ESA’s Biomass satellite in the anechoic test chamber at Airbus Defence and Space in Toulouse, France on 27 January 2025. Biomass is the first satellite to carry a P-band synthetic aperture radar in space to measure forest biomass and height across different forest types.

Thanks to the long 70 cm wavelength of P-band, the signal can penetrate through the forest canopy, allowing it to collect information on amounts of different parts of the forest, namely, tree trunks, branches and stems – which is where trees store most of their carbon. Since carbon makes up roughly half the weight of wood, the mission is extremely important in the quest to reduce uncertainties about the role forests play in the global carbon cycle and in our climate system.