A new issue of "The Orbital Debris Quarterly News" (ODQN; Volume 10,
Issue 1, January, 2006) is now available via the NASA - Johnson Space
Center Space Sciences web server.

Please visit the ODQN site to read the latest newsletter.

http://www.orbitaldebris.jsc.nasa.gov/news...newsletter.html

While there, visit some of the other interesting areas at the Space Science web
site. The home page can be found at http://www.orbitaldebris.jsc.nasa.gov.

Space in urgent need of cleaning

Rising debris bound to cause catastrophic crashes.

More than 9,000 man-made objects currently orbit the Earth, and about two-thirds of those are debris. This includes derelict satellites, spent rockets and fragments of metal from explosions. With an estimated 5,000 tonnes of stuff flying around up there, its not surprising that US Space Command tries to track everything bigger than 10 centimetres, the size thought to present a fatal risk to spacecraft.

Liou and his colleague Nicholas Johnson used a computer model called LEGEND to predict what would happen to that space junk in the next 200 years, assuming that all space launches were halted in December 2004. That provides a 'best-case scenario', explains Liou; in reality, more and more metal is being shot into space each year.

...

The duo tracked fragments in low Earth orbit, which spans from 200 to 2,000 kilometres above the Earth's surface. Their simulation shows that without further space shots, the debris tally is stable until about 2055. But after that, the number of dangerous objects begins to rise again, as pieces of junk collide with each other and break up into smaller, yet still potentially fatal fragments.

Three such debris collisions are known to have happened since 1991 alone. The most recent, in January 2005, was between parts of a 31-year-old US rocket and a Chinese CZ-4 launch vehicle that exploded in March 2000.

"We only have one space," says Liou. "If we don't protect the space environment we might get to a stage where we can't launch satellites." The results are reported in this week's Science1.

http://www.nature.com/news/2006/060116/full/060116-9.html

Here's the problem - how do you help clean up? Obviously, designing LV's that leave as few residual pieces as possible is a start, retiring orbital spacecraft to a sensible retirement orbit is good also - but how would one go about clearing up all the mess? Something to actively limit the current number of pieces of debris up there.


Only thing I can think of is going round with a giant whipple-shield-like-fly-swot in the most populated orbits - perhaps something that could be deployed from a small size, and consist of a few layers of typical whipple-shield material covering as large an area as possible to 'wipe up' the mess.

Or is that the wrong tactic - would it make more sense to track these objects very accurately and try and 'fry them' using lasers on the ground? turn them into a little cloud of vapour that can disperse.

I cant think of a means by which we can solve the problem, all we can do is try to slow up the worsening of it.

Doug

I think the whipple shield idea would be a big mistake. For starters I can't see how you could build it to contain the debris so I reckon you'd just end up with more chaotic debris. On top of that most of the problematic stuff is relatively big and a single impact would probably kill your shield and your cleaner.

The laser idea might be a runner for anything that isn't huge. A Geostationary laser platform might not be a bad idea if you could build such a beast (which I doubt). Use the laser to slow\vapourise the debris as it crosses the terminator so you minimise the risk of zapping us innocent saps on the ground. That way you use the atmosphere to do the bulk of the cleaning up work. Firing from the ground you'd need to either fully vapourize things which is almost impossiblly hard for any beam that has first travelled through the atmosphere.

The major problem with that is that it would require just the sort of technology that Star Wars* required and you can just imagine the uproar that would cause. To be honest I don't think I'd be too keen on having such a beast out there myself.

* The Ronald Reagan version not the Gene Roddenberry variety obviously.

How about sending "walls" of aerogel around Earth to collect small debris like Stardust did, then letting them burn up in the atmosphere?

Though I can imagine scientists might want to examine those sheets for interesting debris first.

That's a good idea - thin-ish but large panels of aerogel that all fold out to form as large a sheet as can be squeezed into a launch vehicle, only problem is getting it to sit facing the direction of motion instead of weather-vaning in the upper atmosphere.

Doug

Why not develop an ion powered tug-boat type vehicle that has the ability to rendevous with a given chunk of debris and put it in a giant baggy with the previously collected chunks in similar orbits. Eventually you'll have five big bags instead of 9000 small parts (probably 100,000 if you get down to a centimeter).

My thought is that you might want to leave these bags in orbit, since they will be full of materials that were very expensive to get into orbit (energy-wise), and so any of this stuff that can get recycled in a few decades will be appreciated (my guess).

I'm guessing you'd want to launch a dozen or so of these tugs.

NPR Science Friday covered this last week - you can listen here
Podcast

Space is running out of space

The so-called "void" is becoming so crowded, a senior US expert is
calling on countries to begin planning how to manage space traffic.

http://www.1to1Catalog.com/apps/redir.asp?...A&tid=WiceefhDA

TECH SPACE

- Russian Telecom Satellite Fails After 'Sudden Impact'

http://www.spacedaily.com/reports/Russian_...den_Impact.html

Moscow, Russia (SPX) Mar 30, 2006 - The Russian Satellite Communications
Company's Express-AM11 telecommunications satellite suffered a sudden failure on
Wednesday. "At present, providing services via the Express-AM11 satellite is
impossible," the company said in a statement.

Russian Satellite Failure Caused By Space Garbage

http://www.spacedaily.com/reports/Russian_...ce_Garbage.html

Solution 1: Acme Space Magnet

Solution 2: Send up Homer Simpson, tell him the debris is potato chips.

Solution 3: Nanobots gather debris and build new space station.

List can be longer...

Solution 4: Powerful Laser Cannon (in space or on Earth with adaptive optics) recycled from "star wars" project, vaporizing the debris like in a videogame.

Solution 5: deviate a comet in the L1 libration point and wait that it's gas will slow down ALL objects anticipating their fall on Earth

Unfortunately, latter solution will hit also functioning satellites (included the hundred-billion $ ISS)... but the good side effect is to clean space and allow safe construction/operation of a space elevator!
At this point, we can start to re-populate space with garbage...

Dilo:

That set me wondering - perhaps the way out of Mike Griffin's ISS quandry is an 'insurance job' on the ISS. A nice collision, get the lads off in the Soyuz, declare it a loss and de-orbit it? No recriminations, 'these things happen', 'nice to have met you' and 'goodnight'.

Bob Shaw

I like this one...NASA could charge people to take shots at debris in space...of course, they'd have to program it so it wouldn't allow anyone to shoot the non-debris (like ISS).

That's a good idea, but it wouldn't need to be aerogel. Remember, the aerogel was used for it's capacity to capture the impactors without deforming the particles. I would guess that a denser substance could be used that would operate at a higher efficiency. Some kind of self-inflating, self-curing foam perhaps that operates on the same principle as spray-foam insulation you can buy at the hardware store. Such a system would save on volume for the initial orbital placement.

I'm imagining a succession of nested nets or cones shaped like meterological windsocks that could be unfurled, with layers of something like aerogel or a silicate based foam between the layers.

Perhaps a laser on the space station could be used to ablate small amounts of material from the leading surfaces of undesired orbiting materials and speed up the decay of their orbits.

Letting space command track the results would allow items to be preferentially dropped in the Pacific and would also avoid collisions with useful assets.

{In the extremely unlikely event no one else has thought of this, please PM me for my address to send the royalty checks. }

The ISS isn't debris? Damn, there I was, collecting AA batteries and tinfoil for the mirrror...

Bob Shaw

If you were to put a giant laser in space, how would you prevent whoever controlled it from pointing the thing at Earthly objects of interest? A thing like that would immediately be perceived as a weapon. Thus forcing other countries to launch their own lasers for "space junk disposal" purposes.
Inevitable militarisation of space, if you ask me. That thing would surely serve a purpose as an anti-ICBM shield well before being used for benign purposes of garbage cleanup.

For sure, ugo!
Correct if I'm wrong, initial USA "star wars" plans included such kind of stuff and also space based X-ray cannons powered by nuclear bombs... (based on your avatar, you should know this matter! )

Watch the Skies… For Junk

As head of NASA's Orbital Debris Program Office, Nicholas L. Johnson keeps tabs on deadly flying garbage, aka space junk.

By Amos Kenigsberg

June 05, 2006 | Astronomy & Physics

http://www.discover.com/web-exclusives/spacejunk/

How much junk is out there?

For things bigger than 10 centimeters, there are about 8,000. Things that are larger than 1cm, we're talking a few hundred thousand. If you're talking things larger 1mm, we're talking a hundred million.

GEO debris and interplanetary dust: fluxes and charging behavior

http://arxiv.org/abs/astro-ph/0609341

100,000 Pieces Of Trash In Space Poses No Shortage Of Risks

http://www.spacemart.com/reports/100000_Pi..._Risks_999.html