More than half a million pieces of space junk — spent rocket stages, broken satellites, and even tools dropped by space-walking astronauts — whiz around the Earth at about 17,500 mph, according to NASA. The space agency tracks 16,000 of the larger pieces of junk, those more than 4 in. across. Space junk traveling at more than 25,000 fps poses a considerable threat to operational satellites, spacecraft, and astronauts. Three years ago, for example, an inactive Russian satellite, Cosmos-2251, slammed into a $55 million Iridium satellite, destroying it and putting 2,000 more pieces of space junk into orbit.
To get some of the stuff out of the way, researchers at the Swiss Space Center, part of the Swiss Federal Institute for Technology (EFPL) in Lausanne, are developing technologies for building a spacecraft capable of capturing orbiting debris and taking it down through the Earth’s atmosphere where it, and the high-tech janitor, will burn up.
The initial target will be either the Swisscube, a 10-cm cube that weighs about 2.2 lb and was put into orbit in 2009 for a one-year mission, or Tisat, another 10-cm cube launched in 2010 for the Swiss that has outlived its mission.
Once the new spacecraft, CleanSpace One, is in orbit, technicians will adjust its trajectory to match that of the target satellite. It must also get close enough to the target to latch on to it and possibly stow it inside. This task could be complicated if the target is tumbling. Then CleanSpace will deorbit itself, head back into Earth’s atmosphere and burn up.
EFPL researchers hope to develop a family of ready-made, inexpensive satellites that can collect and get rid of a variety of different types and sizes of satellites. They estimate the first one will cost about $11 million.