The Sentinel-6B spacecraft reached NASA’s facility at Vandenberg Space Force Base on 18 August after a trans-Atlantic voyage by cargo ship and a road journey across the United States from Texas. Engineers from NASA, the European Space Agency (ESA), and Airbus ESA’s prime contractor will now begin final launch preparations.
Scheduled to lift-off no earlier than November aboard a SpaceX Falcon 9 rocket, Sentinel-6B will provide critical sea surface height measurements. These data will inform coastal planning, help governments protect infrastructure and energy assets, and improve forecasts vital for shipping, recreation and military operations.
The mission forms part of the joint Sentinel-6/Jason-CS program, an international collaboration between NASA, the European Union, ESA, EUMETSAT, and the US National Oceanic and Atmospheric Administration. Funding has also been provided by the European Commission, with France’s space agency CNES contributing technical expertise.
Sentinel-6B is the second of two satellites in the program, following the launch of its twin, Sentinel-6 Michael Freilich, from Vandenberg in November 2020. Together, they continue a series of US–European missions that have tracked global sea levels since 1992.
After its twin entered service, Sentinel-6B underwent final integration work before being placed into storage until late 2024, when it was removed for testing in Germany. Engineers checked the spacecraft’s systems before loading it into a climate-controlled container for transport to the United States, beginning its journey on 22 July.
NASA’s Jet Propulsion Laboratory is supplying three of the mission’s key science instruments: the Advanced Microwave Radiometer, the Global Navigation Satellite System – Radio Occultation, and the Laser Retroreflector Array.
NASA is also providing launch services, data processing for its instruments and ground support for operations while continuing to back the international ocean surface topography community.
Once operational, Sentinel-6B will replace Sentinel-6 Michael Freilich in monitoring the world’s oceans, ensuring continuity in the long-running data record that underpins climate research and supports practical decision making on Earth.