Last Friday, Japan’s space agency lauched Kounotori (“White Stork”), a space capsule that will attempt to clean space debris orbiting around earth, using an unusual approach. Orbital debris, which consists of man-made objects, is usually the residue of inactive space vehicles. Because these objects move at high speeds and can collide with incoming space vehicles, there’s a case for cleaning them out. The experiment is part of an international initiative designed to make space safer for astronauts by getting rid of space junk. It is hoped that it will also provide better protection for space stations and weather and communications satellites worth billions of dollars.
The Kounotori uses a kind of “electrodynamic tether” forged from thin wires of stainless steel and aluminium. One end of the strip will be attached to debris and the electricity generated by the tether as it swings through the earth’s magnetic field. It is expected to slow the speed of space junk and pull it into a lower and lower orbits.
Eventually the detritus will enter the earth’s atmosphere, burning up harmlessly long before it has a chance to crash to the planet’s surface.