The amount of debris orbiting the Earth has reached a critical level. Old satellite parts, solar panels and the odd astronaut's lost glove now pose serious risks to space missions. A report from the International Association for the Advancement of Space Safety is calling for stringent international laws to be brought in urgently to avert a tragedy.

The threat posed by orbiting debris can only be allayed by extending civil aviation standards into space, says the report, which is to be presented to the United Nations in April. 'Failure to act now to regulate space to protect property and human life would be pure folly,' says the association's director, Tommaso Sgobba. Professor Richard Crowther, who is representing the UK at a UN space safety meeting in Vienna, agrees: 'Eventually binding international civil aviation style laws will have to come.'

Last week, the United States courted an international row after shooting down a disabled spy satellite, saying its fuel could cause serious damage if it crashed to Earth. Russia, however, claimed that the operation was a US cover-up to test its anti-satellite weapons.

According to the space agency Nasa, there are now 9,000 pieces of orbiting junk, weighing a total of more than 5,500 tonnes: old rocket launchers, tools and instruments dropped by astronauts, and pieces of exploded spacecraft. Examples include a glove lost by astronaut Ed White during a 1965 space walk, a camera that Michael Collins let slip in space in 1966 and a pair of pliers that an International Space Station astronaut recently let slip through their fingers.

Space junk varies in size from tiny bolts and screws to huge lumps of fuselage and are to be found in two main regions: low Earth orbit, a few hundred miles above Earth, and geostationary orbit, 22,300 miles up, where communication satellites are programmed to hover above the planet.

In low Earth orbit, pieces of debris pose particular problems. They could strike manned spacecraft and lead to fatal depressurisation, space experts warn. In 1991, a space shuttle had to carry out an emergency seven-second burn of its engines to avoid being struck by part of a Russian Cosmos satellite.

Low-orbiting debris also poses a risk to Earth itself. In 2006, pieces of a Russian spy satellite burnt up in the atmosphere, passing perilously close to a Latin American Airbus carrying 270 passengers over the Pacific.

To date, only one person has been injured by space debris, however: an Oklahoma woman who was hit in the shoulder by a piece of a Delta rocket's fuel tank, but who was uninjured by this extraterrestrial attack.

The problem, according to the Association for the Advancement of Space Safety report, is that up to 20 countries are now able to launch objects into space - but very few of these have rigid safety protocols. Nor is the problem of space debris confined to near Earth, it adds. Satellites in geostationary orbit are supposed to be moved farther into space after they become defunct - but often that obligation is not met.

More than 200 dead satellites now litter this vital part of space. Within 10 years that number could increase fivefold, warns the report. The resulting chaos could lead to serious damage or loss of a spacecraft.

'Unfortunately we may have to wait for something to happen, perhaps a big near miss, before people realise we can't go on as we are,' Crowther said.