The launch of Sentinel-6B, a new environmental monitoring satellite developed as part of a multibillion-dollar worldwide programme, marks a significant advancement in climate monitoring.
NASA has made a major advancement in its long-term climate monitoring mission. Launched in mid-November atop a SpaceX rocket, the satellite is expected to provide highly precise data on sea-level rise and atmospheric conditions, letting scientists follow the growing impacts of climate change.
Measuring 19.1 feet long and weighing around 2,600 pounds when fuelled, Sentinel-6B has powerful sensors capable of capturing minute changes across Earth’s oceans and atmosphere. Currently in orbit, Sentinel-6B flies about 30 seconds behind its twin, the Sentinel-6 Michael Freilich satellite.
When scientists and engineers have completed cross-calibrating the data collected by the two spacecraft, Sentinel-6B will take over the role of providing primary sea level measurements, while Sentinel-6 Michael Freilich will move into a different orbit.
Sentinel-6B: NASA’s new satellite advances sea-level and climate change research.
As per NASA, the Jason Continuity of Service mission on the Sentinel-6 spacecraft is an international partnership between the U.S. and Europe. Jason-CS/Sentinel-6 includes two identical satellites, with the first launched November 21, 2020 (Sentinel-6) and the second launched November 16, 2025 (satellite B).
These satellites will continue to detect global sea level rise, one of the most significant markers of climate change brought on by human activity, just like their predecessors. Data collected supports city planners, as well as municipal and state governments, to make informed decisions on protecting coastal infrastructure and other coastal assets.
Both satellites measure sea levels, wind speeds, and wave heights, which meteorologists feed into models that provide marine weather forecasts. The data will also enhance operational oceanography through improved forecasts of ocean currents as well as wind and wave conditions.
The sea level observations also provide information on big currents that can aid in commercial and naval navigation, search and rescue, and the tracking of debris and pollution from disasters at sea.
Key Instruments on Sentinel-6B: How NASA’s Satellite Measures Sea Levels and Atmospheric Change
NASA shows the new satellite carries several instruments to support science goals that can determine the ocean’s surface height to within a centimetre. The satellite tracks rising sea levels, which are one of the most prominent indicators of climate change.
- A radar altimeter will bounce signals off the ocean surface. Sea surface height will be determined based on the time it takes each pulse to travel from the satellite to the ocean and back again.
- An Advanced Microwave Radiometer (AMR) will retrieve the amount of water vapour between the satellite and ocean, which affects the travel speed of radar pulses.
- Radio Occultation Antennas will measure the delay of radio signals between Jason-CS and global navigation satellites (GPS) as they slice through different layers of the atmosphere.
Other onboard instruments will be used to precisely determine the satellite’s position (DORIS, Laser Retroreflector Array), perform data downlinks (S-band and X-band antennas), and supply power (Solar Array). Sentinel-6 is a combined EU and US mission.
merging the expertise of EUMETSAT, ESA, NASA, NOAA, and CNES to generate precise global sea level records. Before becoming fully operational, Sentinel-6B will undergo several months of calibration in orbit. After Sentinel 4A, Sentinel 5A, and Sentinel 1D, this launch marks the fourth successful Copernicus Sentinel mission of 2025.
