ESA’s FLEX mission launches to measure vegetation health from space, with Doñana Biological Station supporting scientific validation
Launch of the Vega-C rocket from the European Spaceport in Kourou (French Guiana), carrying the FLEX and Copernicus Sentinel-3C satellites on board (Photo: ESA-CNES-Arianespace/Optique vidéo du CSG – S. Martinet).
The European Space Agency’s (ESA) FLEX (Fluorescence Explorer) mission successfully lifted off on September 15 at 03:21 (Spanish mainland time) from the European Spaceport in Kourou (French Guiana) aboard a Vega-C rocket, in the launcher’s first dual launch, alongside the Copernicus Sentinel-3C satellite.
The FLEX mission represents a major international scientific milestone as the first mission specifically designed to measure the chlorophyll fluorescence emitted by plants during photosynthesis. This signal, invisible to the human eye and extremely faint, provides direct information on photosynthetic activity, the physiological condition of vegetation, and the impact of factors such as drought, extreme temperatures, and climate change on terrestrial ecosystems.
Doñana, part of the mission’s scientific validation
The Doñana Biological Station (EBD-CSIC) is actively participating in this ambitious space programme through the SpaFLEX projects, a Spanish calibration and scientific validation initiative developed to ensure the quality of the data obtained by the satellite. The work is being carried out at several Mediterranean reference sites, including the Doñana Biological Reserve (ICTS-Doñana), and will make it possible to compare measurements taken from space with observations obtained directly on the ground.
This work is essential to ensure that the scientific products generated by FLEX, particularly those related to solar-induced fluorescence (SIF) and vegetation reflectance, accurately represent the ecosystems being observed. Field data collected by the scientific teams will make it possible to validate the information that will subsequently be used by the international research community. The EBD-CSIC’s participation is also channelled through ICTS-Doñana, a scientific infrastructure that provides facilities, equipment, and long-term environmental monitoring programmes that are essential for projects of this kind. The combination of satellite observations and field measurements makes Doñana a key reference site for assessing FLEX’s ability to monitor Mediterranean ecosystems exposed to strong environmental pressures.
Pedro Gómez and Gabriela Romero (EBD-CSIC) prepare a DJI Matrice 600 drone equipped with a Cubert hyperspectral camera during a FLEX mission validation campaign in Doñana. The data collected make it possible to compare ground-based observations with measurements from the European Space Agency’s satellite. (Photo: J. Manuel Vidal-Cordero).
A new window for observing vegetation health
FLEX’s main instrument, known as FLORIS (Fluorescence Imaging Spectrometer), will detect from space the fluorescence emitted by plants as they absorb sunlight during photosynthesis. This information will provide a direct measure of how efficiently vegetation converts solar energy and carbon dioxide into biomass.
FLEX data will be complemented by observations from Sentinel-3, which will provide near-simultaneous information on land surface temperature, land cover type, water vapour, aerosols, and other environmental variables. Combining the two missions will provide an unprecedented view of how terrestrial ecosystems function and their role in global carbon and water cycles.
Adrián Moncholí (University of Valencia) during the setup of a CableCam equipped with a Piccolo spectrometer at ICTS-Doñana as part of the SpaFLEX project, measuring vegetation fluorescence in the field—the same photosynthetic signal that the European Space Agency’s FLEX satellite will observe—and contributing to the calibration and validation of its scientific products. (Photo: J. Manuel Vidal-Cordero).
From Doñana to the global Earth system
Doñana’s participation in FLEX highlights the international importance of the environmental monitoring programmes developed by the EBD-CSIC and ICTS-Doñana. Mediterranean ecosystems are among those most vulnerable to climate change, making tools capable of assessing the physiological condition of vegetation in real time essential for understanding and anticipating how these ecosystems respond.
The information generated by FLEX will help improve ecosystem productivity models, assess the effects of droughts and other extreme events, and advance our understanding of the role of vegetation in global climate regulation. In addition to applications in ecology and global change research, the data obtained may also be useful in areas such as agriculture, natural resource management, biodiversity conservation, and global change studies.
“Field validation is an essential step in turning satellite observations into reliable scientific information. The participation of the Doñana Biological Station in SpaFLEX helps ensure that FLEX data can be used with confidence to study the health and functioning of ecosystems on a planetary scale,” comments Joaquín Cobos (EBD-CSIC).
Scientific and technical team participating in the campaign to develop calibration and validation protocols for the FLEX space mission at ICTS-Doñana. From left to right: Juan José Peón (INTA), Marcos Jiménez (INTA), M.ª Pilar Cendrero (CIDE-CSIC/University of Valencia), Cynthia Chardi-Raga (University of Valencia), Amelia Montoro (CIDE-CSIC), Pedro Gómez (EBD-CSIC), Gabriela Romero (EBD-CSIC), David Aragonés (EBD-CSIC), Adrián Moncholí (University of Valencia), Joaquín Cobos (EBD-CSIC), and César Marchante (University of Valencia) (Photo: J. Manuel Vidal-Cordero).
About ICTS-Doñana
ICTS-Doñana, a unique scientific and technological infrastructure operated by the Doñana Biological Station (EBD-CSIC), is Europe’s largest field laboratory and an international reference centre for research into biodiversity, ecology, and the impacts of global change. The infrastructure provides access to scientific equipment, environmental monitoring programmes, and specialised technical support for national and international projects, helping to generate key knowledge for the conservation and management of ecosystems.
More information about the FLEX mission: https://www.esa.int/Applications/Observing_the_Earth/FLEX_and_Sentinel-3C_launched
