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Soon, a probe to zap piling-up space junk [Science] [Times of India]
[March 18, 2014]

Soon, a probe to zap piling-up space junk [Science] [Times of India]


(Times of India Via Acquire Media NewsEdge) LONDON: Chances of mass collisions between man-made satellites and space debris may soon be 25 times higher, according to researchers at the European Space Agency (ESA) who now believe that that the amount of debris from man-made objects is about to reach "criticality".



To tackle the problem the space agency is designing a hunter-killer space probe to track down and destroy defunct satellites.

The e.DeOrbit probe would deploy a Roman gladiator-style array of nets and harpoons to first trap rogue satellites and then drag them downwards until they burn up in the atmosphere. Several capture mechanisms are being studied including throw-nets, clamping mechanisms and harpoons, the ESA said.


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

Space debris has become a major risk to space missions - a one cm object can expend the energy of a hand-grenade after colliding with a satellite.

In more than half a century of space activities, more than 4800 launches have placed some 6000 satellites into orbit of which less than a 1000 are still operational today.

More than 12000 orbiting items in total are regularly tracked by the US Space Surveillance Network and maintained in their catalogue which covers objects larger than approximately 5 to 10cm in low Earth orbit (LEO) and 30cm to 1m at geostationary altitudes (GEO).

Only 6% of their catalogued orbital population represents operational satellites while 38% can be attributed to decommissioned satellites, spent upper stages and mission-related objects (launch adaptors, lens covers).

The remaining 56% originates from more than 200 in-orbit fragmentations which have been recorded since 1961.

Except for a few collisions (less than 10 accidental and intentional events), the majority of the 200 break-ups were explosions of spacecraft and upper stages - typically due to leftover fuel, material fatigue or pressure increase in batteries.

ESA's Clean Space initiative - tasked with reducing the space industry's environmental impacts on both Earth and space -aims to evaluate battery behaviour after a satellite shuts down, assessing the risk of breakup and ensuring full 'passivation'.

Batteries are among a satellite's bulkier items of equipment. Typically they feed their host with power during launch. Once in orbit it switches to power from its solar arrays but the battery is an important backup to store power for eclipses and emergencies.

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