Space debris likely to be major threat to future space missions: European Space Agency

Chances of mass collisions between man-made satellites and space debris might be 25 times higher soon, researchers at the European Space Agency (ESA) said. They say the amount of debris from man-made objects was about to reach "criticality".

To address the problem, the space agency was now designing a hunter-killer space probe that would track down and destroy defunct satellites.

The e.DeOrbit probe would deploy a Roman gladiator-style array of nets and harpoons for trapping the first rogue satellites, dragging them downwards until they burnt up in the atmosphere. Several capture mechanisms were under study, including throw-nets, clamping mechanisms and harpoons, according to the ESA.

A symposium to be held in the Netherlands in May would cover studies and technology developments related to e.DeOrbit.

Space debris had become a major risk to space missions, as even an object of 1 cm could hit a satellite with the energy of a hand-grenade.

In over half a century of space activities, more than 4,800 launches had put some 6,000 satellites into orbit of which less than a 1,000 were still operational today.

According to the ESA, with the increasing debris in orbit around the earth, future space missions could become impossible.

According to the scientists, the swirling space debris could end up making swathes of space inaccessible.

''If the current launch rate continues, then collisions will soon be 25 times higher than now. This would make space flight in low Earth orbits almost impossible,'' ESA said.

''There are already 17,000 trackable objects larger than a coffee cup, which threaten working missions with catastrophic collision. Even a 1cm nut could hit with the force of a hand grenade.''

While the question remained how long it would take for the debris cascade to render space unusable, according to researchers there were already certain orbits, popular with communication and military satellites, that could become unusable within a decade or two.

The worst affected are orbits of 800-965 km altitude that passed over the poles, as these already contained many of the 5,000 or so satellites launched from earth since the space age began.

The ESA said the debris cloud could be held in check by removing between five and 10 large satellites from space each year.