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I've been curious why we don't start pushing de-commissioned satellites / space junk in earth orbit into a moon-like mass orbiting earth? It would take a swarm

I've been curious why we don't start pushing de-commissioned satellites / space junk in earth orbit into a moon-like mass orbiting earth? It would take a swarm of maybe a few hundred powered "satellite movers" maybe a decade. But in time, seems like it could become a fantastic means of dealing with space debris surrounding earth especially space junk that can't easily be ditched to re-enter the earth's atmosphere and burn up.

vosper 6y ago
Perhaps it would just move the problem from the earth to the moon? If we're going to the effort to build "satellite movers" to get unwanted/dead satellites to a moon orbit, then perhaps we would be better of just sending them into the sun, or on a path out into deep space?
- kempbellt 6y ago
  It would be better to glob them together for a space station to repurpose the materials. A lot of time, energy and money is spent getting material into orbit. No sense wasting it, unless it's completely useless. Then de-orbiting in the Earth's atmosphere is the cheapest solution.
- dogma1138 6y ago
  I would say having shit in lunar orbit might be a bigger problem since they will not burn on reentry. Sure it’s not a problem now but by the time we can push junk into a lunar orbit the moon might be quite a bit more populated.
- dave_4_bagels 6y ago
  I thought about that too, but the benefit of an orbiting "globule" of satellite waste is that in time it would have it's own micro-gravity and require less energy to "commit" waste to a mini-moon than pushing out of earth's orbit to the sun? I haven't done the napkin math but maybe I'm sorely mistaken in terms of the physics involved. Could be interesting to lower the cost by pushing into a huge mass and then once it was too large pushing that mass into the sun?
jl6 6y ago
Some possible reasons: * Lots of space junk is very small (e.g. paint flecks and metal chips) and we don’t know exactly where it is (but even objects of this small size can still be hazardous travelling at 5km/s). * When we do know where it is, it’s probably still uneconomic to spend delta-V getting to it and pushing it anywhere. * Potentially unknown payloads on old satellites, or uncertain ownership status. Russia might have opinions on someone else touching its junk. * Proliferation risk of developing technology that can easily interfere with satellites on-demand. If a satellite mover can move junk, it can move live units too. * Actual risk of error causing uncontrolled deorbiting, either with a mis-push, or by bouncing junk off the growing moon-like mass * That moon-like mass could easily become a liability - irregularly shaped with hard-to-model behaviour. Most space junk will burn up on reentry, but a giant agglomeration of metal might survive reentry and land on something it shouldn’t.
- dylan604 6y ago
  * When we do know where it is, it’s probably still uneconomic to spend delta-V getting to it and pushing it anywhere. Do we need to spend delta-V? We can use a friggin' laser, or a giant magnet, or or or. Typically, we'd just need to slow it down so that it just re-enters the atmosphere. * Proliferation risk of developing technology that can easily interfere with satellites on-demand. If a satellite mover can move junk, it can move live units too. Like anything else, actions have consequences. To be able to make something like this, they'd have to be a pretty decent player in the space realm. If all of the other players quit playing with you because you break all of the rules, the game gets lonely.
walrus01 6y ago
> I've been curious why we don't start pushing de-commissioned satellites / space junk in earth orbit into a moon-like mass orbiting earth? if you randomly choose 20 dead satellites by their TLEs, they're all in different inclinations and orbits. plane change manoeuvres are very costly in delta-v. there is no economic incentive or need to build a lot of individual dead-satellite-grabbing ion/hall effect thruster powered satellites that would go up and grab things to shove them into a katamari-damacy like ball of dead satellites.
m4rtink 6y ago
This is being done when spacecraft are about to fail (usually due to propelant running out), they are moved to a graveyard orbit: https://en.m.wikipedia.org/wiki/Graveyard_orbit https://en.m.wikipedia.org/wiki/Graveyard_orbit
- bagels 6y ago
  Just for geostationary objects that are still functional.
  - m4rtink 6y ago
    Also the nuclear reactor cores from Soviet US-A satellites: https://en.wikipedia.org/wiki/US-A https://en.wikipedia.org/wiki/US-A It mostly worked fine & 30 odd discarded cores are orbiting the Earth in a safe graveyard orbit. Just a few fell back.

vosper 6y ago

Perhaps it would just move the problem from the earth to the moon? If we're going to the effort to build "satellite movers" to get unwanted/dead satellites to a moon orbit, then perhaps we would be better of just sending them into the sun, or on a path out into deep space?

kempbellt 6y ago
It would be better to glob them together for a space station to repurpose the materials. A lot of time, energy and money is spent getting material into orbit. No sense wasting it, unless it's completely useless. Then de-orbiting in the Earth's atmosphere is the cheapest solution.
dogma1138 6y ago
I would say having shit in lunar orbit might be a bigger problem since they will not burn on reentry. Sure it’s not a problem now but by the time we can push junk into a lunar orbit the moon might be quite a bit more populated.
dave_4_bagels 6y ago
I thought about that too, but the benefit of an orbiting "globule" of satellite waste is that in time it would have it's own micro-gravity and require less energy to "commit" waste to a mini-moon than pushing out of earth's orbit to the sun? I haven't done the napkin math but maybe I'm sorely mistaken in terms of the physics involved. Could be interesting to lower the cost by pushing into a huge mass and then once it was too large pushing that mass into the sun?

jl6 6y ago

Some possible reasons: * Lots of space junk is very small (e.g. paint flecks and metal chips) and we don’t know exactly where it is (but even objects of this small size can still be hazardous travelling at 5km/s). * When we do know where it is, it’s probably still uneconomic to spend delta-V getting to it and pushing it anywhere. * Potentially unknown payloads on old satellites, or uncertain ownership status. Russia might have opinions on someone else touching its junk. * Proliferation risk of developing technology that can easily interfere with satellites on-demand. If a satellite mover can move junk, it can move live units too. * Actual risk of error causing uncontrolled deorbiting, either with a mis-push, or by bouncing junk off the growing moon-like mass * That moon-like mass could easily become a liability - irregularly shaped with hard-to-model behaviour. Most space junk will burn up on reentry, but a giant agglomeration of metal might survive reentry and land on something it shouldn’t.

dylan604 6y ago
* When we do know where it is, it’s probably still uneconomic to spend delta-V getting to it and pushing it anywhere. Do we need to spend delta-V? We can use a friggin' laser, or a giant magnet, or or or. Typically, we'd just need to slow it down so that it just re-enters the atmosphere. * Proliferation risk of developing technology that can easily interfere with satellites on-demand. If a satellite mover can move junk, it can move live units too. Like anything else, actions have consequences. To be able to make something like this, they'd have to be a pretty decent player in the space realm. If all of the other players quit playing with you because you break all of the rules, the game gets lonely.

walrus01 6y ago

> I've been curious why we don't start pushing de-commissioned satellites / space junk in earth orbit into a moon-like mass orbiting earth? if you randomly choose 20 dead satellites by their TLEs, they're all in different inclinations and orbits. plane change manoeuvres are very costly in delta-v. there is no economic incentive or need to build a lot of individual dead-satellite-grabbing ion/hall effect thruster powered satellites that would go up and grab things to shove them into a katamari-damacy like ball of dead satellites.

m4rtink 6y ago

This is being done when spacecraft are about to fail (usually due to propelant running out), they are moved to a graveyard orbit: https://en.m.wikipedia.org/wiki/Graveyard_orbit https://en.m.wikipedia.org/wiki/Graveyard_orbit

bagels 6y ago
Just for geostationary objects that are still functional.
- m4rtink 6y ago
  Also the nuclear reactor cores from Soviet US-A satellites: https://en.wikipedia.org/wiki/US-A https://en.wikipedia.org/wiki/US-A It mostly worked fine & 30 odd discarded cores are orbiting the Earth in a safe graveyard orbit. Just a few fell back.