Copernicus Sentinel-6 separates from the Falcon 9 rocket’s second stage about 58 minutes after liftoff. About 10 minutes later, the satellite’s two deployable solar panels open. The satellite’s other solar panels are in a fixed position. Sentinel-6 Michael Freilich launches on 21 November 2020 from the Space Launch Complex 4 East at the Vandenberg Air Force Base near the city of Lompoc in California, US. The Copernicus Sentinel-6 mission comprises two identical satellites launched five years apart – first Sentinel-6 Michael Freilich and then Sentinel-6B in 2025.

The mission takes the role of radar altimetry reference mission, continuing the long-term record of measurements of sea-surface height started in 1992 by the French–US Topex Poseidon and then the Jason series of satellite missions. With sea-level rise one of the biggest threats we face as a consequence of climate change, accurately monitoring the changing height of the sea surface over decades is essential for climate science, for policy-making and, ultimately, for protecting the lives of those in vulnerable low-lying areas.