A global network of telescopes to monitor space debris, set up in 2004 and coordinated by the Keldysh Institute of Applied Mathematics in Moscow. The network’s main purpose is to identify and track fragments of rockets and satellites that have broken up in orbit around the Earth, but as a by-product it also discovers near-Earth objects and comets; a notable example was the bright sungrazing comet C/2012 S1 (Comet ISON).