Europe entered a new, advanced era of weather and climate change monitoring early this morning, August 13, 2025, with the launch of the first satellite from the revolutionary MetOp Second Generation (MetOp-SG) series. From the European spaceport in Kourou, French Guiana, a powerful Ariane 6 rocket soared into polar orbit, carrying a satellite with technology crucial for the future of our planet. A key part of this sophisticated package is the Copernicus Sentinel-5 instrument, designed for the most precise monitoring to date of air pollutants, the state of the ozone layer, and climate-related gases.

At exactly 2:37 AM Central European Time (last night at 9:37 PM local time), Ariane 6 took off, carrying the four-tonne satellite in its cargo bay. The moments of tension ended at 4:47 AM, when confirmation arrived from the space center that the MetOp-SG-A1 satellite had successfully reached orbit and, most importantly, that its solar panels had deployed correctly. This crucial step has ensured the satellite's autonomous power supply, officially starting its mission.

A revolution in weather and climate monitoring

The MetOp Second Generation mission is a direct successor and a significant improvement on the first generation of MetOp satellites, which have been the backbone of the European system for collecting meteorological data from polar orbit in recent years. The new series not only ensures the continuity of vital data delivery for global weather forecasts and climate analyses but also brings dramatically improved capabilities. The entire MetOp-SG mission consists of three successive pairs of satellites, meaning a total of six spacecraft that will watch over the Earth for the next twenty years. Each pair consists of an 'A' type satellite and a 'B' type satellite, each carrying a different but complementary set of state-of-the-art instruments. This design allows them to collectively gather a comprehensive spectrum of data on the atmosphere, oceans, and land.

This first launched satellite, designated MetOp-SG-A1, belongs to the 'A' type and carries the Sentinel-5 spectrometer, a key instrument for the Copernicus programme, the European Union's Earth observation component. Its partner, MetOp-SG-B1, is scheduled for launch next year to complete the first pair in orbit.

A powerful partnership for the future of the planet

This extremely complex mission is the result of a long-standing and strong collaboration between the European Space Agency (ESA) and Eumetsat, the European Organisation for the Exploitation of Meteorological Satellites. Within this partnership, ESA was responsible for the design, development, and construction of the satellites themselves, ensuring the technology met the highest standards. On the other hand, Eumetsat takes on the management of launch services, the development of the ground segment for control and data acquisition, in-orbit satellite operations, and the distribution of invaluable data to meteorological communities worldwide.

Simonetta Cheli, Director of ESA's Earth Observation Programmes, highlighted the importance of the collaboration: "Today's launch underscores the value of strong partnerships between ESA, Eumetsat, the European Commission, Arianespace, and the entire European space industry. Given the increasingly unpredictable weather patterns, timely and accurate forecasting has never been more important, and the MetOp-SG mission is now ready to play a key role in improving weather forecasts and climate monitoring. Sentinel-5 will also deliver timely data for monitoring air pollution and much more."

Her words were echoed by Phil Evans, Director-General of Eumetsat: "Extreme weather has cost Europe hundreds of billions of euros and tens of thousands of lives over the last 40 years. Storms, record-breaking heatwaves, and fierce wildfires are just the latest reminders of this harsh reality. The launch of MetOp-SG-A1 is a major step forward in providing sharper tools to national weather services in our member states, tools that save lives, protect property, and build resilience to the climate crisis." Evans also emphasized the global importance of the mission, noting that MetOp-SG-A1 is the first European contribution to the Joint Polar System with the US agency NOAA, reflecting years of teamwork and international cooperation.

Sophisticated instruments: Eyes in orbit

The MetOp-SG-A1 satellite is equipped with six state-of-the-art instruments, each with a specific and irreplaceable role in collecting data on the state of the Earth's system.

• Sentinel-5 spectrometer: This instrument is the heart of the mission when it comes to air quality monitoring. It will map the concentrations of key atmospheric gases daily, including nitrogen dioxide, sulphur dioxide, ozone, methane, carbon monoxide, and formaldehyde. The data it collects will be sent directly to the Copernicus Atmosphere Monitoring Service (CAMS), allowing authorities to track pollution sources, predict episodes of poor air quality, and inform the public.


• Infrared Atmospheric Sounding Interferometer – New Generation (IASI-NG): This hyperspectral instrument measures the infrared radiation emitted by the Earth. By analyzing this radiation, IASI-NG can create extremely detailed vertical profiles of temperature and humidity in the atmosphere with unprecedented accuracy, which is fundamental for more accurate numerical weather predictions.


• Microwave Sounder (MWS): Unlike infrared instruments, microwave sensors can "see" through clouds. The MWS will provide key data on temperature and water vapour in all weather conditions, day and night, filling in the gaps that other instruments cannot cover.


• Multi-viewing, Multi-channel, Multi-polarisation Imager (METimage): This instrument provides high-resolution images of clouds, land surfaces, and ice in 20 different spectral channels. Data from METimage will be used for cloud analysis, measuring sea surface temperature, monitoring snow and ice cover, and assessing vegetation health.


• Multi-Angle, Multi-Channel, Multi-Polarisation Imager (3MI): A unique instrument that observes the same point on Earth from 14 different angles and in different polarisations of light. This allows it to provide detailed information on atmospheric aerosols – tiny particles of dust, soot, and salt – which have a significant impact on climate and air quality.


• Radio Occultation Sounder (RO): Using signals from navigation satellites like GPS, this instrument measures how these signals are refracted as they pass through the Earth's atmosphere. From these subtle changes, extremely precise profiles of temperature, pressure, and humidity can be calculated.

A look into the future: What's next?

Following a successful launch, the MetOp-SG-A1 satellite enters the so-called in-orbit verification phase. Over the next few months, teams of engineers and scientists on Earth will carefully test and calibrate all systems and instruments to ensure they are working flawlessly and providing the highest quality data. Marc Loiselet, ESA's MetOp-SG mission project manager, expressed his satisfaction: "It is wonderful to know that the first satellite in the series is now safely in orbit. We will monitor it closely during the verification phase. Both types of satellites are extremely complex, so I would also like to thank everyone who was involved in the development and its journey to orbit."

Although the focus is currently on the first satellite, eyes are already on the future. Its partner satellite, MetOp-SG-B1, is already in an advanced stage of preparation, and its launch is planned for next year. The 'B' type satellites will carry a complementary set of instruments, including a Scatterometer (SCA) for measuring ocean winds, a Microwave Imager (MWI) for monitoring precipitation and sea ice concentration, and an innovative Ice Cloud Imager (ICI), the first of its kind. They will also have an Argos-4 data collection system, which collects signals from thousands of scientific buoys and platforms on Earth. Finally, it is important to note that the MetOp-SG satellites are the first satellites developed by ESA to carry an active disposal system for the end of their mission. Each satellite is equipped with an additional thruster that will allow it to perform a controlled de-orbit into the Earth's atmosphere at the end of its operational life, leaving no dangerous space debris behind and demonstrating a commitment to the responsible use of space.