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Russian, American satellites collide

— Photo: AFP

Dangerous trajectory: A computer-generated artist’s impression released by the European Space Agency (ESA) depicts an approximate 12,000 objects in orbit around the Earth.

CAPE CANAVERAL (Florida): Scientists are keeping a close eye on orbital debris created when two communications satellites — one American, the other Russian — smashed into each other hundreds of km above the Earth.

NASA said it would take weeks to determine the full magnitude of the unprecedented crash and threat if any to other satellites or even the Hubble Space Telescope.

The collision, which occurred nearly 800 km. over Siberia on Tuesday, was the first high-speed impact between two intact spacecraft, said NASA officials.

“We knew this was going to happen eventually,” said Mark Matney, an orbital debris scientist at Johnson Space Centre in Houston.

NASA believes any risk to the International Space Station and its three astronauts is low. It orbits about 435 km. below the collision course.

A spokesman for the Russian civilian space agency Roscosmos, Alexander Vorobyev, said on state-controlled Channel I television that “for the International Space Station, at this time and in the near future, there’s no threat”.

There should be no danger to the space shuttle set to launch with seven astronauts on February 22, officials said, but that will be re-evaluated in the coming days.

Nicholas Johnson, an orbital debris expert at the Houston space centre, said the risk of damage from Tuesday’s collision was greater for the Hubble Space Telescope and Earth-observing satellites, which were in higher orbit and nearer the debris field.

The collision involved an Iridium commercial satellite, which was launched in 1997, and a Russian satellite launched in 1993 and believed to be non-functioning. The Russian satellite was out of control, said Mr. Matney.

The Iridium craft weighed 560 kg., and the Russian craft nearly a tonne.

No one has any idea yet how many pieces were generated or how big they might be.

“Right now, they’re definitely counting dozens,” said Mr. Matney. “I would suspect that they’ll be counting hundreds when the counting is done.”

There had been four other cases in which space objects had collided accidentally in orbit, NASA said. But those were considered minor and involved parts of spent rockets or small satellites.

At the beginning of this year there were roughly 17,000 pieces of manmade debris orbiting Earth, Mr. Johnson said.

The items, at least 10 cm. in size, are being tracked by the U.S. Space Surveillance Network, which is operated by the military. The network detected the two debris clouds created on Tuesday.

Litter in orbit has increased in recent years, in part because of the deliberate breaking up of old satellites. It has gotten so bad that orbital debris is now the biggest threat to a space shuttle in flight, surpassing the dangers of lift off and return to Earth. “The collisions are going to be becoming more and more important in the coming decades,” said Mr. Matney. — AP

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