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Ugly Truth of Space Junk
fysdt writes "Dealing with the decades of detritus from using outer space — human-made orbital debris — is a global concern, but some experts are now questioning the feasibility of the wide range of 'solutions' sketched out to grapple with high-speed space litter. What may be shaping up is an 'abandon in place' posture for certain orbital altitudes — an outlook that flags the messy message resulting from countless bits of orbital refuse. US General William Shelton, commander of Air Force Space Command, underscored the worrisome issue of orbital debris during a presentation at the National Space Symposium on April 12, 2011. In a recent conference here, Gen. William Shelton, commander of the US Air Force Space Command, relayed his worries about rising amounts of human-made space junk."
One expert is - "orbital debris expert within the Space Department at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md."
The other is - Gen. William Shelton, commander of the U.S. Air Force Space Command, who has been assigned to USAF space posts since 1976.
http://en.wikipedia.org/wiki/William_L._Shelton
Won't a large percentage of the junk re-enter the earth's orbit on its own given enough time?
Sure, for big enough values of "enough time". Which could be millions of years.
Although for some orbits not even that. In geostationary orbit I don't think the satellite will reenter earth's atmosphere before the sun goes red giant.
The higher orbits are high volume areas
Not quite. The geostationary orbit, one of the most valuable commercially, is infinitesimally thin. Any debris that goes by there requires maneuvers from the operating satellites, which burn fuel and take a toll on the useful life of the satellite.
Isn't that pretty much the premise of Quark?
Comment of the year
... we haven't been dropping crap up there for too many years, from too many spacecraft. We're sort of like Columbus and his boys worrying about a toffee wrapper that someone left behind on the beach somewhere in the Caribbean.
Wrong analogy. To continue with the Columbus theme a better analogy would be dropping off a bunch of pigs at each island you visit. When you return later you find far more than the few pigs you dropped off. Like pigs, satellite debris "breeds". 1 item of debris + 1 item of debris = *many* items of debris, where many can be many orders of magnitude larger than two.
Consider the example from the article. The number of debris items increased by 25% from a *single* event, China testing an anti-satellite weapon. While this may be a worse case event, an accidental collision between two satellites could similarly generate a cloud of thousands of debris items.
Can we get back to this in, say, two centuries when there's enough crap to worry about? We have other issues more pressing that this (oh sorry - forgot this was slashdot....thought I was in a US Government thinktank...).
A think tank would hopefully possess enough potential to realize that when TVs go blank, phones no longer make connections, ships/planes/cars can no longer navigate, etc then the average person might care.
There's not as much of a space junk problem at geostationary because there's more room up that far (the amount of room available at a given altitude, after all, increases with the square of that altitude) and we don't launch as much stuff up that far. The real problem is in Low Earth Orbit, because it's so easy to reach and there's so much less space there. Just about anything in LEO will de-orbit eventually, but it may be centuries.
and as this is in fact rocket science the problem is we have 3 different "speed bands" we are working with
1 the junk that is going slow enough to fall out of orbit
(in a more or less short period of time)
2 the stuff that is mid range speed (could take like "forever" to fall out unless somebody/something whacks it in the right direction)
3 the high speed stuff (this is very rare and is the stuff that heading out into deepish space)
the problem with 1 and 2 (mostly 2) is hitting this stuff CORRECTLY is very hard to do (ideal situation is it burns up on reentry with "does not hit anything important" as a push bet)
the worst case is you hit somebodies in service satellite or have a chunk of something wipe out a State building or something else and cause an international incident
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The definitive word on Space, is of course, the Hitchhikers Guide to the Galaxy.
"Space," it says, "is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space, listen..."
If I were God, wouldn't I protect my churches from acts of me?
The US owns nearly half of the total orbiting satellites.
http://www.ucsusa.org/nuclear_weapons_and_global_security/space_weapons/technical_issues/ucs-satellite-database.html
Total - 957
US - 436 - 10 Civil, 193 Commercial, 118 Government, 115 Military
Russia - 100
China - 69
49% of those are in LEO
Express-AM11 was knocked out by space debris, Kosmos 2251 and Iridium 33 collided destroying both.
Challenger STS-7, Endeavor STS-59, Atlantis STS-115 and Endeavor STS-118 were all hit in widows or radiators while all the shuttles, ISS and MIR were regularly hit with smaller debris.
ISS has over 100 Whipple Shields installed to reduce the impacts of small objects.