Depends on the composition of the material and the strength of the magnet ;^).
http://en.wikipedia.org/wiki/Space_junk
http://www.orbitaldebris.jsc.nasa.gov/
(before the Chinese event)
Posted on 02/07/2007 5:13:16 PM PST by Fitzcarraldo
For decades, space experts have worried that a speeding bit of orbital debris might one day smash a large spacecraft into hundreds of pieces and start a chain reaction, a slow cascade of collisions that would expand for centuries, spreading chaos through the heavens.
In the past decade or so, as scientists came to agree that the number of objects in orbit had surpassed a critical mass - or, in their terms, the critical spatial density, the point at which a chain reaction becomes inevitable - they grew more anxious.
Early this year, after a half- century of growth, the federal list of detectable objects (4 inches wide or larger) reached 10,000, including dead satellites, spent rocket stages, a camera, a hand tool and junkyards of whirling debris left over from chance explosions and destructive tests.
Now, experts say, China's test Jan. 11 of an anti-satellite rocket that shattered an old satellite into hundreds of large fragments means the chain reaction will most likely start sooner.
If their predictions are right, the cascade could put billions of dollars' worth of advanced satellites at risk and eventually threaten to limit humanity's reach for the stars.
Federal and private experts say early estimates of 800 pieces of detectable debris from the shattering of the satellite will grow to nearly 1,000 as observations continue by tracking radars and space cameras. At either number, it is the worst such episode.
Today, next year or next decade, some piece of whirling debris will start the cascade, experts say.
"It's inevitable," said Nicholas Johnson, chief scientist for orbital debris at NASA. "A significant piece of debris will run into an old rocket body, and that will create more debris. It's a bad situation."
Geoffrey Forden, an arms expert at the Massachusetts Institute of Technology who is analyzing the Chinese satellite debris, said China perhaps failed to realize the magnitude of the test's indirect hazards.
Forden suggested that Chinese engineers might have understood the risks but failed to communicate them. In China, he said, "the decision process is still so opaque that maybe they didn't know who to talk to."
In April, Beijing is to play host to the annual meeting of the Inter-Agency Space Debris Coordination Committee.
Donald Kessler, a former head of NASA's orbital-debris program and a pioneer analyst of the space threat, said Chinese officials at the forum would probably feel "some embarrassment."
Cascade warnings began as early as 1978. Kessler and his NASA colleague, Burton Cour- Palais, wrote that speeding junk that formed more junk would produce "an exponential increase in the number of objects with time, creating a belt of debris around the Earth."
A solution to the cascade threat has been suggested, but it is costly. Johnson of NASA has argued that the only sure answer was environmental remediation, including the removal of large objects from orbit.
I know. I'm just so friggin' sick and tired of the constant hysterical, hyperventilating, apocalytic, wildly exaggerated drumbeat of gloom and doom and we're all gonna DIE!!!!! screeching that comes from the media without even the slightest pause for air.
All this junk will reflect sunlight back into space causing dangerous global cooling.
Assuming an average altitude of 1000 miles, the area covered by this space junk is about 255 million square miles. With 20,000 pieces of space junk, that works out to one piece of space junk for every 12,700 square miles. That's about one piece of junk for every area the size of the state of Maryland.
Depends on the composition of the material and the strength of the magnet ;^).
http://en.wikipedia.org/wiki/Space_junk
http://www.orbitaldebris.jsc.nasa.gov/
(before the Chinese event)
But the orbiting junk travels fast (5 miles/sec) so it sweeps out large volumes per unit time and would impact other satellites at high relative velocity in the miles/second range, creating more debris in a cascading effect / chain reaction.
The Kessler Syndrome is a scenario, proposed by NASA consultant Donald J. Kessler, in which the volume of space debris in Low Earth Orbit is so high that objects in orbit are frequently struck by debris, creating even more debris and a greater risk of further impacts. The implication of this scenario is that the escalating amount of debris in orbit could eventually render space exploration, and even the use of satellites, too prone to loss to be feasible for many generations.
The Kessler Syndrome is especially insidious because of the "domino effect." Any impact between two objects of sizable mass will create additional shrapnel debris from the force of collision. Each piece of shrapnel now has the potential to cause further damage, creating even more space debris. With a large enough collision (such as one between a space station and a defunct satellite), the amount of cascading debris could be enough to render Low Earth Orbit essentially impassable.
Every satellite, space probe and manned mission has the potential to create space debris. As the number of satellites in orbit grow and old satellites become obsolete, the risk of a cascading Kessler Syndrome becomes greater.
The Kessler Syndrome presents a unique problem to human space travel. Space debris is very difficult to deal with directly, as the small size and high velocities of most debris would make retrieval and disposal impractically difficult. Given thousands of years, most debris in Low Earth Orbit would eventually succumb to air resistance in the rarefied atmosphere and plunge to the Earth. If magnetically susceptible, the debris could fall in a few decades due to the drag of the Earth's magnetic field.
To minimise the chances of damage to other vehicles, new vehicles and satellites are frequently required to demonstrate that it can be safely disposed of at the end of its life, for example by use of a controlled atmospheric reentry system.
Fortunately at the most commonly used Low Earth Orbit's residual air drag helps keep the zones clear. Altitudes under 300 miles will be swept clear in a matter of months.
I'd sign up to be a space garbageman. Sounds fun.
Here you go:
"...If magnetically susceptible, the debris could fall in a few decades due to the drag of the Earth's magnetic field..."
My guess is a lot of that metal is aluminum and magnesium, which are minimally affected by magnets.
Collisional cascading: The limits of population growth in low earth orbit
Donald J. Kessler
NASA/Johnson Space Center, Houston, TX 77058, U.S.A.
Available online 25 November 2002.
Abstract
Predictions have been made by several authors that random collisions between made-made objects in Earth orbit will lead to a significant source of new orbital debris, possibly within the next century. The authors have also concluded that there are a number of uncertainties in these models, and additional analysis and data are required to fully characterize the future environment. However, the nature of these uncertainties are such that while the future environment is uncertain, the fact that collisions will control the future environment is less uncertain. The data that already exist is sufficient to show that cascading collisions will control the future debris environment with no, or very minor increases in the current low Earth orbit population. Two populations control this process: Explosion fragments and expended rocket bodies and payloads. Practices are already changing to limit explosions in low Earth orbit; it is now necessary to begin limiting the number of expended rocket bodies and payloads in orbit.
Experts? Try idiots. Even LEO space is HUGE.
What crappy writing. NYT subscribers get a bonus in my book for being able to read, but it ends just about there.
My idea is a huge ball of styrofoam that would sweep up objects then reenter after orbital decay, which would be rapid for a large low density object.
Not sure how that would work out!
Problems:
Low encounter rate.
Engineering a "capture density" for the styrofoam.
Getting it up there.
That reminds me. Did everyone see the superbowl ad with the "moon mission" theme? They depicted zero-g effects on the lunar surface. To me, this sort of thing is a scary peek into the abyss of ignorance.
Well, doc....you were peeking into what has long been called a "boob tube."....... =P
Men Into Space, later syndicated as Space Challenge, used for its plots many technical and human problems anticipated by engineers and planners. For example, the show depicted attempts to refuel spacecraft by tanker in orbit, construction of a space telescope, an experiment to dispose of high level atomic waste by launching it into the sun, the search for life-sustaining frozen water on the moon, exploration and destruction of an asteroid whose orbit threatened Earth, and exo-fossil evidence of extraterrestrial life.
The episode that sticks in my mind was some kind of rescue during a lunar exploration that laboriously depicted the low-g lunar gravity.
1960
It is all orbiting and in the same basic direction. It is not as if the stuff were all flying about randomly. I am sure that satellite defense systems are in development-some might be deployed on some satellites- systems that recognize pieces that are on collision course and can change orbit just a tad or even repel small bits. I know that many of the satellites are able to change orbit and can be repositioned to look at different parts of the earth.
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