More on Orbital Space Debris

wvanhuffel writes "This is a call for /.'s to put their thinking caps on. The US Airforce, NASA and other agencies are looking for ideas to find and eliminate threats from space debris to craft (space, in the use of). Personally I like the idea of "robots to serve as roving garbage scowls" - my question is "How do they identify 'garbage'?" - Would the ISS qualify?" I don't know what happened to the laser broom.

Comments

A lot of work

[theolein]

IIRC there are about 200 000 objects ranging from milimeter size pieces to fat chunks of metal in orbit around our planet. Someday one is going to take out a spacecraft or satellite or damage one seriously. Obviously, it is going to be a lot of work to get rid of these pieces of scrap. So my carefully thought out proposition ;)...
1.Catalogue them -- A database with all known objects and their orbits is the obvious first step
2.Build a sateliite with a relatively low power laser, charged by solar panels. An alternative would be a simple kind of large, thick metal "shield" that would simply get in the way of the space debris.
3.Place a ion engine on the craft.
4.Write software that would automatically select the nearest target from the db and move the satelite into position to evaporate or impact with the debris.
5.Very importantly, have an operator or command center that would be required by the software to OK each impact so that the satelite doesn't get misused or highjacked.
6.If using the satelite with a big metal "target shield", eventually the shield will become useless. It can be pushed into reentry by the ion engine and can then burn up on reentry, the ion engine then climbs back into normal orbit and is fitted out with a new shield by a drone rocket.
7.It will take many years but will start to show progress over time. Good that it will give the operators in the command center work and enable them to read books, playgames etc inbetween hits.

How about aerogel?

[MouseR]

NASA is already using AeroGel in the StarDust mission to collect high-velocity particles.

Thick enough, it could be used to capture those tiny bolts and fragments they can't track by radar.

Also, one of their concerns about using lasers to zap bigger debris was the fear of generation bazillion smaller particles that couldn't be collected or tracked thereafter.

Why not create an autonomous robot that circles the globe, zap the objects it can while collecting the smaller debris in an AeroGel fish net?

Think it won't hold up to the task? Check out the photos of AeroGel. The fluffy thing can hold up a brick!

Collect it as ballast for tether/space elevator

[apsmith]

The Spring 2002 issue of Artemis Magazine had an excellent article on this by Henry P. Cate, Jr., titled the "Junk Man's Ladder". The idea is to put up a tether (many kilometers long "rope") in a convenient orbit with electrodynamic lift capabilities and some thrust, move it around to "catch" space debris, and move the junk up to the center of mass of the tether, to give it greater stability. Tethers like this are form of "space elevator", able to lift move things from low to high orbit with high efficiency. More on orbital tethers can be found at Tethers Unlimited Inc., run by Robert L. Forward and Robert P. Hoyt (who I was fortunate to have dinner with a couple of months ago).

Are giant Nets too low tech?

[Uttles]

Get some sort of mesh "net" made out of whatever metal is deemed strong enough and have these nets surround whatever it is you don't want to get damaged. I know it sounds really low tech and bulky, but hell it's cheap and would probably work.

An Alchemist's Solution

[RhettLivingston]

First and foremost, any solution needs to consider the economic factor. A solution that pays for itself will be a hands down winner.

Second, it seems like many of the solutions here would create more debris than already exists. A single large satellite is far simpler to track and avoid than a few thousand pieces of that large satellite. Unless your lasers or other weapons completely convert the debris into energy, you're wasting your time. Even if they force the debris toward Earth, the question would remain of "how did they do it"? The answer is by vaporizing matter which blasted away in the opposite direction. That matter is now not only debris in space, but untrackable debris. Even a paint fleck can do (and has done) serious damage to another orbiting object.

Third, THIS SPACE JUNK HAS VALUE!!! If its matter, and its in orbit, it is worth thousands of dollars a pound. It blows my mind everytime they guide something down that took millions too get up there instead of coming up with a way to get stuff into a parking orbit. Eventually, probably even today, there should be enough materials in space to justify manufacturing in space instead of sending more stuff up.

Steps we should take to turn this lead into gold include a) all future items launched should have provisions to reach an orbiting factory/storage facility at the end of their expected life. b) they need to all have provisions for capture via forces instead of mechanical means. This might mean adding magnetic materials or something. This way, an orbiting vehicle could capture them without contact that could cause further scattering of debris. c) software needs to be developed that can calculate capture plans for multiple objects that utilize the energy (stored in the momentum) of the objects captured effectively to help reach the next object and eventually get back to the orbiting factory/storage facility. Sort of like a game of 3D billiards. d) automated recycling and manufacturing technologies need to be developed to turn these raw materials into useful things like airtight habitat shells. At least initially, we'd probably have to keep bringing the high tech chips and stuff up the hard way, but the heavy shells and stuff could likely be very effectively manufactured in space. Things like girders for the space station should be relatively easy to do.

Nanosatellites

[Troodon]

BBCnews reported some time ago on such a posible role for Surrey Satellite Technology's nanosatellite SNAP program. A swarm of cheap (at about 100,000 UK sterling) manuverable tiny satellites that can latch onto and gradually deorbit junk.

How though could such carry enough reaction mass to actually slow something down enough? Info on its propulsion system is here (pdf). Could you just do it via its flywheel? Or use such to cluster together junk for collection by something bigger?I could certainly see a role as a beacon to actively tag stuff (on the net even!)rather than relying upon constant ground based monitoring.

reality check

[stinky wizzleteats]

The article is a bit heavy on the space-junk media hype. The practical answer is to let nature take its course and work toward prevention.

Any method of attempting to destroy debris isn't going to be practical. Giant debris collectors deliberately placed in dangerous orbits are likely to simply be smashed to pieces rather than gather any meaningful quantity of debris. Laser systems could vaporize metal fragments, but this vapor will simply congeal into globlets and cool into the space equivalent of bird shot. Until we develop gravity disruption fields, there is no effective way to affect the orbits of debris. The best bet is to wait the problem out. LEO is unstable. The Earth's atmosphere bulges significantly during solar maximums, and this drag has the effect of cleaning out the spacelanes within a reasonable period of time. In time, the problem (at least at LEO) will take care of itself if we can stop adding to it.

I'm pretty sure the following is being done, but there should be restrictions on any mass accelerated to orbital speeds. Specifically:

• Upper stages, shrouds, and other spacecraft assemblies accelerated to orbital speeds must include a system to deorbit once the payload has been delivered.
• All payload devices must have an end-of-life deorbit procedure so that 100% of the mass accelerated at the start of the project is safely deorbited.
• Spacewalks and other activities involving the manipulation of assemblies/parts at orbital speed must include some sort of recovery system for parts that "get away". A bolo-style net gun comes to mind, as does a retaining net set up around the perimeter before the procedure begins. Indeed, small robotic spacecraft interceptors could be designed to chase down the odd foot clamp, grab it, and return the item to the work area.

Or, we could just use the Q solution. Simply change the gravitational constant of the universe.

silicon foam

[roman_mir]

Some sort of silicon foam that is pressurized in a gigantic can and when sprayed forms a cloud that hardens into some bubbly sticky material. Debris can hit this from any side and either stick to it or penetrate it and decellerate while inside and maybe not even exit it on the other side.