Bi-Directional Plasma Thrusters for Space Debris Removal
nature.com
nature.com
Or is it more of a thing that it only becomes more of a noticeable problem for us as humans when we are affected. Meaning that the only reason we have a problem with it now as opposed to some previous timespan is that we are sending more and more objects/satellites/etc into orbit and they are being damaged/destroyed/affected, so we therefore write about it and try and come up with ways to stop it?
Debris in high orbits isn't a big issue; there's too much space. Debris in low orbits falls out of the sky on a timescale of ~decades, thanks to aerobraking. So it should be constant, given a constant inflow of debris...
However, that is only true so long as collisions remain rare. Once there's too much debris, Kessler syndrome will cause it to 'breed' and close the orbitals for decades.
The above also doesn't account for super-popular high orbits, i.e. geosynchronous. A sufficient amount of debris in that orbit could close off that one for millennia (or until cleaned), but at least there are alternatives.
Also Geo orbit (while popular) is only useful if you get a fairly large degree of it all to yourself. My current understanding (correct me if I'm wrong) is that most satellites operate at fairly large distances from each other in Geo about 0.5 degrees apart is normal. Mostly because the antennas sending signals from have a wide beam at the point they hit the satellite and affect adjacent satellites. So they have to distance the Adjacent satellites far enough apart so as to be effective in communications. This isn't a problem for different frequencies, so you might stack a K and C band satellite on top of each other. But most of the Geo beasts have full capacity for the spectrum they are legally allowed to use.
Also, I'm speaking strictly about COMM satellites. I haven't done any practical application on anything else.
The linked bi-directional plasma solution seems really elegant to me. And is feasible even for objects several meters in size. With fewer possible mishaps than say laser ablation.
More detail here:
The quest To Conquer Earth's Space Junk Problem
Of course, some of the most difficult to track debris was put up there in the name of science- the Telford needles, pieces of tether, and shreds of solar sails. If the big net experiment from a couple of weeks ago had gone awry, we'd have another difficult to track fabric-like bit of junk shredding itself into smaller yet still dangerous pieces up there.
https://en.wikipedia.org/wiki/List_of_space_debris_producing...
The final stage boosts the payload into its orbit then separates. Of necessity the final stage tends to be in a very similar orbit to the final payload, except weighing much more. For example, most sightings of the Sputnik spacecraft were actually sightings of the much brighter upper stage tagging along in orbit behind it. Ah but the stage is not necessarily done doing stuff yet, just not stuff it was intentionally designed to do. The stage will often have leftover propellant in it, and it was common to simply abandon the stage in place (on orbit) after its work was done. As a consequences, a lot of upper stages blew up on orbit after delivering payloads, creating yet another shower of debris into Earth orbit.
And finally you have the payload itself, which was very commonly simply abandoned in place once it became derelict.
Multiply all of that by the low operational lifespan of early satellites coupled with a high replacement cadence and you have a reason why Earth orbit got crudded up with debris in a short window of time.
Today we are considerably more sensible about the problems of space debris so our launches are much cleaner. Instead of every launch creating a new mess in orbit every launch generally just inserts 1 or 2 pieces of large, easily trackable components (the payload and the upper stage, if it wasn't deorbited). For LEO launches the upper stage is typically deorbited immediately, for GTO launches the upper stage typically takes a handful of years to orbitally decay and re-enter.
For this reason orbital debris has typically been on a flat or decreasing track over time during any given year. However, there are a few notable events in the past which have generated exceptional amounts of debris. One example is Project West Ford, which put thousands of tiny needles into orbit, which should have re-entered promptly except that some of the needles clumped up, leading them to have long-term stable orbits (which will last hundreds of years most likely), polluting some significant chunks of Earth orbit. Then you have the Iridium/Kosmos-2251 collision and the Chinese ASAT test, both of which injected huge quantities of debris into orbit.
In general, all of these things can be cleaned up given application of modest resources, and the fact that we are no longer polluting Earth orbit with debris as rapidly as we once were means that we should be able to sustain far higher levels of space activity with far lower risks due to orbital debris than today.
A point they've dropped from my proposal is that used on a spinning target you can de-spin it. (Even if it's spinning along more than one axis in fact, with intermittent thrust.) This is especially useful to capture, move, and then utilize asteriods, say. Or as a way to stabilize the target (such as an asteroid), so that both engines can be joined to the target to move it. See "jacknife" below.
Very useful for cleaning debris from orbit.
A few years ago, I realized that what you want is a "jackknife" implementation with a hinge between the two engines that allows you to use both thrusters to move to and from the objects you want to move. Since no-one had picked up the original idea (except as modified to use gravity vs one engine), I made no attempt to publicize that refinement to the idea.
soure: I can't even do basic math, but maybe someone smart will think this is an interesting idea
Side not, you would do this to the 'front' of the satellite as it orbits - the bit facing in the direction of travel. This would slow it down and make it fall into progressively lower orbits until atmospheric braking took over.
It's a bit of flatlander nonsense that should not be brought off the surface. I was shocked as hell when I found out astronauts vent trash and waste.
"Come, let us reason together."
There are not a lot of atoms in space, by definition, compared to terrestrial conditions. (Okay, technically all atoms are in space. You know what I mean. ;-P ) So, if you have some atoms together in space already it's just stupid to disperse them into small bundles and then lose track of their orbit. (You can't throw things away in space, you can only lose track of them. They'll be back.)
It takes a lot of energy to get a bunch of atoms to orbit from the surface. It's wasteful to discard "waste"! (Say it with me, "No waste in space!") Literally, in space, matter is only "waste" because you let go of it and stopped paying attention to it. It's still useful, just not to you right now. Even if you're sure you'll never have a use for it, it's criminally irresponsible to "throw away" matter in space. It's like firing a gun into the air: that bullet is coming down somewhere... At the very least bundle it up and tag it with a radar reflector or something.
In conclusion, space is big and empty and curved, atoms are rare, important, useful, and expensive to bring with you. Keep them nearby and on stable orbits. That way you don't have to waste energy collecting them again and they aren't rattling around forming a collision lottery in LEO.
No waste in space.
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Now then, as a bit of a tangent, are you familiar with the "spittlebug", Cercopoidea? Their nymphs form nests of bubbles that look like little blobs of spittle. I say this is the correct design for space vehicles and stations. Spittlebug nest. Not metal can. Cheap, simple, ridiculously easy construction methods, durable, self-repairing, reusable, flexible, etc... I'm sure we could make materials that permitted different kinds of bubble, for e.g. storage, blocking radiation, absorbing collision energy, etc...
So, build your space stations out of bubbles. If you do it right you can collect debris for free. (Hint: you have to intersperse threads with your bubbles and have the right kinds of glue and stick'um. It's all down to materials science at this point, the spittlebug design doesn't really have any other constraints. You could make a space vehicle that "landed" by simply crashing. Density of the atmosphere and the vehicle would determine velocity at touch down. Or, you just make the bubble nest really big. Like 10K diameter. Then when you "crash" your core ship (which actually might be a metal can) settles to the ground through ~5k of bubblewrap.