US, Russian satellites collide in space

HIGH-SPEED prangs are not confined to the road. They also happen far above our heads.

In a space-age first, two satellites have collided in orbit. Early on Wednesday morning, Sydney time, a Russian communications satellite and an American Iridium mobile phone spacecraft smashed into each other, 790 kilometres above Siberia.

The cosmic bingle left both write-offs. US Air Force Brigadier General Michael Carey, of US Strategic Command, said at least 600 pieces of wreckage had been observed circling the world.

"We knew this was going to happen eventually," said Mark Matney, of NASA's Orbital Debris Program Office.

The Spaceflightnow.com website quoted the program's chief scientist, Nicholas Johnson, saying no one was to blame. The satellites just "ran into each other".

"Nothing has the right of way up there," he said. "We don't have an air-traffic controller in space."

But Ben Greene, chief executive of Electro Optic Systems (EOS), an Australian high-technology company, said yesterday his research team had developed a laser system for cosmic traffic control.

"Four years ago, we predicted [a collision] of this nature would happen within five years," Dr Greene said. The satellites, both travelling at more than seven kilometres a second, would have hit at almost right angles. "It would have been a massive prang," he said.

Orbital traffic control had been impossible because the position of most satellites, until now, could only be plotted to an accuracy of four of five kilometres.

His laser system, developed at a cost of $50 million with help from the Federal Government and satellite operators, could track objects with an accuracy of a few metres and warn satellite operators when to change course.

Dr Greene said the 3500 operational satellites in orbit were worth "well over $1 trillion". His company provided laser tracking data to satellite operators "on a demonstration basis".

Yesterday, NASA was trying to determine whether the wreckage posed a danger to other satellites. Initial findings showed the risk to the International Space Station was "very, very small".

The 900 kilogram Russian satellite, Cosmos 2251, was launched in 1991 and ended its working life 10 years ago. The 670 kilogram American vehicle was one of 66 operational Iridium spacecraft relaying satellite-telephone communications.

NASA says about 17,000 objects bigger than 10 centimetres, mostly debris from satellites and rockets, circle Earth.