Space junk could be tackled by housekeeping spacecraft

BBC : More than 17 000 objects of a size greater than 10 centimeters currently reside in low Earth orbit. Created by humans, they consist of spent rocket stages, defunct satellites, and fragments from explosions and collisions. About 40 of the pieces are very large, weighing in at more than three tons each. Space junk is potentially hazardous to operational spacecraft, including the International Space Station. And each large piece of debris could create thousands of smaller ones if it breaks up. China’s 2007 anti-satellite demonstration broke up one of that country’s defunct satellites into about 2000 pieces. Such an event can start a chain reaction, in which fragments hit other fragments, which break apart, creating even more, until large areas of low Earth orbit become unusable. To clean up the mess, Marco Castronuovo of the Italian Space Agency proposes that a satellite could be launched to rendezvous with large orbiting debris and attach a propellant kit that would then drive the object into Earth’s atmosphere where it would burn up. He estimates that between 5 and 10 large objects could be removed from orbit this way every year.