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I'm no rocket scientist, but could there be a service which knocks satellites out of orbit for people? I wonder how cost effective such a service could get. Cou

I'm no rocket scientist, but could there be a service which knocks satellites out of orbit for people? I wonder how cost effective such a service could get. Could one mission knock 10 satellites out of orbit?

tejtm 4y ago
Woz seems to think so. https://www.cnn.com/2022/03/01/tech/space-junk-steve-wozniak-privateer-scn/index.html https://www.cnn.com/2022/03/01/tech/space-junk-steve-wozniak...
- MichaelCollins 4y ago
  Given Woz's post-Apple track record, that's not a good sign..
  - genewitch 4y ago
    Doing better than Jobs!
xani_ 4y ago
It would be most likely far more expensive than just adding few kg to your payload to allow for faster deorbit.
simonh 4y ago
Designing the satellites to self de-orbit would be massively more efficient, but this technology is being developed to de-orbit older sats and other debris without that capability. It could also be useful to remove satellites that fail or who's de-orbit system fails. There was a recent test of a grapple system that harpoons a target sat, but it's early days in the development of such systems for arbitrary sats, rather than recovery missions designed for a particular target sat.
dotnet00 4y ago
Astroscale is trying to push a standardized docking adapter for that purpose and Northrop Grumman has a vehicle that was able to dock to the engine of another satellite to serve as a life extension vehicle, so assuming that can be easily adapted to other satellites, they too can provide a deorbiting service. Clearing out several satellites with one vehicle is not practical though, would need too much fuel. At best one might launch several such vehicles on one launch, or if orbital fuel depots really take off soon, it may be possible to have depots in convenient locations such that deorbiting vehicles can always make a relatively cheap visit to a depot to refuel and wait for another deorbiting target. In such a setup the deorbiter would just lower one end of the orbit to speed up decay rather than dragging it all the way down to Earth.
loeg 4y ago
It would cost more than reserving some propellant.
apendleton 4y ago
With a vehicle, probably not. Moving form one satellite's orbit to another is extremely fuel-intensive (you'd typically need ~thousands of km/h of velocity change to do it), so it's not really practical to have a single vehicle up there moving from satellite to satellite. But maybe there'd be some other way to do it? There have been proposals for de-orbiting little pieces of debris from the ground with lasers, and I suppose it's possible that those approaches would scale to bigger objects (or maybe you could do it with lasers from other satellites whose orbits were fixed, or something).
- MichaelCollins 4y ago
  In the far future, perhaps orbit-cleaners could eat dead satellites and space debris, atomizing the debris and turning it into reaction mass.
- dmckeon 4y ago
  A set of satellites that could do laser ablation of debris or EOL sats would be great, but would need safeguards to not become a weapon of economics or war. Avoiding splash-over or collateral damage to other sats in or near the line-of-sight would be an issue, especially if any of those other sats might have capabilities that their nation/owner might want to keep secret. Perhaps an arrangement of vetos over particular ablation shots would suffice. Countries wanting to hide their interests in some sats could veto N times as many shots as needed, making uncovering which sats are special more difficult. In any case, laser ablation would need much less delta-V than the usual imagery of plucky space-cowboys chasing errant sats with a net, or some such. Who knew that _Planetes_ would have such a strong effect on our collective imagination.
benslavin 4y ago
I'm aware of Astroscale (https://astroscale.com/ https://astroscale.com/). They're a Japanese company with a presence in the US and UK that's commercializing this sort of service. I'm not sure if they have plans for multi-satellite de-orbit services, but they do have single-satellite plans. Among other things, they're promoting a standardized docking adapter (https://astroscale.com/docking-plate/ https://astroscale.com/docking-plate/) to give satellite operators a path to either life extension (refueling and/or orbit raising) or de-orbit.
bryanlarsen 4y ago
Going from travelling at Mach 25 in one direction to travelling at Mach 25 in a different direction takes an amount of energy comparable to going from 0 to Mach 25. Being outside of atmosphere helps a lot, and being able to use the less powerful but more efficient electric ion propulsion engines helps a lot, but 10 satellites per mission is usually not feasible. 3 per mission is the number I've heard. Some companies approaching this problem are hoping to utilize refueling depots. It adds another expensive rendezvous but it does help.

tejtm 4y ago

Woz seems to think so. https://www.cnn.com/2022/03/01/tech/space-junk-steve-wozniak-privateer-scn/index.html https://www.cnn.com/2022/03/01/tech/space-junk-steve-wozniak...

MichaelCollins 4y ago
Given Woz's post-Apple track record, that's not a good sign..
- genewitch 4y ago
  Doing better than Jobs!

xani_ 4y ago

It would be most likely far more expensive than just adding few kg to your payload to allow for faster deorbit.

simonh 4y ago

Designing the satellites to self de-orbit would be massively more efficient, but this technology is being developed to de-orbit older sats and other debris without that capability. It could also be useful to remove satellites that fail or who's de-orbit system fails. There was a recent test of a grapple system that harpoons a target sat, but it's early days in the development of such systems for arbitrary sats, rather than recovery missions designed for a particular target sat.

dotnet00 4y ago

Astroscale is trying to push a standardized docking adapter for that purpose and Northrop Grumman has a vehicle that was able to dock to the engine of another satellite to serve as a life extension vehicle, so assuming that can be easily adapted to other satellites, they too can provide a deorbiting service. Clearing out several satellites with one vehicle is not practical though, would need too much fuel. At best one might launch several such vehicles on one launch, or if orbital fuel depots really take off soon, it may be possible to have depots in convenient locations such that deorbiting vehicles can always make a relatively cheap visit to a depot to refuel and wait for another deorbiting target. In such a setup the deorbiter would just lower one end of the orbit to speed up decay rather than dragging it all the way down to Earth.

loeg 4y ago

It would cost more than reserving some propellant.

apendleton 4y ago

With a vehicle, probably not. Moving form one satellite's orbit to another is extremely fuel-intensive (you'd typically need ~thousands of km/h of velocity change to do it), so it's not really practical to have a single vehicle up there moving from satellite to satellite. But maybe there'd be some other way to do it? There have been proposals for de-orbiting little pieces of debris from the ground with lasers, and I suppose it's possible that those approaches would scale to bigger objects (or maybe you could do it with lasers from other satellites whose orbits were fixed, or something).

MichaelCollins 4y ago
In the far future, perhaps orbit-cleaners could eat dead satellites and space debris, atomizing the debris and turning it into reaction mass.
dmckeon 4y ago
A set of satellites that could do laser ablation of debris or EOL sats would be great, but would need safeguards to not become a weapon of economics or war. Avoiding splash-over or collateral damage to other sats in or near the line-of-sight would be an issue, especially if any of those other sats might have capabilities that their nation/owner might want to keep secret. Perhaps an arrangement of vetos over particular ablation shots would suffice. Countries wanting to hide their interests in some sats could veto N times as many shots as needed, making uncovering which sats are special more difficult. In any case, laser ablation would need much less delta-V than the usual imagery of plucky space-cowboys chasing errant sats with a net, or some such. Who knew that _Planetes_ would have such a strong effect on our collective imagination.

benslavin 4y ago

I'm aware of Astroscale (https://astroscale.com/ https://astroscale.com/). They're a Japanese company with a presence in the US and UK that's commercializing this sort of service. I'm not sure if they have plans for multi-satellite de-orbit services, but they do have single-satellite plans. Among other things, they're promoting a standardized docking adapter (https://astroscale.com/docking-plate/ https://astroscale.com/docking-plate/) to give satellite operators a path to either life extension (refueling and/or orbit raising) or de-orbit.

bryanlarsen 4y ago

Going from travelling at Mach 25 in one direction to travelling at Mach 25 in a different direction takes an amount of energy comparable to going from 0 to Mach 25. Being outside of atmosphere helps a lot, and being able to use the less powerful but more efficient electric ion propulsion engines helps a lot, but 10 satellites per mission is usually not feasible. 3 per mission is the number I've heard. Some companies approaching this problem are hoping to utilize refueling depots. It adds another expensive rendezvous but it does help.