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

independent.co.uk

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

#161

Post by theshrike79 »

There was a hard-scifi manga/anime about this almost 20 years ago: https://en.wikipedia.org/wiki/Planetes

"The story of Planetes follows the crew of the DS-12 "Toy Box" of the Space Debris Section, a unit of Technora Corporation. Debris Section's purpose is to prevent the damage or destruction of satellites, space stations and spacecraft from collision with debris (so-called "space debris") in Earth's and the Moon's orbits. They use a number of methods to dispose of the debris (mainly by burning it via atmospheric reentry or through salvage), accomplished through the use of EVA suits."

Basically space garbage men =)

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

#163

Post by deelowe »

cletus wrote: post #140
mc32 wrote: post #51

Earlier quoted context omitted.

At the speeds those things whiz by, what sort of materials are there that can withstand impacts and not create more debris? Or do they try to do it via relative speeds and say let them hit the "paddle" at 50mph? And in that case, might it not be more effective to have hunting "nets" to collect the objects?

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 d…

I thought larger parts aren't as big of an issue in the majority of cases as most orbits aren't stable and they'll eventually fall to earth or be ejected into outer space.

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

#166

Post by LeifCarrotson »

babypuncher wrote: post #117
SonicScrub wrote: post #26

Earlier quoted context omitted.

Requiring de-orbiting at EOL would destroy their business no? Also EOL de-orbiting works great for low-altitude orbits, but becomes exponentially more difficult with higher orbits. It is pretty much impossible with the very valuable geostationary orbital slots.

I am by no means a rocket scientist, but wouldn't a de-orbiting requirement be as simple as including a few small chemical thrusters with a dedicated fuel source reserved for de-orbiting? I have no idea how much force it takes to actually move a given amount of mass out of orbit, and I assume it is different depending on the height of that orbit. So maybe doing this would simply add too much weight in the form of fue…

Orbits are circles or ellipsoids, not spirals.

It takes a ton (possibly literally) of propellant to change your orbit from a circle in GEO to an ellipse that intercepts the atmosphere. If you don't have enough, you've not put it in a deorbiting spiral, simply an oval that will stay up for about as long as the original satellite's circular orbit.

Rocket scientists work in terms of 'delta V', meaning an amount of energy gives you a particular change in velocity. GEO to LEO takes on the order of 6 km/s (oversimplifying because orbital mechanics are complicated), meaning you need a rocket engine that's capable of accelerating your satellite from 0 to 13,400 miles per hour.

That's really expensive and difficult.

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

#167

Post by rich_sasha »

dotancohen wrote: post #84
rich_sasha wrote: post #77

Earlier quoted context omitted.

Unless you vapourise the debris, you just turned it into chunks of smaller debris, travelling at the same velocity.

If you can ablate the leading surface (if the object is not spinning quickly, which honestly is unlikely) then the ejected plasma may push the perigee either into the atmosphere or at least to a higher-drag altitude.

...and this only works at LEO where, I hear, it is less of an issue.

Though it seems maybe still an issue, judging by all the shenanigans that the ISS has to do to avoid being shot down.

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

#168

Post by toss1 »

giantrobot wrote: post #132
toss1 wrote: post #88

So many comments here focusing on de-orbiting. Of course for any new satellite, end-of-life de-orbiting should be a part of the initial design, engineering, & build. 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 loca…

> 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 s…

Thanks! I hadn't considered the risks of multiple rendevous maneuvers — probably more risky than shooting some kind of net around the target with a drag sail attached or something.

Like a magnified version of most modern mfg, it just bugs me that the easiest way to deal with failures is to just trash the thing rather than reuse/repair.

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

#169

Post by BitwiseFool »

andjd wrote: post #55

Does anyone else see Wozniak as the headliner and shrug? He has no track-record of successful companies since Apple. Why is this news and why did it hit the front page of HN?

I still admire the man for his accomplishments and the role he played in shaping the modern world of computing. But I also recognize that his current role is to provide brand recognition for longshot companies.

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

#170

Post by orbital-decay »

cletus wrote: post #18

So here's a potential business model for this: salvage rights. When ships sink, the owner generally still retains ownership of any property. Sometimes the location of the wreck is known. Sometimes it needs to be found. It can cost a lot of money to find a wreck and recover any property. So salvage rights are a principle of maritime law such that whoever does this is entitled to a reward commensurate with the value of…

Even if someone solves the technical part (cheap recovery), there are multiple practical problems with salvaging.

1. Satellites don't have much to salvage at EoL, they are typically obsolete at this point, at least for their main purpose. Their components degrade as well - space is a fairly aggressive environment and they aren't designed to be reusable.

2. They often contain highly regulated components that have tight export restrictions.

3. They might contain state or trade secrets and recovering by a third party is highly undesirable.

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