Two big communications satellites collided in the first-ever crash of two intact spacecraft in orbit, shooting out a pair of massive debris clouds and posing a slight risk to the international space station.
NASA said it will take weeks to determine the full magnitude of the crash, which occurred nearly 500 miles (805 kilometers) over Siberia on Tuesday.
"We knew this was going to happen eventually," said Mark Matney, an orbital debris scientist at Johnson Space Center in Houston.
NASA believes any risk to the space station and its three astronauts should be low. It orbits about 270 miles (435 kilometers) below the collision course. There also should be no danger to the space shuttle set to launch with seven astronauts on Feb. 22, officials said, but that will be re-evaluated in the coming days.
The collision involved an Iridium commercial satellite, which was launched in 1997, and a Russian satellite launched in 1993 and believed to be nonfunctioning. The Russian satellite was out of control, Matney said.
The Iridium craft weighed 1,235 pounds (560 kilograms), and the Russian craft nearly a ton.
No one has any idea yet how many pieces were generated or how big they might be.
"Right now, they're definitely counting dozens," Matney said. "I would suspect that they'll be counting hundreds when the counting is done."
As for pieces the size of micrometers, the count will likely be in the thousands, he added.
There have been four other cases in which space objects have collided accidentally in orbit, NASA said. But those were considered minor and involved parts of spent rockets or small satellites.
As of Wednesday, there were 9,831 pieces of manmade debris - not counting anything from Tuesday's collision -orbiting Earth. The items, at least 4 inches (10 centimeters) in size, are being tracked by the US Space Surveillance Network, which is operated by the military. The network detected the two debris clouds created Tuesday.
Litter in orbit has increased in recent years, in part because of the deliberate breakups of old satellites. It's gotten so bad that orbital debris is now the biggest threat to a space shuttle in flight, surpassing the dangers of liftoff and return to Earth. NASA is in regular touch with the Space Surveillance Network, to keep the space station a safe distance from any encroaching objects, and shuttles, too, when they're flying.
"The collisions are going to be becoming more and more important in the coming decades," Matney said.
NASA said it will take weeks to determine the full magnitude of the crash, which occurred nearly 500 miles (805 kilometers) over Siberia on Tuesday.
"We knew this was going to happen eventually," said Mark Matney, an orbital debris scientist at Johnson Space Center in Houston.
NASA believes any risk to the space station and its three astronauts should be low. It orbits about 270 miles (435 kilometers) below the collision course. There also should be no danger to the space shuttle set to launch with seven astronauts on Feb. 22, officials said, but that will be re-evaluated in the coming days.
The collision involved an Iridium commercial satellite, which was launched in 1997, and a Russian satellite launched in 1993 and believed to be nonfunctioning. The Russian satellite was out of control, Matney said.
The Iridium craft weighed 1,235 pounds (560 kilograms), and the Russian craft nearly a ton.
No one has any idea yet how many pieces were generated or how big they might be.
"Right now, they're definitely counting dozens," Matney said. "I would suspect that they'll be counting hundreds when the counting is done."
As for pieces the size of micrometers, the count will likely be in the thousands, he added.
There have been four other cases in which space objects have collided accidentally in orbit, NASA said. But those were considered minor and involved parts of spent rockets or small satellites.
As of Wednesday, there were 9,831 pieces of manmade debris - not counting anything from Tuesday's collision -orbiting Earth. The items, at least 4 inches (10 centimeters) in size, are being tracked by the US Space Surveillance Network, which is operated by the military. The network detected the two debris clouds created Tuesday.
Litter in orbit has increased in recent years, in part because of the deliberate breakups of old satellites. It's gotten so bad that orbital debris is now the biggest threat to a space shuttle in flight, surpassing the dangers of liftoff and return to Earth. NASA is in regular touch with the Space Surveillance Network, to keep the space station a safe distance from any encroaching objects, and shuttles, too, when they're flying.
"The collisions are going to be becoming more and more important in the coming decades," Matney said.
Article Source:http://timesofindia.indiatimes.com/World/Satellites-collide-over-Siberia-/articleshow/4115641.cms
0 comments:
Post a Comment