Thales Alenia Space Technologies Enable Successful Deployment of Sentinel-6B to Track Rising Oceans

Sentinel-6B © ESA

(IN BRIEF) The Copernicus Sentinel-6B satellite has been successfully launched from Vandenberg Space Force Base aboard a SpaceX Falcon 9, marking a major milestone in global sea-level monitoring. Developed through a partnership between the European Commission, ESA, Eumetsat, NASA, NOAA, and CNES, the mission ensures continuity of high-precision radar altimetry data through at least 2030. Built by Airbus and equipped with Thales Alenia Space’s Poseidon-4 altimeter, Sentinel-6B will operate alongside its twin satellite for one year before assuming primary responsibility for observing ocean topography with sub-centimeter accuracy. With sea levels currently rising at 3.3 mm annually and coastal populations increasingly at risk, the mission provides critical data to support climate adaptation, emergency planning, and scientific research. Thales Alenia Space, a key contributor to 11 Copernicus missions and a global leader in radar altimetry technology, continues its decades-long role in advancing operational oceanography and Earth-observation capabilities.

(PRESS RELEASE) VANDENBERG CA, United States, 17-Nov-2025 — /EuropaWire/ — The latest chapter in Europe’s climate-monitoring efforts has begun with the successful launch of the Copernicus Sentinel-6B satellite from Vandenberg Space Force Base in California aboard a SpaceX Falcon 9 rocket. Designed to deliver precision radar measurements of sea level and ocean conditions, Sentinel-6B will operate at the heart of a multi-agency programme that includes the European Commission, ESA, Eumetsat, NASA, NOAA, and CNES. Thales Alenia Space, a long-standing partner in global altimetry missions, supplied the spacecraft’s key technologies: the Poseidon-4 radar altimeter and S-band TT&C transponders, both built to provide ultra-precise, long-term sea level data essential for climate science and coastal safety.

For the next year, Sentinel-6B will fly in parallel with its twin, Sentinel-6 Michael Freilich, to ensure mission continuity before taking over full operational duties until at least 2030. The data it gathers will play a vital role in tracking accelerating sea level rise—a major consequence of global warming that threatens the nearly 10% of the world’s population living less than 10 metres above sea level. Current measurements show oceans rising at an average of 3.3 mm per year, a pace that has increased over recent decades.

The Poseidon-4 altimeter at the core of Sentinel-6B provides sub-centimetre measurement accuracy, enabling scientists to monitor ocean surface topography every 10 days. These readings are critical for understanding climate dynamics, wave and current behaviour, and extreme weather risks. High-resolution sea-level monitoring also supports early-warning services for emergency responders, city planners, and infrastructure authorities protecting coastal communities.

Hervé Derrey, President and CEO of Thales Alenia Space, welcomed the successful deployment of Sentinel-6B, noting that the mission represents continuity of a decades-long international collaboration in operational oceanography. “This launch secures the next era of high-precision sea-level data, ensuring governments and climate scientists have reliable information to protect vulnerable populations,” he stated.

Weighing approximately 1.2 tonnes, Sentinel-6B will operate in low Earth orbit at 1,336 kilometres, with a projected mission life of seven years. Its deployment reinforces Thales Alenia Space’s prominent role in the Copernicus programme: the company contributes to 11 out of 12 missions across the constellation, including prime contractor leadership for Sentinel-1 and Sentinel-3. In addition to providing the Poseidon altimeters used for decades across the Jason and SWOT missions, Thales Alenia Space has also delivered world-leading instruments such as SIRAL-2 for CryoSat-2 and the AltiKa system for the Franco-Indian SARAL satellite.

The company’s Toulouse facility has become the global benchmark for satellite altimetry engineering—building a lineage of instruments that enabled the very first centimeter-level ocean measurements beginning with TOPEX/Poseidon in the 1990s. Successive missions, including Jason-1, Jason-2, Jason-3, and SWOT, have since expanded the science of sea-surface monitoring, delivering detailed measurements of lakes, rivers, ocean currents, and polar ice dynamics.

With Sentinel-6B now in orbit, the world’s leading space agencies and climate institutions will continue to receive uninterrupted, ultra-precise data to inform policy, strengthen coastal resilience, and deepen global scientific understanding of climate change.

The birth of satellite altimetry and programs in partnership with CNES

The feasibility of acquiring precise and continuous measurements of ocean surface topography from space was first explored by the U.S. Geosat and Seasat missions. NASA and CNES subsequently joined forces to develop and further satellite altimetry, giving rise to the TOPEX/Poseidon mission, with the very ambitious aim of acquiring global coverage of the oceans with centimeter accuracy. The first Poseidon altimeter was the culmination of a seven-year joint effort on the part of CNES and Thales Alenia Space’s teams in Toulouse. The TOPEX/Poseidon satellite began its mission in 1992 and was immediately successful, paving the way for a 30-year partnership between CNES and NASA. Thales Alenia Space has been integral to these outstanding programs from the outset, in particular building the radar altimeter instruments for all subsequent missions: Jason 1 (carrying the Poseidon-2 altimeter), Jason-2 (Poseidon-3A), Jason-3 (Poseidon-3B) and more recently SWOT (Poseidon-3C and a wide-swath altimeter).

About Thales Alenia Space

Drawing on over 40 years of experience and a unique combination of skills, expertise and cultures, Thales Alenia Space delivers cost-effective solutions for telecommunications, navigation, Earth observation, environmental monitoring, exploration, science and orbital infrastructures. Governments and private industry alike count on Thales Alenia Space to design satellite-based systems that provide anytime, anywhere connections and positioning, monitor our planet, enhance management of its resources and explore our Solar System and beyond. Thales Alenia Space sees space as a new horizon, helping build a better, more sustainable life on Earth. A joint venture between Thales (67%) and Leonardo (33%), Thales Alenia Space also teams up with Telespazio to form the Space Alliance, which offers a complete range of solutions including services. Thales Alenia Space posted consolidated revenues of €2.23 billion in 2024 and has more than 8,100 employees in 7 countries with 14 sites in Europe.

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SOURCE: Thales