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As a random thought experiment, would a spacex starship with some sort of unfolding kilometre-scale "net" (made of aerogel or whatever) be able to effectively s

As a random thought experiment, would a spacex starship with some sort of unfolding kilometre-scale "net" (made of aerogel or whatever) be able to effectively sweep common orbital planes for the microscopic bits of crap floating around? Then furl the net all back up in the cargo bay, land and recycle/dispose of the debris? I am guessing - given that starship is planned to be able to go to mars - that there is enough fuel and power available that it'd be fairly trivial to just scoop up defunct satellites in the huge cargo hold and deorbit them safely for refurbishment/disposal on the ground. (After all they've shown they can rendevous with ISS etc so I am guessing this is largely the same approach to rendevous with a dead satellite) Guessing you could comfortably hold quite a few satellites inside a starship meaning one launch could collect a whole range of dead satellites?

sparker72678 5y ago
A few problems holding a solution like that back right now: 1) It takes a ton of fuel to change your orbit once you're in space, and space is _really_ big (even just the orbital ranges we're talking about). It's just not currently feasible for a ship like that to capture debris and then use _more_ fuel to bring it back down. 2) Relative velocities of some debris are so large (and they are so spread out) that it's not yet feasible to capture it and bring it back with any current approach. Dead satellites are mostly dangerous for the scattered debris they _might_ become if something hits them/they bread up. So while bringing them back is important, it's not as immediate a danger as things that have already broken up. Basically, we don't have any approach that would make a major difference, even if money was no object (which it is).
amelius 5y ago
It's probably easier to remove all pastic junk from the great pacific garbage patch, where stuff doesn't move around at relativistic speeds.
modeless 5y ago
It's not even close to feasible IMO. These pieces of debris are traveling many times faster than bullets and they have significant mass. They would rip aerogel to shreds. You would need square kilometers of bulletproof armor. Imagine a project to catch all the fish in the ocean except the ocean is a million times bigger, the fish are going as fast as bullets, and every fishing trawler costs a billion dollars. And you can't sell the fish to fund it. Retrieving whole defunct satellites is possible but only one or two at a time because of the huge amount of fuel needed to match orbits with each one. And once you've grabbed one it takes even more fuel to de-orbit it (which you'll notice didn't happen here). Don't forget that every maneuver you make as a spacecraft has to use extra fuel just to haul all the fuel for every future maneuver you'll ever do, and that compounds for every lifetime maneuver. It's worthwhile to dispose of old satellites so they don't collide and produce debris clouds that are basically impossible to clean forever, but it's not funded.
senectus1 5y ago
anything in orbit is falling, not floating. Most of them falling at terrific rates oh and in lots of different directions. that net would have to be incredibly strong, also be able to stop spalling when objects in the net collide...

sparker72678 5y ago

A few problems holding a solution like that back right now: 1) It takes a ton of fuel to change your orbit once you're in space, and space is _really_ big (even just the orbital ranges we're talking about). It's just not currently feasible for a ship like that to capture debris and then use _more_ fuel to bring it back down. 2) Relative velocities of some debris are so large (and they are so spread out) that it's not yet feasible to capture it and bring it back with any current approach. Dead satellites are mostly dangerous for the scattered debris they _might_ become if something hits them/they bread up. So while bringing them back is important, it's not as immediate a danger as things that have already broken up. Basically, we don't have any approach that would make a major difference, even if money was no object (which it is).

amelius 5y ago

It's probably easier to remove all pastic junk from the great pacific garbage patch, where stuff doesn't move around at relativistic speeds.

modeless 5y ago

It's not even close to feasible IMO. These pieces of debris are traveling many times faster than bullets and they have significant mass. They would rip aerogel to shreds. You would need square kilometers of bulletproof armor. Imagine a project to catch all the fish in the ocean except the ocean is a million times bigger, the fish are going as fast as bullets, and every fishing trawler costs a billion dollars. And you can't sell the fish to fund it. Retrieving whole defunct satellites is possible but only one or two at a time because of the huge amount of fuel needed to match orbits with each one. And once you've grabbed one it takes even more fuel to de-orbit it (which you'll notice didn't happen here). Don't forget that every maneuver you make as a spacecraft has to use extra fuel just to haul all the fuel for every future maneuver you'll ever do, and that compounds for every lifetime maneuver. It's worthwhile to dispose of old satellites so they don't collide and produce debris clouds that are basically impossible to clean forever, but it's not funded.

senectus1 5y ago

anything in orbit is falling, not floating. Most of them falling at terrific rates oh and in lots of different directions. that net would have to be incredibly strong, also be able to stop spalling when objects in the net collide...