Much Ado about Space Debris
Byline: James Hackett, THE WASHINGTON TIMES
China's deliberate destruction of one of its own satellites in a January test of an anti-satellite (ASAT) weapon has led to much hand-wringing about the creation of space debris, reinvigorating the opponents of weapons in space. Orbiting debris is dangerous, but the danger has been greatly exaggerated and is no reason for new unenforceable arms control agreements.
When the space age began 50 years ago there were no man-made objects in space. Since then, Space Command has tracked more than 25,000 objects of baseball size or larger. More than 10,000 have fallen into the atmosphere and disintegrated or landed, but in 50 years not one person anywhere on Earth has been killed or injured by falling debris.
Space debris is only slightly more likely to strike one of the 850 active spacecraft. Most are in low Earth orbit below about 800 miles. These operational spacecraft are only 6 percent of the objects tracked. The rest is space junk that includes inactive satellites, spent rockets, debris from exploding rockets and just plain trash. Space Command monitors debris to identify threats and alerts operators of satellites to move out of the way if they appear to be in danger.
Some 80 percent of debris orbits between 500 and 600 miles altitude. The Chinese test, at 527 miles, created more debris right where traffic is heaviest. Air Force Space Command is tracking more than 1,000 pieces of debris from the Chinese test, plus 14,000 that were there before. So far, none has hit an active spacecraft. In fact, over the last 50 years there have been only three documented debris impacts with operational spacecraft, and none have been destroyed.
A Space Command Web site describing the Space Surveillance Network that tracks debris notes there is only a small amount in the low orbits of the space shuttle and space station, and gives a worst-case estimate of 1 chance in 10,000 years of a piece of debris of baseball size or larger hitting either one.
Even in the debris-heavy area around 500 miles altitude, Space Command says normally there are only three or four objects orbiting in an area equivalent to the airspace over the continental United States up to an altitude of 30,000 feet. Thus, it states, the likelihood of a collision is very small.
Now there are reports U.S. intelligence agencies knew about and monitored Chinese preparations for the ASAT test, but senior administration officials decided to say nothing to deter Beijing in orderto protect intelligence methods. …