On September 15, 2026, at 3:21 AM (CEST), the FLEX (Fluorescence EXplorer) satellite lifted off from the Kourou launch site in French Guiana aboard a Vega-C rocket, accompanied by the Sentinel-3C satellite. These two European Space Agency (ESA) missions will work in tandem to gather new data on the health of vegetation. In particular, FLEX will quantify chlorophyll fluorescence emissions with unprecedented resolution. This faint red glow is produced by plants during photosynthesis and provides crucial information on how they adapt to extreme environmental conditions—such as droughts and heatwaves—helping to anticipate the impact on carbon and water cycles.

This launch marks the culmination of over 20 years of preparatory work, to which the LMD actively contributed through modeling, instrument development, and multi-scale studies of the fluorescence signal under natural conditions. FLEX is currently en route to its final orbit, which it is expected to reach by mid-October. First data for the early calibration and validation phases are anticipated within a few weeks.

More information here: https://www.esa.int/Applications/Observing_the_Earth/FutureEO/FLEX