Space 'harpoon' tested in search for answer to junk in orbit
With tens of thousands of pieces of "space junk" in orbit, officials and experts from the world's space agencies are meeting to discuss how to clean it up.
The risk is that old spacecraft - dead satellites and used-up rockets - could collide with satellites needed for navigation, communications and weather forecasting.
One idea being investigated is a "harpoon" to capture the junk and send it down through the atmosphere to burn up.
The BBC's science editor David Shukman was given exclusive access to the first tests, at the labs of the satellite company Astrium in Stevenage.