Sentinel-6B being enclosed in its shipping container.
The Sentinel-6B (S-6B) satellite was launched on November 16, 2025, at Vandenberg Space Force Base in California. It is the second satellite of the Sentinel-6 series of spacecraft. This series is part of an international partnership with NOAA, European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), NASA, and the European Space Agency (ESA), with support from the French space agency, Centre National d'Études Spatiales (CNES). The first satellite of the mission was Sentinel-6 Michael Freilich (S-6 MF), also known as Sentinel 6-A (S-6A), which was launched in November 2020.
Sentinel-6B on launch pad.
The S-6B instruments, such as the radar altimeter, will collect observations of oceanography data by bouncing signals off the ocean surface to make fundamental and precise measurements of sea level, wave heights and marine winds. These include measurements of ocean topography (sea surface height), atmospheric water vapor, and global navigation satellite systems (GNSS), which will collect more detailed information about atmospheric temperature and water vapor.
S-6B Ocean Data for Users
NESDIS’s Center for Satellite Applications and Research (STAR) products and tools, like the radar altimeter instrument on S-6B, support operations and forecasts at the National Weather Service’s (NWS) Ocean Prediction Center. Other partners include NOAA’s National Hurricane and Environmental Modeling Centers, the U.S. Navy, NOAA’s National Ocean Service (NOS), as well as NOAA’s National Marine Fisheries Service (NMFS) and other oceanographers working at universities and other research institutes.
The data will be used directly in marine forecasts, providing vital information on severe winds and waves in real-time, and fed into hurricane and weather models. It will be combined with sea surface temperature in STAR’s Ocean Heat Content algorithms, to be used for tropical storm and hurricane intensity forecasting. Long term records of sea level are used in seasonal weather prediction such as predictions of El Niño and La Niña. Data is provided within a few hours of overpass, and then updated with increasing accuracy at two to three days and longer periods.
The high accuracy of the S-6B instruments like the radar altimeter allows measurements to be made very close to the coast, making this data valuable to NOAA and its partners.