In anticipation of one of the most significant space endeavors of this year, all eyes are on the European Space Centre in Kourou, French Guiana. Tomorrow, on August 13, 2025, at exactly 02:37 Central European Time (which is 21:37 local time on August 12), the powerful Ariane 6 rocket will begin its flight, carrying a satellite into orbit that promises to revolutionize the way we observe and understand weather, climate, and air quality on our planet. This is the MetOp-SG-A1 satellite, the first of a new generation of European meteorological satellites, which also hosts the key Copernicus Sentinel-5 instrument, thus beginning a new era of comprehensive Earth observation.

The final preparations for the launch are taking place in an atmosphere of surgical precision. Recently released time-lapse footage from Kourou provides a rare insight into the complexity and meticulousness of this process. The cameras have captured key phases, from the hermetic sealing of the satellite inside the Ariane 6 rocket's protective shield, known as the "fairing," to its careful placement on top of the launch pad. Every movement, every bolt, and every check is part of a chain of actions designed to ensure a flawless start to a mission that will serve humanity for decades.

A new generation for more accurate forecasts and a deeper understanding of the climate

MetOp-SG-A1 is not just another satellite in a series; it is a herald of a new era in meteorology and climatology. As the first in a series of a total of three pairs of second-generation satellites (MetOp-SG), this satellite represents a quantum leap compared to its predecessors from the first MetOp mission. The main goal of the mission is to ensure the continuous delivery of key data from polar orbit over the next two decades, but what MetOp-SG brings is a dramatic improvement in the accuracy and resolution of observations. In practice, this means that meteorological services around the world will receive data that will enable the creation of significantly more reliable and detailed weather forecasts. From predicting the path of hurricanes with greater certainty to more precise planning in agriculture and transport, the impact of this mission will be felt in everyday life.

In addition to improving existing measurement techniques, MetOp-SG-A1 also brings entirely new measurement capabilities that will expand the scientific scope of the mission. The instruments on the satellite will be able to measure wind over the oceans, analyze the composition of the atmosphere with unprecedented precision, and monitor the water cycles on Earth. This data is key to better understanding climate change, validating climate models, and monitoring the global trends that are shaping the future of our planet.

Two types of satellites for a complete picture

The MetOp-SG program is based on an innovative concept that includes two different types of satellites, designated as 'A' and 'B' satellites, which will be launched in pairs. MetOp-SG-A1, which is currently being prepared for launch, is the first 'A' type satellite. These satellites are primarily equipped with instruments for atmospheric sounding in the visible, infrared, and microwave spectrums, as well as instruments for imaging clouds and the Earth's surface. Their main task is to create detailed three-dimensional profiles of atmospheric temperature and humidity, which is the foundation for modern numerical weather prediction.

On the other hand, the 'B' type satellites, which are planned for future launch, will carry a different set of instruments, primarily focused on high-resolution microwave imaging. These instruments will enable precise measurement of sea ice, soil moisture, wind speed over the ocean, and other key parameters. The combination of data from the 'A' and 'B' satellites will provide scientists and forecasters with the most complete picture of the Earth system to date, allowing them to connect different processes and create far more sophisticated models.

Copernicus Sentinel-5: a watchful eye over our atmosphere

One of the most important components of the MetOp-SG-A1 satellite is the Sentinel-5 instrument, a key part of the European Earth observation program Copernicus. While MetOp primarily deals with weather and climate, Sentinel-5 has a specific and vital task: daily global monitoring of air quality. This sophisticated spectrometer will measure the concentrations of a whole range of atmospheric trace gases and pollutants, including ozone, nitrogen dioxide (NO₂), sulfur dioxide (SO₂), carbon monoxide (CO), methane (CH₄), and formaldehyde.

The data that Sentinel-5 will collect is of invaluable importance for protecting public health, as it will enable precise monitoring of pollution sources, the spread of polluted air masses, and the effectiveness of emission reduction measures. Scientists will be able to track volcanic ash that can threaten air traffic, detect industrial accidents, and analyze long-term trends in atmospheric composition related to climate change. Furthermore, the mission will also monitor aerosols – tiny particles in the air – and the level of ultraviolet radiation reaching the Earth's surface, providing important information for UV index forecasts and public warnings.

Ariane 6: Guarantor of European independence in space

The launch of the MetOp-SG-A1 satellite is also an important moment for the Ariane 6 rocket. This new heavy-lift launch system, developed under the auspices of the European Space Agency (ESA), represents the future of European access to space. Designed to be more versatile and cost-effective than its predecessor, Ariane 5, the Ariane 6 rocket is key to ensuring European autonomy in placing strategic satellites into orbit, whether they are for telecommunications, navigation, scientific, or, as in this case, meteorological missions. Its ability to reach different orbits and carry various payloads makes it a cornerstone of European space ambitions for the coming decades. The launch from French Guiana, due to its proximity to the equator, provides additional energy efficiency, allowing the rocket to carry a heavier payload into orbit.

Tomorrow's launch is therefore not just the beginning of a scientific mission, but also a confirmation of the successful collaboration between key European organizations. The development of the satellite was led by ESA, while the operational management of the mission and data distribution will be carried out by EUMETSAT (the European Organisation for the Exploitation of Meteorological Satellites), all under the broader umbrella of the European Union's Copernicus program. Together, they are launching a system that will help us better prepare for severe weather events, adapt to climate change, and breathe cleaner air.