EU/US: Sentinel- 6B satellite in orbit to monitor sea-level rise

The Sentinel-6B satellite of the Copernicus programme has been placed in orbit on 17/11/2025, announced the European Commission and ESA (European Space Agency).

Sentinel-6B is a joint EU-US mission to extend the precise record of global sea levels: it succeeds Sentinel-6 Michael Freilich, which had been launched in November 2020. Like its predecessor, it is equipped with a highly accurate radar altimeter that can measure ocean height with in a 1-centimeter accuracy.

Since the 1990s, the average sea level has risen by more than 8 cm, according to satellite and model data, including those provided by the Copernicus service. The rate of rise has accelerated from around 2.9 mm/year between 1999 and 2009 to 4.2 mm/year between 2014 and 2024.

Sea level measurement is a major indicator of climate change, helping scientists understand sea-level rise and shaping climate policy. The collected data will support governments and coastal communities in preparing for flooding, erosion, and increasingly frequent extreme weather events.

As well as mapping the height of the sea surface to understand…