Published on 6 March 2025
Air pollution is one of Europe’s most pressing environmental and public health challenges. To ensure the continued growth of Copernicus Earth Observation (EO) data and services, the European Commission is expanding the Copernicus constellation with new satellite missions in 2024 and 2025. Among them, Copernicus Sentinel-4, set to launch in summer 2025, will be Europe’s first geostationary air quality monitoring mission, providing hourly, high-resolution data on pollutants such as ozone (O₃), nitrogen dioxide (NO₂), formaldehyde (HCHO), and sulphur dioxide (SO₂).
Europe’s first geostationary air quality monitoring mission
With the launch of Copernicus Sentinel-4, the EU reinforces its position as a global leader in space-based Earth Observation. This satellite mission expands the capabilities of Copernicus, providing high-resolution and near real-time air quality monitoring to support health, environmental and climate policies.
Unlike previous Sentinel satellites, Sentinel-4 is not an independent spacecraft but a hosted payload onboard EUMETSAT’s MTG-Sounder (MTG-S) satellite. This innovative "one satellite, two missions" approach allows Sentinel-4 to work in synergy with the Infrared Sounder (IRS) instrument, providing simultaneous and co-located meteorological and atmospheric monitoring data. Sentinel-4 caries an Ultraviolet Visible Near-infrared (UVN) spectrometer, able to measure key pollutants with high precision, including ozone (O₃), nitrogen dioxide (NO₂), formaldehyde (HCHO), sulphur dioxide (SO₂), and aerosols. In addition, the mission will incorporate data from EUMETSAT’s IRS, which contributes to climate and atmospheric composition analysis, and will later integrate data from the Flexible Combined Imager (FCI) on the MTG-Imager satellite.
Preparing for launch
As the MTG-S satellite, carrying the Sentinel-4 payload, prepares for launch in summer 2025, a cleanroom visit in Bremen gives key stakeholders, scientists, and media representatives a final look before it is transported to the launch site and integrated in the launch vehicle. This will be the last opportunity to view the spacecraft before it embarks on its mission.