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> That's why they want to get it up into the graveyard orbit before the eclipse, so if it explodes, it does so in a orbit where the debris are very unlikely to

> That's why they want to get it up into the graveyard orbit before the eclipse, so if it explodes, it does so in a orbit where the debris are very unlikely to disrupt the operation of active satellites. A graveyard orbit sounds like it will be flying around up their indefinitely as high speed shrapnel. Does anyone know why they would choose this instead of destroying it on re-entry?

sidewndr46 7y ago
Getting from Geostationary orbit to re-entry is not easy. It isn't like the ISS where essentially if you blink, the thing burns up in the atmosphere. You need a huge amount of delta-v. My guess is the satellite is in poor enough condition they aren't 100% certain they can get it to start hitting the atmosphere before the imminent explosion occurs.
dralley 7y ago
My guess is that Geosynchronous Orbit at too high an altitude for them to re-enter the atmosphere under their time or fuel constraints. http://acqnotes.com/wp-content/uploads/2014/09/Orbit-Map.png http://acqnotes.com/wp-content/uploads/2014/09/Orbit-Map.png But it's just a guess.
orclev 7y ago
> A graveyard orbit sounds like it will be flying around up their indefinitely as high speed shrapnel. Does anyone know why they would choose this instead of destroying it on re-entry? It sounds like there's confusion about that point. The article says that the plan says that they're going to de-orbit the satellite so it can burn up on reentry, and that it will be in a graveyard orbit, which are contradictory objectives to each other. It sounds like AT&T hasn't responded yet to clarify which of the two they actually meant.
- zentiggr 7y ago
  I think in this case the use of 'de-orbit' only means removing it from its in-service geosynchronous orbit, to the graveyard orbit. De-orbit down around usual LEO altitudes is more drag-effect, you will return to Earth soon enough anyway.
ufmace 7y ago
Geostationary orbit is very high. It would be cost-prohibitive for satellites designed for geostationary service to maintain enough fuel to drop their orbits into the atmosphere. Instead, they move them into a slightly higher graveyard orbit, where hopefully any collision or breakup debris is unlikely to be able to get to an orbit where it could intersect a satellite still in service. I guess there's a hope that someday we'll figure out a way to recover and permanently de-orbit all of them.
- klarstrup 7y ago
  "It would be cost-prohibitive not to litter" If one can't do business without carelessly leveraging finite public resources I would argue that that business is untenable
  - ineedasername 7y ago
    Untenable only in a stable-state eco/technological culture. If, however, the technological culture of which satellites are a part is able to bootstrap itself through behaviors that are only viable in the short term, and burst through to levels of capability that are long-term viable and can rectify the short-term behaviors that came before, then everything can work out alright. I know, I know, the above is close to hopelessly optimistic. It's like when I was younger: I remember thinking, "I'm not going to smoke cigarettes, but if I did it would probably be okay. By the time it would really matter, medicine will have surely found cures." I was an idiot, though I never did smoke.
  - 627467 7y ago
    This is the type of judgmental comment/rationale that we hear around climate change as well... 'if humanity never knew how to do it properly - considering forseen and unforseen circustances - we should never have done it' Public resources are always consumed while public exists. We should thrive to always experiment, learn from it and evolve/do better.
  - fennecfoxen 7y ago
    Do you hold graveyard orbits located 11m/s above GEO to be an inadequate or irresponsible way of preserving the integrity of GEO?
tehbeard 7y ago
https://en.wikipedia.org/wiki/Graveyard_orbit https://en.wikipedia.org/wiki/Graveyard_orbit puts the difference in delta V requirements for a geo-sync orbit at ~1500m/s to de-orbit vs 11m/s to get boost up to graveyard orbit.
- penagwin 7y ago
  Oh... Yeah that explains it for sure.
  - zymhan 7y ago
    Essentially, you need a ton of fuel to take a satellite back down to earth.
- staticautomatic 7y ago
  So it's more expensive to design satellites that can de-orbit?
  - mumblemumble 7y ago
    It depends on where they are. Take a look at the diagram on that Wikipedia page linked above - a geosynchronous orbit is very high; 50 or so times further out than the ISS, for example. And that's about as far out as we ever put satellites, so you've only got to boost it by a little bit to get out of the way of active space traffic.
  - penagwin 7y ago
    From Geostationary Orbit yes, for other orbits it can be the opposite. Satellites in lower positions actually have to maintain their orbit due to orbital decay. Because Geostationary orbit is so far away, there's a lot less decay. For example SpaceX's starlink only has a lifespan of 5 years, and this is because of their low orbit.
- dls2016 7y ago
  What's the physical intuition here? Is it that you want the de-orbit to hit the atmosphere at a shallow angle instead of plunging to earth?
panzagl 7y ago
It would take too much energy to de-orbit quickly, it's probably pretty big and unlikely to be fully destroyed in the atmosphere, and there's not much beyond geo for a shrapnel cloud to run into.
- deleted 7y ago
  [deleted]
snuxoll 7y ago
> A graveyard orbit sounds like it will be flying around up their indefinitely as high speed shrapnel. Does anyone know why they would choose this instead of destroying it on re-entry? Because the ∆v required to re-enter the atmosphere is significantly higher than that required to leave geosynchronous orbit for a higher graveyard orbit. But yes, ultimately it will remain up there as "high speed shrapnel" - which is not an ideal situation, and continuing to treat disposal as we have may put us in a situation where these orbits become so full of high speed garbage that they are unusable. As a species, we need to do more work on cleaning up our space garbage before it's too late. Kurzgesagt actually has a great video on the topic of space debris for anyone interested: https://www.youtube.com/watch?v=yS1ibDImAYU https://www.youtube.com/watch?v=yS1ibDImAYU
- phkahler 7y ago
  Starship should make it feasible to go garbage collecting up there. That doesnt mean anyone will pay for it though.
  - penagwin 7y ago
    Keep in mind to do garbage collecting you are essentially trying to intercept high-speed objects that likely have no telemetry. If your speed and orbit aren't correct, or if there's shrapnel or other debris, you'll destroy your ship. And you can only pickup garbage that's in a similar orbit too.
    - greglindahl 7y ago
      We're talking about the graveyard orbit, which is not far from geosynchronous orbit. In fact there's such an intercept being done soon, the mission extension vehicle (MEV) is going to rendezvous with an old but still controlled satellite in order to extend its useful life. This rendezvous is being done in the graveyard orbit in case something goes wrong. https://en.wikipedia.org/wiki/Mission_Extension_Vehicle https://en.wikipedia.org/wiki/Mission_Extension_Vehicle
  - toyg 7y ago
alex_young 7y ago
For everyone worried about polluting geo distance orbits, consider that geosynchronous is about 35,786 km from the surface, or about 6x the radius of the earth away. Suffice to say this is a very great distance, and the probability of a collision orbit at this distance is so phenomenally unlikely that even if left in place there is nothing to consider of this risk. Moving to a higher and unused orbit means nothing will ever impact it in any human time horizon.
- azinman2 7y ago
  Can that really be true? You’re still having the thing rotate along. I worry about space filling up with satellites with no good ability to retrieve them..
  - mandevil 7y ago
    Space is really, really big. When you hear that the Sun has an Asteroid belt, you imagine that it is like Empire Strikes Back. In actuality, the belt works out to 1 extra atom per m^3 of space, because, well, see above about how big space is. That is basically what we're talking about with satellites here- all of our space junk in graveyard orbits is less dense than that, last I checked (which was 4-5 years ago). Low Earth Orbit is a bigger concern; but much of the concern in that region is spent rocket stages which have enough propellant inside them that they eventually explode and then for several months-years we have lots of debris (and then threat of a Kessler Cascade). The international community has responded to this threat by adding regulations on the proper disposal of spent rocket stages. (Occasionally, similar to this satellite, there are failed stages which do explode, but it should not happen often or on a normal path.)
larkeith 7y ago
Note that because the Earth is tilted, this region of space is pretty much useless - there's very few (if any) useful orbits beyond a geostationary, and any spacecraft heading into interplanetary space is going to be aligned with the plane of the solar system (ecliptic), and won't pass through GEO or graveyard orbits. So while you do get shrapnel, it's spread across a very large region through which nobody travels.
- nucleardog 7y ago
  This graphic on Wikipedia is probably really helpful to visualize some of this: https://en.wikipedia.org/wiki/Kessler_syndrome#/media/File:Debris-GEO1280.jpg https://en.wikipedia.org/wiki/Kessler_syndrome#/media/File:D... While there's a lot of space junk up there, you can see that the graveyard orbit is in fact a fairly tight line around the equator. It should be quite easy to avoid. From the look of it, it's kinda functionally equivalent to putting a fence around an airport. I mean, sure, it theoretically limits your options, but not in any practical way.

sidewndr46 7y ago

Getting from Geostationary orbit to re-entry is not easy. It isn't like the ISS where essentially if you blink, the thing burns up in the atmosphere. You need a huge amount of delta-v. My guess is the satellite is in poor enough condition they aren't 100% certain they can get it to start hitting the atmosphere before the imminent explosion occurs.

dralley 7y ago

My guess is that Geosynchronous Orbit at too high an altitude for them to re-enter the atmosphere under their time or fuel constraints. http://acqnotes.com/wp-content/uploads/2014/09/Orbit-Map.png http://acqnotes.com/wp-content/uploads/2014/09/Orbit-Map.png But it's just a guess.

orclev 7y ago

> A graveyard orbit sounds like it will be flying around up their indefinitely as high speed shrapnel. Does anyone know why they would choose this instead of destroying it on re-entry? It sounds like there's confusion about that point. The article says that the plan says that they're going to de-orbit the satellite so it can burn up on reentry, and that it will be in a graveyard orbit, which are contradictory objectives to each other. It sounds like AT&T hasn't responded yet to clarify which of the two they actually meant.

zentiggr 7y ago
I think in this case the use of 'de-orbit' only means removing it from its in-service geosynchronous orbit, to the graveyard orbit. De-orbit down around usual LEO altitudes is more drag-effect, you will return to Earth soon enough anyway.

ufmace 7y ago

Geostationary orbit is very high. It would be cost-prohibitive for satellites designed for geostationary service to maintain enough fuel to drop their orbits into the atmosphere. Instead, they move them into a slightly higher graveyard orbit, where hopefully any collision or breakup debris is unlikely to be able to get to an orbit where it could intersect a satellite still in service. I guess there's a hope that someday we'll figure out a way to recover and permanently de-orbit all of them.

klarstrup 7y ago
"It would be cost-prohibitive not to litter" If one can't do business without carelessly leveraging finite public resources I would argue that that business is untenable
- ineedasername 7y ago
  Untenable only in a stable-state eco/technological culture. If, however, the technological culture of which satellites are a part is able to bootstrap itself through behaviors that are only viable in the short term, and burst through to levels of capability that are long-term viable and can rectify the short-term behaviors that came before, then everything can work out alright. I know, I know, the above is close to hopelessly optimistic. It's like when I was younger: I remember thinking, "I'm not going to smoke cigarettes, but if I did it would probably be okay. By the time it would really matter, medicine will have surely found cures." I was an idiot, though I never did smoke.
- 627467 7y ago
  This is the type of judgmental comment/rationale that we hear around climate change as well... 'if humanity never knew how to do it properly - considering forseen and unforseen circustances - we should never have done it' Public resources are always consumed while public exists. We should thrive to always experiment, learn from it and evolve/do better.
- fennecfoxen 7y ago
  Do you hold graveyard orbits located 11m/s above GEO to be an inadequate or irresponsible way of preserving the integrity of GEO?

tehbeard 7y ago

https://en.wikipedia.org/wiki/Graveyard_orbit https://en.wikipedia.org/wiki/Graveyard_orbit puts the difference in delta V requirements for a geo-sync orbit at ~1500m/s to de-orbit vs 11m/s to get boost up to graveyard orbit.

penagwin 7y ago
Oh... Yeah that explains it for sure.
- zymhan 7y ago
  Essentially, you need a ton of fuel to take a satellite back down to earth.
staticautomatic 7y ago
So it's more expensive to design satellites that can de-orbit?
- mumblemumble 7y ago
  It depends on where they are. Take a look at the diagram on that Wikipedia page linked above - a geosynchronous orbit is very high; 50 or so times further out than the ISS, for example. And that's about as far out as we ever put satellites, so you've only got to boost it by a little bit to get out of the way of active space traffic.
- penagwin 7y ago
  From Geostationary Orbit yes, for other orbits it can be the opposite. Satellites in lower positions actually have to maintain their orbit due to orbital decay. Because Geostationary orbit is so far away, there's a lot less decay. For example SpaceX's starlink only has a lifespan of 5 years, and this is because of their low orbit.
dls2016 7y ago
What's the physical intuition here? Is it that you want the de-orbit to hit the atmosphere at a shallow angle instead of plunging to earth?

panzagl 7y ago

It would take too much energy to de-orbit quickly, it's probably pretty big and unlikely to be fully destroyed in the atmosphere, and there's not much beyond geo for a shrapnel cloud to run into.

deleted 7y ago
[deleted]

snuxoll 7y ago

> A graveyard orbit sounds like it will be flying around up their indefinitely as high speed shrapnel. Does anyone know why they would choose this instead of destroying it on re-entry? Because the ∆v required to re-enter the atmosphere is significantly higher than that required to leave geosynchronous orbit for a higher graveyard orbit. But yes, ultimately it will remain up there as "high speed shrapnel" - which is not an ideal situation, and continuing to treat disposal as we have may put us in a situation where these orbits become so full of high speed garbage that they are unusable. As a species, we need to do more work on cleaning up our space garbage before it's too late. Kurzgesagt actually has a great video on the topic of space debris for anyone interested: https://www.youtube.com/watch?v=yS1ibDImAYU https://www.youtube.com/watch?v=yS1ibDImAYU

phkahler 7y ago
Starship should make it feasible to go garbage collecting up there. That doesnt mean anyone will pay for it though.
- penagwin 7y ago
  Keep in mind to do garbage collecting you are essentially trying to intercept high-speed objects that likely have no telemetry. If your speed and orbit aren't correct, or if there's shrapnel or other debris, you'll destroy your ship. And you can only pickup garbage that's in a similar orbit too.
  - greglindahl 7y ago
    We're talking about the graveyard orbit, which is not far from geosynchronous orbit. In fact there's such an intercept being done soon, the mission extension vehicle (MEV) is going to rendezvous with an old but still controlled satellite in order to extend its useful life. This rendezvous is being done in the graveyard orbit in case something goes wrong. https://en.wikipedia.org/wiki/Mission_Extension_Vehicle https://en.wikipedia.org/wiki/Mission_Extension_Vehicle
- toyg 7y ago

alex_young 7y ago

For everyone worried about polluting geo distance orbits, consider that geosynchronous is about 35,786 km from the surface, or about 6x the radius of the earth away. Suffice to say this is a very great distance, and the probability of a collision orbit at this distance is so phenomenally unlikely that even if left in place there is nothing to consider of this risk. Moving to a higher and unused orbit means nothing will ever impact it in any human time horizon.

azinman2 7y ago
Can that really be true? You’re still having the thing rotate along. I worry about space filling up with satellites with no good ability to retrieve them..
- mandevil 7y ago
  Space is really, really big. When you hear that the Sun has an Asteroid belt, you imagine that it is like Empire Strikes Back. In actuality, the belt works out to 1 extra atom per m^3 of space, because, well, see above about how big space is. That is basically what we're talking about with satellites here- all of our space junk in graveyard orbits is less dense than that, last I checked (which was 4-5 years ago). Low Earth Orbit is a bigger concern; but much of the concern in that region is spent rocket stages which have enough propellant inside them that they eventually explode and then for several months-years we have lots of debris (and then threat of a Kessler Cascade). The international community has responded to this threat by adding regulations on the proper disposal of spent rocket stages. (Occasionally, similar to this satellite, there are failed stages which do explode, but it should not happen often or on a normal path.)

larkeith 7y ago

Note that because the Earth is tilted, this region of space is pretty much useless - there's very few (if any) useful orbits beyond a geostationary, and any spacecraft heading into interplanetary space is going to be aligned with the plane of the solar system (ecliptic), and won't pass through GEO or graveyard orbits. So while you do get shrapnel, it's spread across a very large region through which nobody travels.

nucleardog 7y ago
This graphic on Wikipedia is probably really helpful to visualize some of this: https://en.wikipedia.org/wiki/Kessler_syndrome#/media/File:Debris-GEO1280.jpg https://en.wikipedia.org/wiki/Kessler_syndrome#/media/File:D... While there's a lot of space junk up there, you can see that the graveyard orbit is in fact a fairly tight line around the equator. It should be quite easy to avoid. From the look of it, it's kinda functionally equivalent to putting a fence around an airport. I mean, sure, it theoretically limits your options, but not in any practical way.