Harpoon that targets ‘space junk’

BRITISH engineers have created a space harpoon that could help capture rogue satellites and pull them back down to earth.

The 3ft missile would be fired from a ‘hunter-killer’ spacecraft, which would pull it – and its prey – back using a cord.

Aviation giant Airbus said the harpoon is being tested at its space research centre in Stevenage.

There are more than 20,000 pieces of ‘space junk’ – at least the size of a cricket ball – floating above the earth.

These can damage existing satellites and manned spacecraft such as the International Space Station. The harpoon would be deployed against only those that pose the greatest risk.

Its top target is a defunct weather satellite, Envisat, which weighs eight tons and stopped working in 2012.

Alastair Wayman, an Airbus engineer, told the BBC: ‘The harpoon is propelled by using compressed air. In tests it has pierced aluminium panels that are similar to those used in satellites… the harpoon goes through these panels like a hot knife through butter.

‘Once the tip is inside, it has a set of barbs that open up and stop the harpoon from coming back out.

‘This is where harpoons should come into their own, over other methods of capture such as nets and robotic arms. A harpoon is relatively simple. You line up the target and shoot.’

The European Space Agency, responsible for Envisat, is considering other ways of bringing the satellite to earth.

Airbus will launch a miniature version of the harpoon next month for testing.

The Stevenage team are currently working on getting the harpoon to fire over a distance of 82ft – the sort of distance it will have to travel in space.