The European Space Agency's (ESA) BIOMASS mission is a pioneering Earth observation satellite mission launched on April 29, 2025. Utilizing a P-band synthetic aperture radar (SAR), the objective of BIOMASS is to deliver estimates of above-ground forest biomass, forest height (FH), and forest disturbance (FD), with unprecedented accuracy. The mission's primary scientific goal is to quantify the distribution and changes in forest biomass, thereby reducing uncertainties in carbon flux estimates and informing climate models. The satellite's advanced instrumentation and innovative approach allow it to penetrate dense forest canopies, capturing data even in challenging environments. The mission will operate in two distinct phases: the tomographic phase and the interferometric phase, which will support polarimetric interferometric SAR (Pol-InSAR) and tomographic SAR (TomoSAR) processing. Additionally, BIOMASS will provide valuable observational data for ice sheets, deserts, the ionosphere, below canopy topography, and other domains.

The Biomass mission is the 7th Earth Explorer Mission within the frame of the ESA Earth Observation Programme. The primary objective of Biomass is to determine the worldwide distribution of forest above-ground biomass in order to reduce the major uncertainties in calculations of carbon stocks and fluxes associated with the terrestrial biosphere. To meet these objectives Biomass will carry, for the first time in space, a fully polarimetric P-band synthetic aperture radar (SAR) supporting also interferometric acquisitions. This paper provides an overview of the Biomass system design and development status.

Biomass, ESA's 7th Earth Explorer mission, will provide the first global scale, systematic measurements of the global distribution of biomass. This paper describes the Biomass mission architecture, an overview of the Biomass satellite design (instrument, Large Deployable Reflector and platform), its system performance and the current development status.

Earth Explorers are the backbone of the science and research element of European Space Agency (ESA)'s Living Planet Programme, providing an important contribution to the understanding of the Earth system. Following the User Consultation Meeting held in Graz, Austria on 5-6 March 2013, the ESA Program Board has decided implementing Biomass as the 7thEarth Explorer Mission within the frame of the ESA Earth Observation Envelope Programme. This paper will give an overview of the satellite system and its payload. The system technical description presented here is based on the results of the work performed during parallel Phase A system studies by two industrial consortia led by Airbus Space and Defence Ltd. and Thales Alenia Space Italy. Two implementation concepts (respectively A and B) are described and provide viable options capable of meeting the mission requirements.