International space station veers to avoid space junk

The ISS will move to a new orbit Thursday to avoid a possible collision with a fragment of debris. Over 21,000 pieces of space junk larger than a softball are estimated to be circling the planet.

The Russian space program's Mission Control Center says it will move the International Space Station into a different orbit to avoid possible collision with a fragment of debris.

Mission Control Center spokeswoman Nadyezhda Zavyalova said the Russian Zvevda module will fire booster rockets to carry out the operation Thursday at 07:22 a.m. Moscow time (0322 GMT).

The space station performs evasive maneuvers when the likelihood of a collision exceeds one in 10,000.

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NASA estimates that more than 21,000 fragments of orbital debris larger than a softball 10 centimeters (3.9 inches) are stuck in earth's orbit, and experts worry that orbiting junk is becoming a growing problem for the space industry.

As Space.com notes: "Inactive satellites, the upper stages of launch vehicles, discarded bits left over from separation, and even frozen clouds of water and tiny flecks of paint all remain in orbit high above Earth's atmosphere. When one piece collides with another, even more debris is released. Over 21,000 pieces of space trash larger than 4 inches (10 centimeters) and  half a million bits of junk between 1 cm and 10 cm are estimated to circle the planet. And the number is only predicted to go up."

NASA says that the speed at which this detritus travels creates the risk. The debris travels at speeds up to 17,500 mph, "fast enough for a relatively small piece of orbital debris to damage a satellite or a spacecraft. There are 500,000 pieces of debris the size of a marble or larger. There are many millions of pieces of debris that are so small they can’t be tracked. Even tiny paint flecks can damage a spacecraft when traveling at these velocities. In fact a number of space shuttle windows have been replaced because of damage caused by material that was analyzed and shown to be paint flecks.
 “The greatest risk to space missions comes from non-trackable debris,” said Nicholas Johnson, NASA chief scientist for orbital debris.

There are six astronauts — three Russians, two Americans and one from Japan — onboard the orbiting laboratory.

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Copyright 2012 The Associated Press.