London: The amount of space junk orbiting the Earth is at tipping point and could cause severe damage to spaceships and satellites, a new report has warned.

The report by the US National Research Council said the debris, which includes clouds of minuscule fragments, old boosters and defunct satellites, could cause fatal leaks in spaceships or destroys valuable satellites.

It called for international regulations to limit the junk and more research into the possible use of launching large magnetic nets or giant umbrellas, an agency reported.

Computer models show the amount of orbital rubbish "has reached a tipping point, with enough currently in orbit to continually collide and create even more debris, raising the risk of spacecraft failures," said the report.

Hopes of limiting the amount of space junk in orbit suffered two major setbacks in recent years.

In 2007, China conducted an anti-satellite weapon test which destroyed a decommissioned weather satellite, smashing the object into 150,000 pieces larger than 1cm.

Two years later, two satellites -- one defunct and one active -- crashed in orbit, creating even more debris.
"Those two single events doubled the amount of fragments in Earth orbit and completely wiped out what we had done in the last 25 years," said Donald Kessler, who led the research.

There are 22,000 pieces of debris large enough to track from the ground, but smaller objects could still cause serious damage.

The International Space Station must occasionally dodge some of the junk, which flies around the Earth at speeds of up to 28,164 kmph, the researchers said. In June, some debris narrowly missed the space station, forcing its six crew to go to their escape capsules and prepare for an emergency evacuation back to Earth.

The situation is critical, said Kessler, a retired NASA scientist, because colliding debris creates even more of the junk. "We've lost control of the environment," he said.

The new report makes no recommendations about how to clean up the field of debris, but it refers to an earlier study for the Pentagon's science think-tank, the Defence Advanced Research Projects Agency (Darpa).

The Darpa report, dubbed "Catcher's Mitt", suggested a range of technologies, including harpoons, nets and an umbrella-shaped device that would sweep up the debris.

The aim would be to push the debris further towards the earth where it would burn up, or into a higher but safer orbit, the researchers said.