China space junk explosion
Posted: Thu Sep 06, 2007 11:45 pm
I remember hearing about the missle test but never thought about the mess they would creat. Also according to other reports i read there was a much larger number of smaller untrackable pieces that can cause damage as well
BEIJING — Scientists have concluded that a Chinese missile test in January that smashed an aging weather satellite was the messiest space event ever, adding more than 1,500 big scraps of debris to a junkyard that's orbiting the Earth.
They said it may only be a matter of time before a weather, communications or other satellite — or the manned International Space Station — slams into space rubbish.
The debris travels through space at about 17,400 mph, 10 times faster than a bullet from a high-powered rifle and 100 times faster than a race car.
A millimeter-sized orbiting fleck of aluminum can have the kinetic energy of a bullet against a billion-dollar satellite, said Fernand Alby, the chief of debris monitoring at the French space agency, CNES.
"The breakup of Fengyun-1C is by far the most severe satellite breakup ever in terms of identified debris," said Nicholas I. Johnson, the chief scientist for orbital debris at the Lyndon B. Johnson Space Center in Houston.
The missile that China launched from the Xichang space center obliterated a defunct Fengyun-1C weather satellite and showed the country's space might.
Johnson said the U.S. Space Surveillance Network later tracked more than 1,500 large shards from the shattered Chinese satellite, most of them measuring 4 inches — the size of a teacup — or larger.
Smaller debris is far more numerous.Compounding the debris problem, the upper stage of a Russian Proton rocket exploded over Australia on Feb. 19, littering the skies with as many as 1,000 pieces of rubble.
At the time of the Chinese test, NASA radar was tracking roughly 10,000 large pieces of debris in space, so the debris from the 1,650-pound Fengyun-1C increased by about 15 percent the number of items that NASA must track to avoid collision.
Some of the debris from the Chinese satellite already has fallen to Earth, but Johnson of NASA said most would "remain in orbit for many decades, up to a century or more."
As NASA's tally has climbed, so has anxiety among operators of commercial satellites and specialists at European and U.S. space programs.
France operates 14 satellites in low Earth orbit, and now deals with high-risk conjunctions — near-misses in space closer than 1 mile — with space fragments once every two weeks on average.