Like Sentinel-1, Sentinel-3 is a constellation of two satellites which form part of the Copernicus programme, designed to provide accurate, timely and easily accessible information on the environment.  Sentinel-3 is primarily an ocean mission, however, it also has atmospheric and land applications.

Sentinel-3A, launched in February 2016, is carrying a suite of cutting-edge instruments which allow it to systematically measure the Earth’s oceans, land, ice and atmosphere, and provide essential information in near-real time for ocean and weather forecasting.  As well as measuring the temperature, colour and height of the sea surface, Sentinel-3 will for example measure sea ice thickness and also provide enhanced continuity of satellites such as Envisat and SPOT.

Sentinel-3B will follow 3A into orbit in 2017.