How to efficiently deorbit space junk [duplicate]

Question

Setting: Nearish future where corporate space ventures have had maybe a hundred years of launching satellites and missions and tourists into earth's orbit.

Issue: Launching anything is difficult now because you've got to make it through a million bits of space junk. Picture that scene in Wall-E where eve's ship has to smack its way through a bunch of junk in earth's atmosphere.

Partial solution: Contractors are hired to go up into space in their ships and get rid of that trash so that things like communications satellites and manned missions don't get obliterated and rockets can be launched more easily.

Problem with the partial solution: De-orbiting space junk takes fuel. Some of this stuff has a lot of Delta-V. Matching speed, docking, and deorbiting the space junk would take tons of fuel... more than is probably possible or efficient for removing the volume of junk that needs to be removed. Blowing up the junk doesn't work, it just turns one big trash bullet into a thousand tiny trash bullets traveling at the same speed as before in a less predictable orbit.

My idea: A ship that interfaces with and steers a giant tunnel of an electromagnet onto space junk, then acts as a huge railgun and fires the junk either to escape velocity or back into earth's atmosphere. Is this feasible? Is there an easier solution? If you like this solution, how do you think something like this would work? I like it because the trash-moving method can be accomplished electronically and charged with solar cells... but I feel like there must be a less cumbersome solution that doesn't require a massive orbital railgun (very expensive for the space trash company)

No magic, no infinite fuel sources, and as cheap as possible for the most profit per bit of junk deorbited.

Edit: I'm particularly interested in keeping my crew and their ship in space for as long as possible to avoid costly launch/reentry. Economy is a huge factor here - it needs to be cheap. Picture a company looking to make the most off of a low wage crew.

Answer 1

When the U.N. put a bounty on space junk, it was the birth of a new breed of men... the space cowboys. With their ships safely parked at previously cleared safe orbital heights, these fearless desperadoes would rocket through low earth orbit in jet-pack assisted space suits hunting for high-mass/high-profit space junk.

Upon spotting a likely target, the space cowboy would deploy his lasso (which was actually more like a polymer steel fishing net) and catch the stray "buck" as it passed by. Now high value bucks can out-mass the lone cowboy pretty dramatically, so a successful capture usually led to an lengthy and wild ride, with the cowboy being dragged across the sky, holding onto his lasso and praying for dear life.

Usually those prayers got answered by another cowboy towing buck passing by within range yet travelling on a different vector. With lightning reflexes, the cowboys would fling ropes to each other and tie the two captured bucks together. Then they would watch as the bucks' opposing courses stole velocity and momentum from one or both. Soon enough, both bucks would be crashing down into the atmosphere and the cowboys would head home to their ships, having earned another bounty.

Those were the good old days, when the sky was so full of flotsam, that a fearless man could always find a fair wage. Before the silk gloved hand of civilization reached up into the orbital heights and forced real men to seek their livelihood ever outward, farther and farther, out among the stars.

Answer 2

If I understand correctly, your Kessler remediator would be a long linear electric motor, which would be positioned in such a way as to share the same orbit with a derelict. When the derelict enters the cylinder, the latter is energized and the derelict is either accelerated or decelerated.

The two problems I see are the possibility of a collision with the cylinder (which will be asymmetrical and possibly tumbling, and the fact that even if you don't match orbits with the derelict, you need to keep station on an orbit for which you don't have the "vee". Possibly you can do this through a dynamo effect, pumping solar-panel charge along a wire extending down through Earth's magnetic field.

Answer 3

One problem: satellites are mostly aluminum and not magnetic. The main factor when launching materials into space is weight, not strength, so there isn't much steel involved.

Near-future space materials will likely be even less magnetic: carbon fiber, honeycomb Kevlar, nano-tubes, graphene, aerogels and microlattice. Circuits might be printed on glass and use photonic processors.

After a quick search around the web, it looks like ESA and the other space agencies are looking at nets and tethers that drag the debris down to the atmosphere, one-by-one.

I like your Space Roomba device better, like an orbital vacuum cleaner. Maybe it could have a variety of "weapons" to attack clutter: lasers, sticky thread (like a chameleon tongue), one company is testing a static electricity Swiffer™. Maybe it could shoot plastic pellets to knock debris down to burn in the atmosphere (not sure how pellets wouldn't make more space debris).

The problem with flinging debris away from the Earth is it would need escape velocity or you aren't doing anyone any favors. Easier to knock debris down the gravity well.

Answer 4

Rather than a lasso or a net, maybe they could lower large bit of a very sticky material into this area. Like a large bit of blue tack and the space debris would hit this tack and get stuck to it.

This could then be retrieved at the higher orbit and then safely ejected towards earth as a lump into the drop zone on earth for space debris.

This either burns up on entry or could be safely sent back home using the space debris to construct a re-entry vechicle.

Answer 5

The problem is non-existent. This big ball called Earth has a thing called gravity. Everything that is in its orbit will fall to the surface.
You write about hundred's of years of launching things into space. Right now we are designing things to leave the least amount of debris. The one that is already in the orbit will fall to Earth in the century bracket.

The main problems with debris are:

1. their fall orbit is unpredictable
2. they hit things in orbit while being in space

The second problem is also your solution. You just send a small satellite with large unfolding sails that catch debris and after a while the satellite sets its course to a place on Earth in as "burning" orbit as it can, while steering away from launch paths.