Two European Earth-observation satellites have reached orbit after a Vega-C launch from French Guiana, opening a new phase of climate and environmental monitoring. The FLEX mission will examine how plants respond to heat and water stress, while Sentinel-3C will collect data on oceans, land, ice and the atmosphere.
The satellites were launched together on the VV30 mission from the European spaceport in Kourou at 22:21 on Monday. Although they shared the journey into space, FLEX and Sentinel-3C will operate in different orbits so their observations can later be combined.
What the FLEX satellite will study
FLEX is designed to improve understanding of photosynthesis, the process through which plants convert light into energy. Its scientific instrument can detect a faint form of light released by vegetation during photosynthesis, a signal that is not visible to the human eye.
That signal can reveal how plants are functioning and whether they are being affected by environmental stress. By monitoring vegetation activity, researchers hope to identify the effects of conditions including extreme heat and water shortages.
The satellite is expected to produce vegetation-activity maps with a resolution of approximately 300 metres by 300 metres. The mission is planned to operate for at least three and a half years.
Why plant monitoring matters
Vegetation plays a central role in the climate system. Plants absorb carbon dioxide, influence water cycles and support ecosystems and food production. However, the effects of drought and high temperatures can vary significantly between regions and plant types.
FLEX’s observations will provide scientists with additional information about how vegetation responds to changing conditions. Combined with measurements from other Earth-observation missions, the data could help researchers assess environmental change more precisely.
Sentinel-3C strengthens Copernicus monitoring
The second spacecraft, Sentinel-3C, is part of the European Union’s Copernicus programme, which provides Earth-observation data for environmental monitoring and public services.
Sentinel-3C will observe several parts of the planet’s physical environment, including:
- Oceans and coastal areas
- Land surfaces
- Sea and terrestrial ice
- The atmosphere
- Changes relevant to weather and climate analysis
Its data will support activities such as improving weather forecasts and tracking how the climate and environment are changing over time.
Sentinel-3C will join Sentinel-3A and Sentinel-3B in the wider mission. It is intended to replace Sentinel-3A, which has been operating since 2016.
How the two missions will work together
FLEX and Sentinel-3C are not duplicates. FLEX focuses specifically on plant function and photosynthetic activity, while Sentinel-3C provides broader observations of land, oceans, ice and the atmosphere.
Operating in separate orbits will allow scientists to compare vegetation signals with wider environmental conditions. For example, plant stress detected by FLEX can be examined alongside information about surface temperature, water conditions or atmospheric patterns recorded by other instruments.
This combined approach is important because plant health is influenced by multiple factors. Satellite data can provide observations across large areas, helping scientists study environmental changes that may be difficult to track consistently from the ground.
European and Spanish involvement
The launch is part of Europe’s expanding investment in space-based climate observation through the European Space Agency and the Copernicus programme.
Spain has a prominent scientific role in FLEX. José Moreno, a professor at the University of Valencia, is the mission’s principal investigator and leads its scientific team. Spain’s Ministry of Science has also highlighted the country’s contribution to the European Space Agency project.
The mission illustrates how European space projects bring together launch infrastructure, scientific institutions and public Earth-observation programmes. The resulting data are intended for research and environmental assessment rather than commercial imaging alone.
What happens next?
Following launch, the satellites must complete their initial deployment and commissioning phases before routine scientific operations begin. Their instruments will then be calibrated and checked so researchers can assess the quality and consistency of the measurements.
FLEX’s planned observations will add a new layer to climate research by focusing on the functioning of vegetation, not only its visible appearance. Sentinel-3C will help maintain continuity in the broader Sentinel-3 monitoring system as it takes over from the older spacecraft.
The launch does not itself create a new climate policy or binding environmental rule. Instead, it provides scientific evidence that can support future research, forecasting and environmental decision-making in Europe and beyond.
Conclusion
The FLEX and Sentinel-3C launch expands Europe’s ability to observe the planet from space. FLEX will track the way vegetation responds to heat and limited water, while Sentinel-3C will continue wide-ranging monitoring of oceans, land, ice and the atmosphere. Together, the missions should give scientists a clearer picture of how climate change is affecting ecosystems and the wider Earth system.
