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Space Debris Removal

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at the current strongest electro-magnets we have, what would be the orbits and distances needed to

manuver a cleanup orbiter


what i mean is, if we could have 3 different altitudes and multiple sattelites pwered by solar power


with an on boeard electromagnet on the debris collecter


what is the minimal amount of sattelites needed to be able to manuipulate a satelite in orbit,


and change its vector in a predictable fashon


would it be worth trying to design a system

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magnets would only work up to a point though. the majority of satellite material (which without further research i'm guessing makes up the vast majority of space junk) is aluminium, titanium and composite materials (graphite fibres and the like). steel is the only magnetic metal employed and its use is mainly limited to engines.


most of the more feasible clean up methods that have been proposed employ some means of slowing down the object that we want to clean up, meaning that it re-enters in a more or less controlled way. the downside is that this works better for the larger pieces. the countless smaller pieces are very hard to clean up and probably present the biggest risk.

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i was pondering that also


i think it would all have to do with timing


and the orbits of the objects would change as you repel or attract the orbiter also

then again,


you could use the iss as a tare point


reset orbits as the station passes by or something


i don't know if our magnets are powerful enough to do such a thing though

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  • 2 weeks later...

ok, so how about a teathered system where it connects to the iss


and has a teather kilometers long


then you have something similat to an inflatable module

that is the electromagnet


so as the iss orbits


you can release the teather in a controlled fashon to intersect the orbit of the


cleanup module


then yolu retract the teather until neccisary to intersect the orbit again


with multiple large electromagnets, you could control even if in small increments


the orbit of the cleanup module

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To see the problem with using a magnet to clean up orbiting space junk, you’ve got to look at how a magnet works.


The precise math of them is complicated, but a sketchy image isn’t, and can help you understand the math.


A magnet (permanent or elecro) generates a magnetic field. Feromagnetic materials, such as the steel (but not aluminum) in a piece of space debris close enough to this field will align the atoms in it to essentially become an extension of the magnet.


The problem here is, that unlike electrostatic attraction, which follows a simple distance squared law (

[math]|\boldsymbol{F}|=k_e \frac{|q_1q_2|}{r^2}[/math]

), magnetic field strength follows, approximately and complicatedly, a distance to the fourth law (

[math]F_r(\mathbf{r}, \alpha, \beta) = - \frac{3 \mu_0}{4 \pi}\frac{m_2 m_1}{r^4}\left[2\cos(\phi - \alpha)\cos(\phi - \beta)- \sin(\phi - \alpha)\sin(\phi - \beta)\right][/math]


Ignoring all but the essentials of this, we can see that a magnet that attracts a magnetic material with a force of, say, 1 N at 1 m will attract it with only [imath]\frac{1}{16} \,\mbox{N}[/imath] at 2 m, [imath]\frac{1}{10000} \,\mbox{N}[/imath] at 10 m, etc.


A powerful electromagnet like the kind that lifts scrap around a scrapyard has a force on a big piece of steel of perhaps 100000 N, at a distance of perhaps 0.05 m, so at 1 m, the force would be down to about .625 N, about the weight of a golf ball. At 10 M, it’s about 0.0000625 N, about the weight of a fat housefly, at 500 M, about .00000000001 N, like a grain of sand. If you’re trying to attract a piece of space debris at a distance of few to a few thousand km, the force is a miniscule fraction of the force of random dust or solar wind particles.


If you want to push stuff around in space without physically touching it, you need something that follows a nice distance squared force law, such as a “laser broom

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