November 6, 2015 — Sentinel-3A’s preparation is finished and the satellite will soon be shipped to the Russian Cosmodrome of Plesetsk, in Northern Russia for its launch on top of a Rockot planned end of this year.
Carrying a suite of state-of-the-art instruments, Sentinel-3 is set to play a key role in Copernicus, the world’s largest environmental monitoring programme operated by the European Commission. It will provide highly accurate measurements on Earth’s oceans, land, ice and atmosphere.
http://www.esa.int/esatv/Videos/2015/11/Sentinel-3_mission_overview