Satellite switches off

Envisat, an observation satellite whose data is widely used by environmental researchers, has stopped sending data to Earth, prompting calls for a timely launch of its replacement, the GMES Earth monitoring system. Launched in 2002, Envisat has exceeded its planned five-year life, but the European Space Agency is seeking to re-establish contact with it. Volker Liebig, ESA’s director of Earth observation programmes, said: “The interruption of the Envisat service shows that the launch of the GMES Sentinel satellites has become urgent.”