Artist’s impression of the Fregat separation.
The Sentinel-1B satellite will be launched in a Soyuz rocket on 22 April at 21:02 GMT (23:02 CEST).
Sentinel-1B will join its identical twin, Sentinel-1A, which was launched on 3rd April 2014.
By orbiting 180° apart, global coverage and data delivery are optimised for the Copernicus services.
The mission is being used for a multitude of applications to improve everyday life and understand our changing planet, from tracking land subsidence to monitoring ice in polar oceans.