The Sentinel-3B launch campaign team in Plesetsk, Russia, is ready for liftoff. This latest Copernicus satellite is scheduled to be launched on 25 April at 17:57 GMT (19:57 CEST). Its identical twin, Sentinel-3A, has been in orbit since February 2016. The two-satellite constellation offers optimum global coverage and data delivery for Europe’s Copernicus environment programme.