Satellite constellation

Depending on the instrument, the Sentinel-3 satellites provide global coverage every two days. The majority of the data are processed systematically and available for users within 3–48 hours after sensing.

The satellites were developed by a consortium of companies led by Thales Alenia Space in France. The design of the satellite and instruments builds on heritage missions such as ESA’s ERS, Envisat and CryoSat as well as France’s SPOT Vegetation and the series of Jason altimetry satellites.

The mission is the result of close collaboration between ESA, the European Commission, Eumetsat, industry, service providers and data users.

Each satellite is designed for a life of at least seven years and has enough fuel to provide up to 12 years of continuous operations.

ESA and Eumetsat share the responsibility for the smooth running of the mission. After the successful completion of the commissioning phase, encompassing the first five months in orbit testing the functionality of the satellite, ESA hands over the operations of the satellites to Eumetsat.

ESA then continues to monitor the health of the satellites, including platform and instruments.  ESA is responsible for the operations of the Sentinel-3 ground segment for land products as well as the continuous improvement of the data products through research and development activities. Eumetsat is responsible for providing the marine products and operating the satellite.

Together with the rest of the Sentinel fleet, the Sentinel-3 satellites make a unique contribution to the paradigm shift in the quality and quantity of Earth observation measurements over our planet in the coming decades.

Sentinel-3A was launched on 16 February 2016, followed by Sentinel-3B on 25 April 2018. A third satellite, Sentinel-3C, was launched on 15 September 2026 to ensure the continuity of this vital source of knowledge.