7 ms·

Zombie Satellites Return from the Graveyard

79 points by sohkamyung 6y ago

ethagnawl 6y ago
This area of research and application is fascinating and, as the article alludes, will only become more important in the coming decades. I also read a related story[0] recently that others may find of interest: A hobbyist was able to track down a satellite whose EOL was supposed to be in _1972_ by using a beefed up HAM radio to scour the sky for its RF. [0] - https://www.npr.org/2020/04/24/843493304/long-lost-u-s-military-satellite-found-by-amateur-radio-operator https://www.npr.org/2020/04/24/843493304/long-lost-u-s-milit...
mhandley 6y ago
There really needs to be mandatory insurance for GEO satellites. If your satellite fails to reach the graveyard orbit, the insurance pays the towing fees.
- RandomBacon 6y ago
  Reminds me of the series Planetes. I would definitely be a garbage man if it meant working space and EVAs.
  - sohkamyung 6y ago
    Not quite the same, but I'm reminded of the short lived show "Salvage 1", starring Andy Griffith [1] [1] https://en.wikipedia.org/wiki/Salvage_1 https://en.wikipedia.org/wiki/Salvage_1
    - joshstrange 6y ago
      Interesting, I hate that these types of shows appear to be lost to the ages. I can't find it to buy (there are a handful of episodes available for purchase on DVD on Amazon for something like $17/per) and I don't see it come up on streaming services either.
    - dhosek 6y ago
      I loved that show when I was a kid. The science was pretty bad, but the stories were great.
  - deleted 6y ago
    [deleted]
  - robotmay 6y ago
    One of my all-time favourite sci-fi shows. The setting manages to mix the banal and the excitement of space so well.
  - drybjed 6y ago
    In that case you might be interested in Hardspace: Shipbreaker[1] game which is currently in early access. There are some gameplay videos already, for example Scott Manley's[2]. [1]: https://hardspace-shipbreaker.com/ https://hardspace-shipbreaker.com/ [2]: https://www.youtube.com/watch?v=kj0FKs7l8sA https://www.youtube.com/watch?v=kj0FKs7l8sA
walrus01 6y ago
One of the things persons not involved in the industry find interesting, is that in the entire history of manned spaceflight, no human has ever visited geostationary orbit. I have talked to a number of people who were mistakenly under the impression that humans occasionally conduct repairs on telecom satellites. Also this is the first time a (non-classified, that we know about) spacecraft has visited and photographed another satellite in geostationary orbit.
- Robotbeat 6y ago
  Humans have done something like repairs on telecom satellites... If they got stuck in LEO before insertion to GEO. Also, ISS.
  - walrus01 6y ago
    Very, very rarely and at ridiculous cost ($900m+ per launch) by space shuttle in the 1980s as publicity stunts, nothing more.
    - WalterBright 6y ago
      The space telescope got several repair and upgrade missions. Since the R+D cost of developing the telescope was already spent, it's hard to believe the incremental cost of building and launching another one would have cost more than a shuttle mission.
      - walrus01 6y ago
        LEO is a very, very different thing in terms of exo-atmospheric delta v budget than achieving a circular Geostationary distance orbit with a manned craft.
        Cthulhu_ 6y ago
        Which is why I really hope the new space telescope will work, since they can't realistically go out there to fix it.
gruez 6y ago
>Graveyard orbits comprise paths at least 300 kilometers above the geosynchronous region, giving the zombie spacecraft room to have their orbits incrementally ground down by the gravity of the sun and moon. Why is the graveyard orbit higher than the orbit for operating satellites? Doesn't that mean when the orbit eventually decays, that the satellite will eventually fall back into the orbit where all the operating satellites are?
- nine_k 6y ago
  Likely to let these satellites not interfere with the operational satellites right now, and for many decades? Also, the higher the orbit, the more room it has, and the longer it takes to fall from it onto the planet. Maybe we'll be collecting these satellites after these few decades pass, and use them for something.
- walrus01 6y ago
  At Geostationary distances, there is so little in the way of atmospheric molecules that orbits will not decay over a geological time scale. Humankind could nuke itself into near oblivion, revert to the stone age and rediscover spaceflight in 20,000 years from now and those satellites would still be up there at just about the same altitude. It's very different in terms of atmospheric drag compared to orbits under 1500km.
- savrajsingh 6y ago
  I get the impression it’s easier to go for a bigger orbit than deorbit when you’re at GEO.
- Rebelgecko 6y ago
  There's not much going on above GEO, so there's little risk of hitting someone else if/when you lose control of the sat. Orbital decay is pretty minimal at that level.
- m4rtink 6y ago
  I guess to prevent dead satellites interferring with new ones comming to GEO from below ? Not sure if that's right though as many GEO insertion orbits often have apogeum much higher than the final GEO altitude.
erwinh 6y ago
Lots of material up there, would be interesting to prospect what more tech could be appropriated there for new use-cases. At https://space-search.io https://space-search.io by applying the orbit duration filter lower than 1 (i.e. above geostationary) you can get a good picture of all the satellites currently in that kind of graveyard orbit.
raxxorrax 6y ago
I don't quite understand why they don't decrease their orbit to burn up in the atmosphere. It would certainly be the Kerbal way. Are the satelites too large to burn up?
- Monroe13 6y ago
  According to some Wikipedia research “De-orbiting a geostationary satellite requires a delta-v of about 1,500 metres per second (4,900 ft/s), whereas re-orbiting it to a graveyard orbit only requires about 11 metres per second (36 ft/s).” https://en.m.wikipedia.org/wiki/Graveyard_orbit https://en.m.wikipedia.org/wiki/Graveyard_orbit
  - raxxorrax 6y ago
    Huh, wouldn't have guessed it to be that much, but it makes sense. De-orbiting gets cheaper the higher your orbit is and a geo stationary orbit is high, but not that high.
- gameswithgo 6y ago
  requires a huge amount of fuel for a geo-stat-sat to get back down.
- xenophonf 6y ago
  The Kerbal way is to remember that to lower your orbit, you have to slow down, and to slow down requires propellant. You're moving really, really fast in a geosync orbit, so slowing down to lithobrake your satellite would require a _lot_ of propellant. Conversely, to raise your orbit, you have to speed up. And since you're only going up a little bit, you only need a little bit of propellant.
- walrus01 6y ago
  While theoretically possible, it is a lot easier to put a "spare" 1500-2000m/s of delta v and fuel tankage on a Kerbal spacecraft than in real life. Unless we invent a magical ion thruster with a specific impulse of 30000 nobody is going to put enough fuel on a Geostationary telecom satellite to lower its perigee below 100km at EOL. That same fuel is better used for station keeping and to extend its service life.
saul_goodman 6y ago
I'll just leave this here: http://orbitofshame.org http://orbitofshame.org
dekhn 6y ago
A neighbor of mine worked on the refuelling mission described here. Basically he uses a library of CAD designs to assemble standardized components for satellites. The more I learn about satellite operations the more impressed I get. My favorite was a zombie satellite that woke up after 25+ years and started transmitting again. Apparently, the solar panels had broken in such a way that they transmitted power through the battery (even though the battery could no longer hold a charge), so periodically the satellite would be in illumination and transmit (but it had a very weird pattern because the satellite was spinning out of control). It still blows me away that most satellites, if they have a glitch like losing contact with the ground, will go into "Safe" mode- solar panels fully deployed, directly facing the sun, so it's likely there's enough power to recontact. I have enough trouble implementing a PID-driven motor on my arduino that it impressed me what people can do in space.

79 points by sohkamyung 6y ago

This area of research and application is fascinating and, as the article alludes, will only become more important in the coming decades. I also read a related story[0] recently that others may find of interest: A hobbyist was able to track down a satellite whose EOL was supposed to be in _1972_ by using a beefed up HAM radio to scour the sky for its RF. [0] - https://www.npr.org/2020/04/24/843493304/long-lost-u-s-military-satellite-found-by-amateur-radio-operator https://www.npr.org/2020/04/24/843493304/long-lost-u-s-milit...

mhandley 6y ago

There really needs to be mandatory insurance for GEO satellites. If your satellite fails to reach the graveyard orbit, the insurance pays the towing fees.

RandomBacon 6y ago
Reminds me of the series Planetes. I would definitely be a garbage man if it meant working space and EVAs.
- sohkamyung 6y ago
  Not quite the same, but I'm reminded of the short lived show "Salvage 1", starring Andy Griffith [1] [1] https://en.wikipedia.org/wiki/Salvage_1 https://en.wikipedia.org/wiki/Salvage_1
  - joshstrange 6y ago
    Interesting, I hate that these types of shows appear to be lost to the ages. I can't find it to buy (there are a handful of episodes available for purchase on DVD on Amazon for something like $17/per) and I don't see it come up on streaming services either.
  - dhosek 6y ago
    I loved that show when I was a kid. The science was pretty bad, but the stories were great.
- deleted 6y ago
  [deleted]
- robotmay 6y ago
  One of my all-time favourite sci-fi shows. The setting manages to mix the banal and the excitement of space so well.
- drybjed 6y ago
  In that case you might be interested in Hardspace: Shipbreaker[1] game which is currently in early access. There are some gameplay videos already, for example Scott Manley's[2]. [1]: https://hardspace-shipbreaker.com/ https://hardspace-shipbreaker.com/ [2]: https://www.youtube.com/watch?v=kj0FKs7l8sA https://www.youtube.com/watch?v=kj0FKs7l8sA

walrus01 6y ago

One of the things persons not involved in the industry find interesting, is that in the entire history of manned spaceflight, no human has ever visited geostationary orbit. I have talked to a number of people who were mistakenly under the impression that humans occasionally conduct repairs on telecom satellites. Also this is the first time a (non-classified, that we know about) spacecraft has visited and photographed another satellite in geostationary orbit.

Robotbeat 6y ago
Humans have done something like repairs on telecom satellites... If they got stuck in LEO before insertion to GEO. Also, ISS.
- walrus01 6y ago
  Very, very rarely and at ridiculous cost ($900m+ per launch) by space shuttle in the 1980s as publicity stunts, nothing more.
  - WalterBright 6y ago
    The space telescope got several repair and upgrade missions. Since the R+D cost of developing the telescope was already spent, it's hard to believe the incremental cost of building and launching another one would have cost more than a shuttle mission.
    - walrus01 6y ago
      LEO is a very, very different thing in terms of exo-atmospheric delta v budget than achieving a circular Geostationary distance orbit with a manned craft.
      - Cthulhu_ 6y ago
        Which is why I really hope the new space telescope will work, since they can't realistically go out there to fix it.

gruez 6y ago

>Graveyard orbits comprise paths at least 300 kilometers above the geosynchronous region, giving the zombie spacecraft room to have their orbits incrementally ground down by the gravity of the sun and moon. Why is the graveyard orbit higher than the orbit for operating satellites? Doesn't that mean when the orbit eventually decays, that the satellite will eventually fall back into the orbit where all the operating satellites are?

nine_k 6y ago
Likely to let these satellites not interfere with the operational satellites right now, and for many decades? Also, the higher the orbit, the more room it has, and the longer it takes to fall from it onto the planet. Maybe we'll be collecting these satellites after these few decades pass, and use them for something.
walrus01 6y ago
At Geostationary distances, there is so little in the way of atmospheric molecules that orbits will not decay over a geological time scale. Humankind could nuke itself into near oblivion, revert to the stone age and rediscover spaceflight in 20,000 years from now and those satellites would still be up there at just about the same altitude. It's very different in terms of atmospheric drag compared to orbits under 1500km.
savrajsingh 6y ago
I get the impression it’s easier to go for a bigger orbit than deorbit when you’re at GEO.
Rebelgecko 6y ago
There's not much going on above GEO, so there's little risk of hitting someone else if/when you lose control of the sat. Orbital decay is pretty minimal at that level.
m4rtink 6y ago
I guess to prevent dead satellites interferring with new ones comming to GEO from below ? Not sure if that's right though as many GEO insertion orbits often have apogeum much higher than the final GEO altitude.

erwinh 6y ago

Lots of material up there, would be interesting to prospect what more tech could be appropriated there for new use-cases. At https://space-search.io https://space-search.io by applying the orbit duration filter lower than 1 (i.e. above geostationary) you can get a good picture of all the satellites currently in that kind of graveyard orbit.

raxxorrax 6y ago

I don't quite understand why they don't decrease their orbit to burn up in the atmosphere. It would certainly be the Kerbal way. Are the satelites too large to burn up?

Monroe13 6y ago
According to some Wikipedia research “De-orbiting a geostationary satellite requires a delta-v of about 1,500 metres per second (4,900 ft/s), whereas re-orbiting it to a graveyard orbit only requires about 11 metres per second (36 ft/s).” https://en.m.wikipedia.org/wiki/Graveyard_orbit https://en.m.wikipedia.org/wiki/Graveyard_orbit
- raxxorrax 6y ago
  Huh, wouldn't have guessed it to be that much, but it makes sense. De-orbiting gets cheaper the higher your orbit is and a geo stationary orbit is high, but not that high.
gameswithgo 6y ago
requires a huge amount of fuel for a geo-stat-sat to get back down.
xenophonf 6y ago
The Kerbal way is to remember that to lower your orbit, you have to slow down, and to slow down requires propellant. You're moving really, really fast in a geosync orbit, so slowing down to lithobrake your satellite would require a _lot_ of propellant. Conversely, to raise your orbit, you have to speed up. And since you're only going up a little bit, you only need a little bit of propellant.
walrus01 6y ago
While theoretically possible, it is a lot easier to put a "spare" 1500-2000m/s of delta v and fuel tankage on a Kerbal spacecraft than in real life. Unless we invent a magical ion thruster with a specific impulse of 30000 nobody is going to put enough fuel on a Geostationary telecom satellite to lower its perigee below 100km at EOL. That same fuel is better used for station keeping and to extend its service life.

saul_goodman 6y ago

I'll just leave this here: http://orbitofshame.org http://orbitofshame.org

dekhn 6y ago

A neighbor of mine worked on the refuelling mission described here. Basically he uses a library of CAD designs to assemble standardized components for satellites. The more I learn about satellite operations the more impressed I get. My favorite was a zombie satellite that woke up after 25+ years and started transmitting again. Apparently, the solar panels had broken in such a way that they transmitted power through the battery (even though the battery could no longer hold a charge), so periodically the satellite would be in illumination and transmit (but it had a very weird pattern because the satellite was spinning out of control). It still blows me away that most satellites, if they have a glitch like losing contact with the ground, will go into "Safe" mode- solar panels fully deployed, directly facing the sun, so it's likely there's enough power to recontact. I have enough trouble implementing a PID-driven motor on my arduino that it impressed me what people can do in space.