Steve Wozniak announces private space company to clean up space debris in orbit

> However, for existing dead satellites & debris that is above atmospheric decay in reasonable times, I wonder if it would actually be more effective/efficient (in terms of cost, delta-V, scheduling, etc.) to 'herd' the junk into a more out-of-the-way location for future use. It seems once on-orbit manufacturing starts, it'd be useful to have a lot o high-quality material up out of the gravity well, and all of that stuff has already had huge investment to get it to orbit in the first place.

Basically none of that is practical. Moving anything in space requires fuel. Changing a satellite's orbit from A to B requires the same amount of fuel as going from B to A. Going from A to B and then back to A takes twice the fuel. If you pick up more mass at B, you actually need more fuel to get back to A. You also need fuel to rendezvous with your fuel depot where you can get all the fuel for these trips.

Every rendezvous has a probability of failure. The more rendezvous you perform the more likely it is something bad will happen. Satellites aren't usually super sturdy structures because they're optimizing for mass. So some satellite herder needs to spend a lot of extra fuel matching the target's spin rate and velocity so capturing it doesn't cause it to break apart.

Then there's the orbital manufacturing. Even if you managed to capture hundreds of satellites and herd them into some holding orbit, you've got a bunch of heterogeneous parts clumped together. You'd need to disassemble a bunch of devices that weren't meant to be disassembled. Even if you get them disassembled they're a bunch of finished packaged parts. They're not going to be reusable so they'd need to be melted down. Now you need smelters and centrifuges and every other chain in recycling materials to base feedstocks.

That's all an absurd level of complexity and danger compared to just de-orbiting a satellite. The costs don't even compare. Your proposal would be phenomenally expensive if it was practical. Satellite clean up is highly impractical and expensive but still orders of magnitude more practical and cheaper than the things you're talking about.

It's an American accent, but with rhotacism, a type of speech impediment. He sounds vaguely British at times because of the tendency for "R" to come out sounding like "W"

https://en.wikipedia.org/wiki/Isaac_Arthur

A couple of ideas that come with little knowledge, so take it with a big grain of salt:

1. "Electromagnetic Missile" with trajectory who's apogee is just below the targeted space junk. Turn on the electromagnet when just below the space junk to drag down its trajectory slightly, or even down to a de-orbit trajectory. Obviously, this only works with satellites built with magnetic materials. It may just be my outsider's perspective, but non-orbital missiles seem much easier and cheaper than rockets that go into orbital trajectories. Handling the return of the missile is tricky, perhaps it can also self-detonate fairly high in the atmosphere.

2. Ion engines or space sails driven tugs for use in getting to the space junk. My understanding is ion engines have a really favorable specific impulse. An optional chemical engine could be used to quickly de-orbit the tug upon reaching the satellite. Another idea to speed up de-orbit without requiring the tug the whole way would be a spring that would "push" the junk once it reached it, throwing it into an orbit that would more quickly drop it into the atmosphere. Newton could be used to our advantage to also push the tug into a new orbit to reach the next junk satellite sooner.

Obviously, arm-chair rocket scientist here, so feasibility of the above ideas can probably quickly be dis-proven.

Can you use the junk's energy to power the cleaner? Imagine this: the cleaner has a big spring on the back of it. The spring is slowly compressed using solar power. The orbiter grabs a piece of junk, and then launches it backwards. The cleaner now has gained some of the energy from the junk, and the junk has lost energy.

First, a lot of space debris is small. I'm talking like flecks of paint. That's an issue at high speed and this has hit the ISS [1].

Obviously there's the conservation of momentum to deal with. That fleck of paint has a decent amount of momentum but that's fairly easily absorbed by a couple of tons of material fixed to an otherwise rigid body.

You'd probably attach it via cables and if, somehow, enough momentum was delivered to that "paddle" that it would tear off the cables would just let it go.

If the paddle is fixed to the ring and is let go, it's just going to fall to Earth even with any added momentum, in which case it'll burn up in the atmosphere.

The more dangerous debris is larger stuff. Like there are dead parts of rockets, even smaller stuff like bolts. These pose extra challenges but a lot of the same principles apply.

[1]: https://www.csmonitor.com/Science/2016/0513/Space-debris-dan....