Is it a bird? Is it a plane? No, it's space debris.

This legacy of junk - the remains of now-defunct satellites and space launches - is becoming a serious threat to the safety of modern satellites, presenting a growing risk of collision and damage.

The financial sums involved are astronomical. There are around 180 insured satellites currently in orbit with a total value of $22bn, with more than a third insured through the London market.

A recent report from insurer Allianz highlights the space-debris problem and emphasises the need to develop technologies to clean up the packed area of space nearest the Earth.

“Since the beginning of the space story, the amount of debris orbiting the Earth has grown and it’s now very high,” says Ludovic Arnoux, Aviation and Space Underwriter at Allianz Global Corporate & Speciality.

In 2010, more than 16,000 pieces of debris measuring more than 10cm across were catalogued in low earth orbit, but there are millions more too small to track, and that figure is multiplying all the time as larger pieces collide and fragment.

Travelling at speeds of 10km/s, even a relatively small piece of debris can cause significant damage to large satellites, depending on its size and trajectory. A larger piece could result in a total loss. The first collision between two intact satellites occurred in February 2009 when Russia’s out-of-service Kosmos 2251 smashed into Iridium 33, an operational American satellite. The collision destroyed both satellites and created more than 2000 new pieces of space debris.

Insurers currently demand that satellites in lower orbits demonstrate certain operational procedures to mitigate the risk of collision. Following another major incident, these could become tougher still, says Arnoux.

It is now standard practice to deorbit old satellites at the end of their mission, but there is as yet no practical, cost-effective way of clearing older debris still in orbit. Possible solutions involve using lasers to destroy the rubbish, or docking satellites to force them to re-enter the Earth’s atmosphere where they will burn up, though no method is sufficiently developed as yet.

For now, space debris remains an area of major uncertainty for underwriters in a field that is already full of high-level risk. Back at Allianz, space underwriter Arnoux is keeping a watchful eye on the night skies:

“For now, the risk is still acceptable, but we must pay attention because we know that if nothing is done, it could become catastrophic.”

Read the full report by Allianz: Space Risks: A new generation of challenges 

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