But two events in the past four years - a 2007 Chinese anti-satellite weapon test and a 2009 crash-in-orbit of two satellites - put so much new junk in space that everything changed, the report said.

Yet the destruction of the Chinese Fengyun-1C in an anti-satellite missile test in 2007 accounts for more than a quarter of all catalogued objects in low-Earth orbit.

Satellite on-orbit test is a useful way to monitor satellite platform, on-orbit status and attenuation degree of sensors, and is the premise and base for satellite data's processing and application.