A CLOUD of hazardous wreckage is hurtling around the Earth at 25,000mph after the first major traffic crash in space.
Powerful military radars were being used yesterday to monitor at least 600 pieces of debris sent spinning into orbit when two satellites smashed into one another 491 miles above Siberia in Russia.
One was owned by the United States communications
firm, Iridium, which serves commercial customers and the US defence department, and the other was a 16-year-old Russian relay station, Cosmos 2251, that has been out of use for a decade.
The collision between the two is unprecedented in the history of space exploration.
"We believe it's the first time that two satellites have collided in orbit," said Lieutenant Colonel Les Kodlick, of the US Strategic Command.
The crash came to light when the US Space Surveillance Network detected a sudden new cloud of space-junk just as Iridium reported one of its satellites missing.
Nasa, the US space agency, ordered an immediate safety review to establish whether the International Space Station (ISS) – which has a three-man crew on board – might be in danger. A one-millimetre scrap of metal orbiting at 25,000mph can wreak as much damage to the ISS as a speeding bullet, while a piece the size of a tennis ball would be 25 times more powerful than a stick of dynamite.
Experts at Nasa's Johnson Space Centre in Houston, Texas, which has a whole department dedicated to monitoring some 18,000 items of space-junk, said the ISS was not at imminent risk, as it travelled about 280 miles lower than the smashed satellites' orbit.
Over time, however, the wreckage will cascade downwards – ultimately dropping out of orbit and burning up in Earth's atmosphere – and could yet force Nasa to shift the ISS's position to avoid another accident.
The space station has had to take evasive action eight times in the past, firing thrusters to move itself out of the path of space litter such as disused rockets, fuel tanks and satellites, or nuts and bolts from broken-down spacecraft. Even a spanner dropped during a spacewalk by the British astronaut Piers Sellers in 2006 had to be tracked by military radar to ensure it had drifted safely out of range.
There is also concern for the safety of scores of other satellites – both military and civilian – that operate at the same altitude as the collision site, and for the Hubble Space Telescope, which travels 360 miles above the Earth and has given scientists unparalleled glimpses of the universe for the past 18 years.
Nasa will continue to track the fall-out to pinpoint its path. "It takes a while for the debris to spread out and for us to get an accurate head count," one of its scientists said.
The collision was the worst space debris event since the Chinese blew up one of their satellites during a controversial missile test in 2007, littering orbit with about 2,500 pieces of shrapnel in a cloud 2,000 miles deep, and triggering an international political outcry.
Officials said neither satellite involved in Wednesday night's crash was to blame – there is no right of way in space, and no air traffic controllers.
Iridium said its crash satellite was one of 66 it had in orbit. It is to programme one of its "spares" to take its place.
Royal Air Force keeps watch on clouds of crash debris from radar stationA BRITISH radar station was yesterday tracking the debris clouds formed by the collision of the two satellites.
Operators at the tracking station at RAF Fylingdales, high on the North Yorkshire Moors, were attempting to assess the risk posed by the pieces of wreckage from the crash. The Fylingdales base forms part of a worldwide network of powerful radars and tracks all objects in orbit bigger than 10cm as well as providing early warning of any incoming ballistic missile attack.
A spokesman for RAF Fylingdales said: "Analysis of the radar data and information from the Space Surveillance Network confirmed the objects to be 'clouds of debris' from the two satellites.
"Work is now under way to identify how many items of debris have been generated by the collision, calculate if any of that debris is liable to come into contact with the manned International Space Station, and monitor any of the debris that may fall back to earth.
"This new debris is liable to be orbiting the earth for weeks if not months to come."
Nasa believes any risk to the International Space Station and its three astronauts should be low as it orbits about 270 miles below the collision course.
Dr Jill Stuart, from the London School of Economics, said the collision threw up interesting questions for "outer space lawyers" who will now have to sort out who will pay damages for the collision.
According to some reports, those managing the current Russian space programme have distanced themselves from liability saying the old satellite was launched by a previous Russian agency.
The full article contains 851 words and appears in The Scotsman newspaper.
