t have been understood. (Of course, many will disagree that the development atomic bomb is a good outcome, but that’s a very different conversation.)

NiceWayToDoIT 6y ago

"The probe launched on August 20th 1977, but is still just seventeen light-hours away" 43 years for 0.00194 light years... makes me feel :( huh ... and nearest star Proxima Centauri is 4.2441 light years away ... :/

Cthulhu_ 6y ago
Interstellar travel, unless there's a revolution in propulsion, is unlikely to happen I think. I'm sure that at some point they'll send up another probe with more fuel to go out faster, but it's not going to be revolutionary.
- metiscus 6y ago
  The tech has existed at least theoretically since the 60s but nobody is willing to use it. https://en.m.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.m.wikipedia.org/wiki/Project_Orion_(nuclear_propu...
  - deleted 6y ago
    [deleted]
  - jacobwilliamroy 6y ago
    Check out Hardtack Teak. It was an exo-atmospheric nuclear test above Johnston Atoll. The blast was visible from Honolulu and a large glowing red cloud drifted over the island chain all the way from Johnston Atoll. There are areas of the zone underneath the explosion which are still hot to this day. And that was just one of the tests that went right. There were plenty of failures too, both in atmosphere and on the launchpad, which spread nuclear material and toxic fuel all over the place. High-altitude nuclear explosions are definitely a threat to humanity, no doubt about it.
    - m4rtink 6y ago
      Well, you don't necessarily need to launch from Earth - starting an Orion mission from say high lunar orbit should be perfectly safe.

walrus01 6y ago

If you've ever replaced a Ku or Ka band feed horn on a 1.2 to 1.8 meter size VSAT dish, looking at a three ton feed horn is an interesting thing to wrap your mind around.

delsarto 6y ago

Richard Stephenson works in operations at the site of the antenna mentioned and sometimes gives some "behind the scenes" views, worth a follow https://twitter.com/nascom1 https://twitter.com/nascom1 An older tour discussing how to contact Voyager 2 he gave at https://www.eevblog.com/2017/04/19/how-to-contact-the-voyager-2-probe-part-1/ https://www.eevblog.com/2017/04/19/how-to-contact-the-voyage...

deleted 6y ago

[deleted]

pg_bot 6y ago

Voyager 2 You're leading the rescue Send help soon Well I've seen spirits and children all waiting, waiting for you They're all waiting for you https://www.youtube.com/watch?v=Ud0K0eS8EyU https://www.youtube.com/watch?v=Ud0K0eS8EyU

pvaldes 6y ago

Lets imagine... hypothetically [1] that we could design a new kind of space oriented machines, sort of a "spatial server" or a "telephone repeater", that could be left in Pluto (or an asteroid, or orbiting Saturn, whatever...), and be designed to take this weak signals, amplify it, and resend it to the earth Would this help to increase the range of what discover can report and... hum, discover? Would help us to have the info in two months instead in eight? (maybe splitting in a multipart message and broadcasting in several threads and different frequency bands at the same time or so?). or would be basically useless? Could be used to start a exploring outer web that would be improved with each new launching as other countries connect to it? [1] I don't know how realistic, or technically difficult would be. Is an idea idea that just occurred to me

roter 6y ago
I like it. You'd need (many) more than one. Pluto has an orbit of 248 years. Kind of like putting your wifi router on a train track on your property line and sharing with your neighbours. Perhaps on a bunch of objects at Lagrange points [0]? [0] https://en.wikipedia.org/wiki/List_of_objects_at_Lagrange_points https://en.wikipedia.org/wiki/List_of_objects_at_Lagrange_po...
arbitrage 6y ago
That's exactly how the Soviets pulled off the geopolitical coup of broadcasting images from the dark side of the moon back to earth. They pulled it off first, because they were clever about it. What you are proposing will absolutely work. Imagine a self-routing datagram trying to get closer to its destination at each step. In fact, that's exactly how the Internet is designed. Self-healing, self-routing, best-effort. Chop messages up into little pieces, and send them off to their destination, and hope for the best that they'll be reassembled correctly at the destination.
secondcoming 6y ago
Interplanetary Internet [0] When I first heard about the Deep Space Network I thought it was something like this, and not a bunch of dishes on Earth. [0]https://en.wikipedia.org/wiki/Interplanetary_Internet https://en.wikipedia.org/wiki/Interplanetary_Internet

Jaruzel 6y ago

Absolutely NOT the same dish, but if you've not seen this film, you are missing out: The Dish: https://www.imdb.com/title/tt0205873/ https://www.imdb.com/title/tt0205873/

Max-q 6y ago

After reading the article, I would chosen the headline "Earth is back online after eight months of radio slience". The earth station was down, not Voyager ;-)

ThinkingGuy 6y ago
I seem to recall from the documentary "The Farthest" that Voyager actually transmits data almost continuously, but that most of it is lost forever because the capable ground stations are only ever tuned to it for brief, scheduled windows.

eminence32 6y ago

I know it's the year 2020 and we're capable of some amazing technical feats, but for some reasons the fact that we can have bidirectional communication with something so old and so far away is astounding to me.

sjm-lbm 6y ago
Over the course of my life, I feel like I've read the "Voyager is going to go out of communication range/Voyager has gone out of communication range/Wait, no, they figured something out" series of stories several times. It's amazing, and it makes me happy every time.
- MauranKilom 6y ago
  Of course there's a related xkcd: https://xkcd.com/1189/ https://xkcd.com/1189/
deleted 6y ago
[deleted]

shireboy 6y ago

"Which will be just in time for the arrival of the Perseverance Rover on Mars, another mission DSS43 will handle" Wait, so they sent Perserverance on it's way to Mars without comms in the southern hemisphere? Or is this a backup?

Denvercoder9 6y ago
The Mars rovers, including Perserverance, usually communicate directly over a high-speed link with one of several relay satellites orbiting Mars. The smaller antennas of the DSN can communicate with the relay satellites as well. Furthermore, the locations of the stations aren't determined by the hemispheres. Everything DSN is used for is far enough away from Earth that it doesn't matter if the antenna is in the northern or southern hemisphere. The reason for the spread-out stations is the rotation of the Earth, which for half of the day puts the Earth in between the station and the satellite.
- dr_orpheus 6y ago
  While the rotation of the earth is one of the primary reasons for the spacing, the hemisphere does matter for Voyager. From the article: "As Voyager 2 is heading southwards compared to Earth's orbital plane, only a dish south of the equator can send the probe a sufficiently powerful signal."
  - Denvercoder9 6y ago
    True, but that's mostly an issue because the construction of the antennas have a minimum elevation limit.
    - dr_orpheus 6y ago
      Not necessarily, Voyager 2 is pretty far angled below the ecliptic plane by 48 degrees [1]. If you were to point the Goldstone dish (35 degree N latitude) directly at the horizon you can reach as far as ~78 degrees below the ecliptic plane if you are pointing in the direction of the tilt of the earth (I don't actually know where Voyager is relative to the tilt of the Earth). If it were in the opposite direction, pointing the antenna at the horizon means you could only point at something ~32 degrees below the ecliptic. And Madrid has a slightly higher latitude at 40 deg N. [1] https://voyager.jpl.nasa.gov/frequently-asked-questions/fact-sheet/ https://voyager.jpl.nasa.gov/frequently-asked-questions/fact...

NKosmatos 6y ago

It's only fitting to put a link to the Deep Space Network (DSN), displaying what all the dishes are doing right now (spacecrafts, data rates...): https://eyes.nasa.gov/dsn/dsn.html https://eyes.nasa.gov/dsn/dsn.html

jabofh 6y ago

"What's wrong?" "Nothing." "No, really, what's wrong?" "I said 'nothing'!" "Okay, So when you're ready, talk to me..." ... Eight months later...

moomin 6y ago

Message sent back was "Is this all I am? Is there nothing more?"

janee 6y ago

Makes me wonder about the effort put into the design of it's longevity. It must be an awesome feeling if you worked on it and so many years later there's still tangible value being extracted from it