A four-armed robotic junk collector will be launched into space by the European Space Agency in what it says will be the first mission to remove an item of debris from orbit. About 3,500 defunct satellites and an estimated 750,000 smaller fragments are orbiting the Earth at an average speed of 20,000km/h. Unless a clear-up operation is mounted, the chances of collisions will escalate as thousands more satellites are put into orbit.
The ClearSpace-1 mission, scheduled for launch in 2025, will cost €120m and will grab a single piece of junk. But the agency hopes the mission will pave the way for a wide-reaching clear-up operation, with Esa’s director general calling for new rules that would compel those who launch satellites to take responsibility for removing them from orbit once they are retired from use. “Imagine how dangerous sailing the high seas would be if all the ships ever lost in history were still drifting on top of the water,” said Jan Wörner, Esa’s director general. “That is the current situation in orbit, and it cannot be allowed to continue.”
The target for ClearSpace-1 is a piece of junk called Vespa, which was left in an orbit around 800km above the Earth by ESA’s Vega launcher in 2013. Vespa weighs 100kg – around the size of a small satellite – and was selected because it has a simple shape and sturdy construction, which make it unlikely to fragment when it is grabbed. The “chaser” ClearSpace space probe will be launched into the target orbit where it will track down Vespa, grab it using a quartet of robotic arms and drag it out of orbit, with Vespa and the chaser both burning up in the atmosphere on the way down to Earth. A future ambition is to create a clear-up robot that could eject junk into the atmosphere, before continuing to capture and de-orbit other pieces of junk.
European Space Agency to launch space debris collector in 2025, Guardian, Dec. 9, 2019