Crash of U.S., Russian satellites a threat in space

MOSCOW -- The collision between U.S. and Russian communication satellites this week — the first such crash in space — has created speeding clouds of debris that threaten other unmanned spacecraft in nearby orbits, Russian officials and experts said Thursday.

The smashup 500 miles (800 kilometers) over Siberia on Tuesday involved a derelict Russian spacecraft designed for military communications and a working U.S. Iridium satellite, which serves commercial customers as well as the U.S. Department of Defense.

In a statement Thursday, Iridium, based in Bethesda, Maryland, denied that it was responsible for the crash. The collision scattered space debris in orbits 300 to 800 miles (500 to 1,300 kilometers) above Earth, according to Maj.-Gen. Alexander Yakushin, chief of staff for the Russian military's Space Forces.

But Igor Lisov, a prominent Russian space expert, said Thursday he did not understand why NASA's debris experts and Iridium had failed to prevent the collision, since the Iridium satellite was active and its orbit could be adjusted.

"It could have been a computer failure or a human error," he said. "It also could be that they only were paying attention to smaller debris and ignoring the defunct satellites."

Lisov said the debris may threaten a large number of earth-tracking and weather satellites in similar orbits.

"There is a quite a lot of satellites in nearby orbits," he told The Associated Press. "The other 65 Iridium satellites in similar orbits will face the most serious risk, and there numerous earth-tracking and weather satellites in nearby orbits. Fragments may trigger a chain of collisions."

Both the U.S. Space Surveillance Network and Russian Space Forces are tracking the debris, believed to be traveling at speeds of around 200 meters — or about 660 feet — per second.

NASA said it would take weeks to know the full magnitude of the crash, but both NASA and Russia's Roscosmos agencies said there was little risk to the international space station and its three crewmembers.