FLEX Mission

The FLuorescence EXplorer (FLEX) is a planned mission by the European Space Agency to launch a satellite to monitor the global steady-state chlorophyll fluorescence in terrestrial vegetation. FLEX was selected for funding on 19 November 2015 and will be launched on a Vega C rocket from Guiana Space Centre in mid-2026 together with another Earth-observing satellite, Altius.

Overview

The FLuorescence EXplorer (FLEX) mission is the eighth mission in the Earth Explorer programme, (part of ESA's Living Planet Programme). It comprises a satellite for the global monitoring of steady-state chlorophyll fluorescence in terrestrial vegetation. Leaf photosynthesis releases energy not required in the biochemical process in the form of light in wavelength between 640 and 800 nanometres.

After more than 70 years of basic and applied research in chlorophyll fluorescence, it is now established that fluorescence is a sensitive indicator of photosynthesis in both healthy and physiologically perturbed vegetation that can be used to monitor croplands and forests.

Fluorescence is a powerful non-invasive tool to track the status, resilience, and recovery of photochemical processes, and provides important information on overall photosynthetic performance with implications for related carbon sequestration. The early responsiveness of fluorescence to atmospheric, soil and plant water balance, as well as to atmospheric chemistry and human intervention in land usage, makes it a useful biological indicator in improving the understanding of Earth system dynamics.

FLEX will encompass a three-instrument array for measurement of the interrelated features of fluorescence, hyperspectral reflectance, and canopy temperature.

The program will involve a space and ground-measurement program of 3-years duration and will provide data formats for research and applied science.

Timeline

* In November 2015, ESA has selected FLEX as the agency's eighth Earth Explorer mission.
* In November 2016, ESA has selected Italian company Leonardo to build the main instrument (Floris) for the FLEX satellite.
* In 2018, during the first FLEXSense campaign, the OLCI instruments of the Sentinel-3B satellite was reprogrammed to operate in a mode simulating the future cooperations with FLEX and a parallel aerial campaign used aircraft-based observations to demonstrate aspects of the Floris instrument functionality.
* In January 2019, ESA has selected Thales Alenia Space as the prime contractor for the satellite and to oversee the development of the Floris instrument by Leonardo.
* In summer 2019, the second FLEXSense campaign took place, with operations closely following the 2018 campaign.
* In January 2022, ESA has signed a contract with Arianespace for a joint launch of FLEX and Altius on Vega C.
* In December 2023, Thales Alenia Space selected the UK’s National Satellite Test Facility for the satellite's first comprehensive assembly, integration and test campaign.
* In 2024, the Fraunhofer IOF in Jena was exhibiting the double-slit assembly, which it had developed for the Floris instrument, at SPIE Photonics West in San Francisco.

See also

* List of European Space Agency programmes and missions
* Photosynthetic efficiency
* Phototroph

References

External links

FLEX
- Report to ESA for mission selection
*Workshops on the FLEX mission
2014FLEX Photosynthesis StudyFLEX Bridge StudyFLEX (Fluorescence Explorer) article on eoPortal

{{Future spaceflights

Fluorescence
Ecological metrics
Earth observation satellites of the European Space Agency
2026 in spaceflight
Proposed satellites
Spectrometers