Using gas bombs to deorbit space debris?

[Mitchz95]

I apologize if this is a dumb question.

I was reading about the Indian anti-satellite missile incident from March, and it occurred to me that if space debris' orbits naturally decay over time, it might be possible to speed up the decay by putting additional stuff in their way to slow them down. Anything solid is going to shatter it, of course, and there's way too much debris to account for all the stuff in orbit, so you'd need something fairly gentle and indiscriminate. Such as gasses.

Here's what I mean: instead of a kinetic/explosive missile, you launch a bunch of gas canisters on a suborbital trajectory, and detonate them in the path of the debris you're trying to deorbit. The debris flies through the gas and slows down ever so slightly, maybe enough to make a difference over time.

Would this be at all practical? Flying through a thin cloud of gas wouldn't fragment a dead satellite, would it?

[AngrybobH]

If you detonated a gas canister wouldn't you be adding more debris? Of course, if the debris was suborbital, it wouldn't be that much of a problem but, that debris could be struck by what you are trying to deorbit. I see potential problems. As far as an object flying through the gas, it could be utterly obliterated if the gas was sufficiently dense or the object was sufficiently flimsy. Okay, maybe that's an edge case. I do see a potential problem with delivering enough gas at the precise time to make any real difference at all. The question is would it at least be worth the effort and cost to launch a 'gas bomb'? Someone smarter than me could probably answer that.

I like the laser method better. Far less explody but not without its' own issues.

[Cunjo Carl]

That's an interesting idea! We could even avoid the canisters altogether by just bringing up a liquid that could evaporate like like liquid nitrogen (or perhaps even water). For maximum effectiveness, we would want to bring the gas up into a retrograde orbit, so each atom will hit the satellites/debris as hard as possible. Even still, given the scale of space it would still take a great number of orbits through the gas to meaningfully slow a satellite.

But here's the tricky part, anywhere near the Earth our gas atoms will drag on the tenuous atmosphere and deorbit themselves much faster than a satellite would. Meanwhile if the atoms were farther away from the Earth, they'd get swept away by the solar wind! I don't think there's any happy medium for our gas atoms to orbit stably. Perhaps this is a good thing, because if gas could orbit stably, each time a rocket burns in orbit it could smear quite the mess across the sky!

The alternative would be to try to deorbit the satellite it all in one shot with tons of gas particles. A great source of directed gas particles would be a normal rocket engine! It's funny to think about the physics of deorbiting a satellite by pointing a rocket engine at it. The present ideas in progress are instead a space harpoon, and a space net. If I've understood it correctly, the idea behind the net is to attach a big high drag surface onto the satellite so it naturally drags harder against the atmosphere. They've actually even tested it in orbit!

 

[kerbiloid]

10 hours ago, Cunjo Carl said:

But here's the tricky part, anywhere near the Earth our gas atoms will drag on the tenuous atmosphere and deorbit themselves much faster than a satellite would.

An artifical or captured LEO comet.
A piece of sublimating material with a command module on front side.
RCS thrusters keep the comet oriented always prograde.

The rear side sublimates, the gas flow produces both low thrust, holding the comet in orbit, and  gas cloud deorbiting the scattered debris.
The RCS thrusters also redirect the sublimated gas.
The front side is covered with reflective thin film (or painted so).

With additional admixtures can be used as a fumigator against space moths.

Upd.
The comet orbits in retrograde direction, so the debris hit the gas cloud at 16 km/s, partially evaporate, and the drag force is added to the thrust produced by the sublimating debris material.

Edited June 19, 2019 by kerbiloid

[Brotoro]

Orbit a payload that deploys a gigantic plastic bag that fills with chemicals to create a low-density expanding foam. Small objects will embed themselves in the foam. A really fast object might blast through, but it would get slowed down. And any bits of foam blasted out would have such a low ballistic coefficient that they would decay quickly. Deorbit the bag using rocket motors on the deployment stage once it has swept up enough stuff (or let natural decay deorbit it). The motors can also be used to dodge any satellites you don't want to hit, or which might be too big for the bag to handle.

So... like the gas cloud idea, but more substantial and longer lasting.

Edited June 19, 2019 by Brotoro

[Snark]

Gas itself wouldn't work. It would disperse too quickly to be of any use.

6 hours ago, Brotoro said:

Orbit a payload that deploys a gigantic plastic bag that fills with chemicals to create a low-density expanding foam. Small objects will embed themselves in the foam. A really fast object might blast through, but it would get slowed down. And any bits of foam blasted out would have such a low ballistic coefficient that they would decay quickly. Deorbit the bag using rocket motors on the deployment stage once it has swept up enough stuff (or let natural decay deorbit it). The motors can also be used to dodge any satellites you don't want to hit, or which might be too big for the bag to handle.

So... like the gas cloud idea, but more substantial and longer lasting.

This is not unlike an idea I've heard proposed. The suggestion I heard, IIRC, was to use big slabs of aerogel.

No idea how practical it would be.

[Cunjo Carl]

7 hours ago, kerbiloid said:

An artifical or captured LEO comet.
A piece of sublimating material with a command module on front side.
RCS thrusters keep the comet oriented always prograde.

The rear side sublimates, the gas flow produces both low thrust, holding the comet in orbit, and  gas cloud deorbiting the scattered debris.
The RCS thrusters also redirect the sublimated gas.
The front side is covered with reflective thin film (or painted so).

With additional admixtures can be used as a fumigator against space moths.

Upd.
The comet orbits in retrograde direction, so the debris hit the gas cloud at 16 km/s, partially evaporate, and the drag force is added to the thrust produced by the sublimating debris material.

+1. Poetic.