Space junk is a very major problem and if not tackled soon, there will be more than 20,000 useless objects in space rotating around us. This includes de-functional satellites and paint chips. Their number can increase so much that we might be unable to approach the outer space at all one day. The scientists have started working on this case already. In the UK, a team at Airbus has started developing a very lo-fi method to remove the large pieces of junk from the orbit. They have developed a giant harpoon.
The harpoon is almost a meter long and will be attached to a spacecraft using a strong tether. It will allow the junk to be attached to the harpoon and follow it to the earth. The junk will then be burned on earth. To test it, the researchers have been shooting the harpoon in the lab using compressed air. The harpoon has been shot at 3-cm think aluminium composite honeycomb panels. The advance project engineer Alastair Waymann said, “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. We’d then de-tumble the satellite with a tether on the other end.”
Wayman added, “Many of these targets will be tumbling and if you were to use a robotic arm, say, that involves a lot of quite complex motions to follow your target. Whereas, with the harpoon, all you have to do is sit a distance away, wait for the target to rotate underneath you, and at the right moment fire your harpoon. And because it’s a really quick event, it takes out a lot of the complexity.” The biggest piece of junk out there is the Envisat Earth observation satellite. It is an eight-ton of metal which has been floating uselessly for almost six years.
Wayman told, “If we can design a harpoon that can cope with Envisat, then it should be able to cope with all other types of spacecraft including the many rocket upper-stages that remain in orbit.” Airbus harpoon will be put to test very soon. A miniature version of the device will be sent to space in the coming month with a mission launched by RemoveDebris. This mission will release their own piece of junk and then capture it by using a net and a harpoon both.