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This makes no sense to me. Most talk about "recycling" space junk forgets that it's a lot like recycling bullets on a battlefield. The mass is there, but good l

This makes no sense to me. Most talk about "recycling" space junk forgets that it's a lot like recycling bullets on a battlefield. The mass is there, but good luck catching it.

Terr_ 3y ago
I imagine there is quite an investment simply bringing all the stuff together into identical orbits. Like "waste heat", part of the problem is the disorder. If all you need is mass, it might be more profitable to send a robot to a small asteroid and nudge it on its way towards us.
- lxgr 3y ago
  > simply bringing all the stuff together into identical orbits This only works for orbits of similar inclination, unfortunately. Shifting orbital planes is prohibitively expensive in terms of energy due to the conservation of angular momentum [1] and the rocket equation. It might work for similar-enough orbits, though. [1] https://orbital-mechanics.space/orbital-maneuvers/plane-change-maneuvers.html https://orbital-mechanics.space/orbital-maneuvers/plane-chan...
  - esperent 3y ago
    We don't have to solve all of it, only a significant amount. Also, perhaps the most important thing to solve is a proof of concept - that we can remove any space junk. From there we can start to compare and refine ideas to figure out what the possible solutions are.
adewinter 3y ago
In addition you're attempting to recycle space junk ("bullets") when you're quite literally standing on planet packed to rafters with junk. The energy required to harvest the material in orbit makes it extremely hard to make a case that it is economical.
- imtringued 3y ago
  You didn't read the article. The point is that you want to use the space junk as a mass filler for your skyhook. The skyhook needs a lot of mass, a thousand times more mass than the payload. To boost a 100 ton payload, you need a 10000 ton skyhook. Junk on earth is worthless as that has to be launched into LEO. My biggest concern however is how they are going to keep the skyhook rotating. If it needs energy from earth the entire concept is kind of meaningless.

This makes no sense to me. Most talk about "recycling" space junk forgets that it's a lot like recycling bullets on a battlefield. The mass is there, but good luck catching it.

Terr_ 3y ago

I imagine there is quite an investment simply bringing all the stuff together into identical orbits. Like "waste heat", part of the problem is the disorder. If all you need is mass, it might be more profitable to send a robot to a small asteroid and nudge it on its way towards us.

lxgr 3y ago
> simply bringing all the stuff together into identical orbits This only works for orbits of similar inclination, unfortunately. Shifting orbital planes is prohibitively expensive in terms of energy due to the conservation of angular momentum [1] and the rocket equation. It might work for similar-enough orbits, though. [1] https://orbital-mechanics.space/orbital-maneuvers/plane-change-maneuvers.html https://orbital-mechanics.space/orbital-maneuvers/plane-chan...
- esperent 3y ago
  We don't have to solve all of it, only a significant amount. Also, perhaps the most important thing to solve is a proof of concept - that we can remove any space junk. From there we can start to compare and refine ideas to figure out what the possible solutions are.

adewinter 3y ago

In addition you're attempting to recycle space junk ("bullets") when you're quite literally standing on planet packed to rafters with junk. The energy required to harvest the material in orbit makes it extremely hard to make a case that it is economical.

imtringued 3y ago
You didn't read the article. The point is that you want to use the space junk as a mass filler for your skyhook. The skyhook needs a lot of mass, a thousand times more mass than the payload. To boost a 100 ton payload, you need a 10000 ton skyhook. Junk on earth is worthless as that has to be launched into LEO. My biggest concern however is how they are going to keep the skyhook rotating. If it needs energy from earth the entire concept is kind of meaningless.