Two days ago, on Wednesday, August 13, 2025, Europe stepped into a new era of Earth observation with the launch of the most technologically advanced meteorological satellite to date. From Europe's spaceport in Kourou, French Guiana, at exactly 02:37 Central European Time, the powerful Ariane 6 rocket soared into the night sky, carrying the first satellite of the MetOp Second Generation series, named MetOp-SG-A1, into orbit. This event represents a crucial moment not only for the future of weather forecasting and climate monitoring, but also for European autonomy in space access, confirming the capabilities and ambitions of the European space program.

The MetOp-SG-A1 satellite is not just a successor to the previous, extremely successful MetOp mission, but a significant technological leap forward. It is designed to provide data of incomparably greater precision and resolution, which will enable the creation of more reliable and detailed short- and medium-term weather forecasts. In addition, it carries a key instrument of the Copernicus program, Sentinel-5, whose task is the daily global monitoring of air quality and the concentration of atmospheric trace gases. Thus, this mission combines two vital aspects of observing our planet: meteorology and atmospheric monitoring, providing a comprehensive picture of the complex processes that shape our environment.

A new generation of meteorological observation

The MetOp Second Generation (MetOp-SG) program is a joint undertaking of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and the European Space Agency (ESA), designed to ensure the continuity and significant improvement of key meteorological data from polar orbit for the next two decades. Unlike the first generation, this program is based on a system of two different satellites, designated as the A-series and the B-series, which will operate in tandem. Each series carries a complementary set of instruments, thereby achieving a comprehensiveness of measurement that was not possible before.

The MetOp-SG-A1 satellite, as the first in the series, is focused on optical and atmospheric sounding, while the B-series satellites, planned for future launch, will be equipped with instruments for microwave measurements. Together, these two types of satellites will provide a three-dimensional picture of the atmosphere, from air temperature and humidity, to cloud characteristics and ocean winds, to the detailed composition of the atmosphere. The data they collect will form the basis for numerical weather prediction models, allowing meteorologists to predict extreme weather events such as storms, heatwaves, or heavy precipitation with greater certainty, which directly contributes to the safety of citizens and the protection of property.

The heart of the satellite: Sophisticated measuring instruments

What makes MetOp-SG-A1 revolutionary is its package of six state-of-the-art instruments, each with a specific role in scanning the Earth's atmosphere, oceans, and land. Among the most important is the Infrared Atmospheric Sounding Interferometer - New Generation (IASI-NG). This instrument will measure temperature and humidity in the atmosphere with extraordinary vertical resolution, while also tracking the concentrations of greenhouse gases and other trace gases, which is crucial for climate modeling.

Alongside it is METimage, an advanced radiometer that captures images of the Earth in the visible and infrared spectrum, providing detailed information on clouds, snow cover, vegetation, and sea surface temperature. The Microwave Sounder (MWS) will enable the measurement of temperature and water in the atmosphere even through clouds, which was one of the challenges for previous generations of satellites. There is also a completely new instrument, the 3MI (Multi-viewing Multi-channel Multi-polarisation Imager), which will provide unique data on aerosols – tiny particles in the atmosphere that affect air quality and climate, and whose behavior has been difficult to model accurately until now. All these instruments together create a synergy that will give scientists and forecasters a powerful tool for understanding the Earth's system.

Guardian of the atmosphere: The Copernicus Sentinel-5 mission

The Sentinel-5 instrument, a key part of the European Earth observation program, Copernicus, adds special value to the MetOp-SG-A1 satellite. Its primary task is the global mapping of atmospheric composition with an unprecedented level of detail. Sentinel-5 will daily measure the concentrations of key air pollutants and greenhouse gases, including nitrogen dioxide, ozone, sulfur dioxide, methane, carbon monoxide, and formaldehyde. This data is invaluable for monitoring industrial pollution, the impact of traffic on air quality in cities, detecting and tracking forest fires, and for understanding global climate change.

The precision and reach of Sentinel-5 will allow authorities worldwide to make informed decisions on environmental and public health protection. Tracking the movement of pollution clouds across continents will help to better understand transboundary impacts, while data on UV radiation will be used to issue timely warnings to the public. By integrating this powerful instrument onto a meteorological satellite, Europe has created a unique platform that simultaneously addresses the challenges of weather, climate, and air quality.

Ariane 6: Europe's autonomous access to space

The launch of the MetOp-SG-A1 satellite was also an important test for the new European heavy-lift rocket, Ariane 6. Developed by ArianeGroup as part of an ESA program, Ariane 6 is designed to provide Europe with independent, reliable, and competitive access to space for the coming decades. Its modular construction allows for adaptation to various missions, and for this launch, designated VA264, a configuration with two solid fuel boosters was used.

The successful placement of such a valuable and complex satellite into a precisely defined polar, sun-synchronous orbit at an altitude of about 830 kilometers is a confirmation of the reliability and performance of the Ariane 6 rocket. A sun-synchronous orbit is key for this type of mission as it allows the satellite to fly over every point on Earth at the same local solar time. This ensures consistent lighting conditions on each pass, which is crucial for comparing data and tracking changes over time. This success strengthens Europe's position as a key player in the global space market and ensures that future European scientific, meteorological, and commercial missions will have a secure path to space.