ESA's photosynthesis mission

The planet’s growing global population is placing mounting pressure on the production of food, animal feed, biological fuels and pharmaceutical products. It is estimated that there will have to be more than a 50% increase in agricultural production by 2050 to meet demand. Understanding plant health and productivity is therefore essential to manage resources.

It is now an undeniable fact that human activity is leading to global change, the consequences of which are far-reaching. More than ever, effective methods are needed to assess how a warming climate and global change are affecting the health and productivity of Earth’s vegetation so that mitigation and adaption strategies can be put in place.

Although photosynthesis is one of the most fundamental processes on the planet, it has not been possible to measure it directly on large spatial scales. However, when plants photosynthesise, they emit a faint fluorescent glow.

This glow is invisible to the naked eye, but, remarkably, it can be measured from space.

Using novel technology, the Fluorescence Explorer (FLEX) – ESA’s eighth Earth Explorer mission – will shed new light on the functioning of our vegetation. The FLEX satellite will carry an instrument called the Fluorescence Imaging Spectrometer (Floris) to measure this fluorescent signal.

The information will be used to assess the functioning, health and stress of plants.

FLEX will orbit in tandem with one of the Copernicus Sentinel-3 satellites, which will be used to provide information on the atmosphere such as clouds, aerosols and water vapour as well as information about the land, such as the surface temperature and type of land cover. This information will contribute to the integrated package of measurements.