Feb. 1, 2007 — -- When the Chinese government destroyed one of its weather satellites in a military test last month, it sent a chill through the U.S. military.
And engineers say it had a serious side effect -- it increased the amount of orbiting space junk by about 10 percent.
That could mean danger -- to other satellites, and even, possibly, to astronauts on the International Space Station and future space shuttle flights.
"There's a lot of stuff up there in low-Earth orbit," said T.S. Kelso, a veteran space-surveillance analyst who is now at the Center for Space Standards and Innovation in Colorado Springs, Colo. "While we can't tell them that 'five months from now, you're at risk for being hit,' it's not unreasonable to expect that it's going to affect a lot of stuff in orbit."
The Chinese test, carried out on Jan. 11, was at once complex and very simple. An old weather satellite, passing 537 miles overhead, was targeted by a missile launched from a Chinese military base.
The missile hit the satellite with deadly precision. The missile carried no bomb because it didn't need one. The satellite was pulverized by the impact.
But what followed was chaos in space. As of today, Kelso reports that American radar is tracking at least 525 pieces of debris from the collision -- each at least the size of a baseball.
There are probably hundreds, if not thousands, of smaller ones.
The pieces are gradually spreading out in a ring around the Earth, creating a vast area where spacecraft face increased danger of being hit.
"We've already seen in the range of 500 to 600 events where some piece of debris from this one event was coming within 5 kilometers [about 3 miles] of some payload," said Kelso.
It's a growing problem. The U.S. Air Force was already tracking almost 14,000 objects in orbit.
Three times in the last 15 years, U.S. satellites have reportedly been disabled or damaged by collisions with space junk. NASA is worried enough about the problem that each shuttle crew now spends the entire day before landing taking pictures of its ship's heat shield tiles, just in case there's been a small but potentially fatal impact.