6 Things to Know From NASA About New US, European Sea Satellite

by JPL Staff Writers
Pasadena CA (JPL) Nov 15, 2025

Data from Sentinel-6B will continue a decades-long record of sea surface height, helping to improve coastal planning, protect critical infrastructure, and advance weather forecasts.

With launch set for no earlier than 12:21 a.m. EST Monday, Nov. 17, Sentinel-6B is the latest satellite in a series of spacecraft NASA and its partners have used to measure sea levels since 1992. Their data has helped meteorologists improve hurricane forecasts, managers protect infrastructure, and coastal communities plan.

After launch, Sentinel-6B will begin the process of data cross-calibration with its predecessor, Sentinel-6 Michael Freilich, to provide essential information about Earth's ocean.

Sentinel-6B is the second of two satellites that constitute the Sentinel-6/Jason-CS (Continuity of Service) mission, a collaboration between NASA, ESA (European Space Agency), EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites), and the National Oceanic and Atmospheric Administration (NOAA). The European Commission contributed funding support while France's space agency CNES (Centre National d'Etudes Spatiales) provided technical expertise.

Here are six things to know about Sentinel-6B and the broader Copernicus Sentinel-6/Jason-CS mission:

1. Sentinel-6B will deliver data on about 90% of Earth's ocean, providing direct benefits to humanity.

Sentinel-6B will contribute to a multidecade dataset for sea level measurements from space. This data is key to helping improve public safety, city planning, and protecting commercial and defense interests.

Pioneered by NASA and its partners, the dataset enables users in government, industry, and the research community to better understand how sea levels change over time. Combined with information from other NASA satellites, data from Copernicus Sentinel-6/Jason-CS is vital for tracking how heat and energy move through Earth's seas and atmosphere, as well as for monitoring ocean features such as currents and eddies. The measurements come courtesy of a radar altimeter that measures sea levels for nearly all of Earth's ocean, providing information on large-scale currents that can aid in commercial and naval navigation, search and rescue, and the tracking of debris and pollutants from disasters at sea.

2. Data from the Copernicus Sentinel-6/Jason-CS mission helps NASA prepare for the next phase of space exploration.

The better we understand Earth, the better NASA can carry out its mission to explore the universe. Data from the Copernicus Sentinel-6/Jason-CS mission is used to refine the Goddard Earth Observing System atmospheric forecast models, which the NASA Engineering Safety Center uses to plan safer reentry of astronauts returning from Artemis missions.

Additionally, changes to Earth's ocean, observed by satellites, can have measurable effects beyond our planet. For instance, while the Moon influences ocean tides on Earth, changes in those tides can also exert a small influence on the Moon. Data from Copernicus Sentinel-6/Jason-CS can help improve understanding of this relationship, knowledge that can contribute to future lunar exploration missions.

3. The Copernicus Sentinel-6/Jason-CS mission helps the U.S. respond to challenges by putting actionable information into the hands of decision-makers.

Data collected by the mission helps city planners, as well as local and state governments, to make informed decisions on protecting coastal infrastructure, real estate, and energy facilities. The mission's sea level data also improves meteorologists' weather predictions, which are critical to commercial and recreational navigation. By enhancing weather prediction models, data provided by Copernicus Sentinel-6/Jason-CS improves forecasts of hurricane development, including the likelihood of storm intensification, which can aid disaster preparedness and response.

4. Data from Sentinel-6B will support national security efforts.

The ocean and atmosphere measurements from Sentinel-6B will enable decision-makers to better protect coastal military installations from such events as nuisance flooding while aiding national defense efforts by providing crucial information about weather and ocean conditions. The satellite will do so by feeding near-real time data on Earth's atmosphere and seas to forward-looking weather and ocean models. Since the measurements are part of a long-term dataset, they also can add historical context that puts the new data in perspective.

5. The Copernicus Sentinel-6/Jason-CS mission's direct observation of sea levels delivers information critical to protecting coastlines, where nearly half of the world's population lives.

Sea level rise varies from one area to another, meaning that some coastlines are more vulnerable than others to flooding, erosion, and saltwater contamination of underground freshwater supplies, the latter of which threatens farmland and drinking water. Sea level measurements from Sentinel-6 Michael Freilich, and soon, Sentinel-6B, form the basis of U.S. flood predictions for coastal infrastructure, real estate, energy storage sites, and other coastal assets. Knowing which regions are more vulnerable to these risks will enable U.S. industries and emergency managers to make better-informed decisions about transportation and commercial infrastructure, land-use planning, water management, and adaptation strategies.

6. The international collaboration behind the mission enables the pooling of capabilities, resources, and expertise.

The multidecadal dataset that this mission supports is the result of years of close work between NASA and several collaborators, including NASA, ESA, EUMETSAT, CNES, and NOAA. By pooling expertise and resources, this partnership has delivered cost-effective solutions that have made precise, high-impact data available to industry and government agencies alike.