SpaceX Successfully Launches Sentinel-6B for Ocean Monitoring

A Falcon 9 rocket launched the Sentinel-6B ocean monitoring satellite on November 17, 2025, marking a significant step in a joint NASA-European initiative aimed at tracking long-term changes in sea level, a critical indicator of climate change. The satellite lifted off from the Vandenberg Space Force Base in California at 12:21 a.m. EST, continuing a billion-dollar project that began with the launch of the first satellite, Sentinel-6, in November 2020.

The Sentinel-6 satellites are equipped with advanced cloud-penetrating radar technology. By measuring the time it takes for radar signals to bounce back from the ocean, Sentinel-6B can determine sea levels with an accuracy of about one inch, while also measuring wave heights and wind speeds. This data plays an essential role in understanding sea level rise, which has been linked to global warming primarily driven by human activities.

Although the project contributes vital information to climate research, NASA’s pre-launch briefing for Sentinel-6B notably avoided direct references to “climate change” or “global warming.” Karen St. Germain, director of NASA’s Earth Science Division, emphasized the practical applications of the new satellite instead. She stated, “Sentinel 6B is the latest in a line of missions stretching over three decades, keeping an uninterrupted watch over our planet’s sea surface height.”

The data generated by the Sentinel-6 satellites will support various sectors, including navigation, search and rescue operations, and industries such as commercial fishing and shipping. St. Germain noted that the measurements are essential for U.S. flood predictions and for assessing risks to coastal infrastructure and real estate. Additionally, this information is crucial for understanding coastal erosion and the encroachment of saltwater into freshwater supplies used for agriculture and drinking.

The launch proceeded smoothly, with the Falcon 9 rocket’s first stage separating successfully and returning to a landing pad at the launch site. The upper stage then completed two engine firings before deploying the 2,600-pound Sentinel-6B into an orbit approximately 830 miles above Earth, angled at 66 degrees to the equator. This orbit allows the satellite to cover around 90 percent of the world’s oceans during its 112-minute orbit.

In addition to monitoring sea levels, Sentinel-6B will also gather data on temperature and humidity in both the lower atmosphere and the stratosphere. This will be achieved using instruments that measure atmospheric effects on signals from navigation satellites.

The project is the result of a collaboration between NASA, the European Space Agency, the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT), and the National Oceanic and Atmospheric Administration. NASA’s financial contribution to both Sentinel-6 satellites totaled approximately $500 million, with European partners matching that amount.

As the world faces the challenges posed by climate change, the launch of Sentinel-6B reinforces the ongoing commitment to understanding and addressing the impacts of rising sea levels. The data gathered will be instrumental in planning for the future and safeguarding coastal communities around the globe.