The European Space Agency's FLEX satellite has been fuelled at Europe's Spaceport in French Guiana, advancing preparations for its planned launch on 15 September at 03:21 CEST. The satellite arrived in French Guiana in mid-July after a two-week voyage by sea from Nice, France.
FLEX, the latest ESA Earth Explorer research satellite, is equipped with a Fluorescence Imaging Spectrometer designed to measure the faint glow of fluorescence emitted as plants capture light for photosynthesis. The signal, invisible to the naked eye, varies with environmental conditions and plant health, enabling scientists to detect vegetation stress before it becomes apparent on the ground.
Once launched and commissioned, FLEX will deliver the first global maps of vegetation fluorescence at a spatial resolution of 300 m × 300 m. These data will improve understanding of how carbon moves between plants and the atmosphere and how photosynthesis drives the carbon and water cycles. The satellite will carry 30 kg of highly volatile fuel to perform manoeuvres after separation from the rocket and throughout its planned minimum 3.5-year mission.
FLEX will initially fly in tandem with the Sentinel-3A satellite, which will provide complementary measurements of clouds, aerosols and water vapour, alongside information about the land surface, including surface temperature and land-cover type. The near-simultaneous observations from both satellites will provide an unprecedented view of the function and condition of vegetation across the globe.
Frank de Bruin, ESA's Launch Campaign Manager for FLEX, said fuelling preparations had gone "very well" and that the satellite was "now fully loaded." The next steps involve installing FLEX on its launcher adapter before encapsulating it into the lower position of the Vega-C rocket fairing.
