If you have a feeling of deja vu at the Sentinel-3B above don’t worry this is a twin. The first was launched in 2016 and this one is scheduled to be launched on 25 April 2018.
This great image is from ESA – S. Corvaja.
ESA’s caption — The Copernicus Sentinel-3B satellite being mated with the Rockot adapter at the Plesetsk Cosmodrome in northern Russia.
The satellite is being prepared for liftoff, scheduled for 25 April 2018. 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.