ESA’s New Biomass Launched to Map Forests’ Carbon

On Tuesday, April 29, 2025, at 09:15 UTC, Arianespace successfully launched ESA’s Earth Explorer Biomass satellite aboard a Vega-C rocket from Europe’s Spaceport in French Guiana. Designated VV26, the mission marked the fourth flight of Vega-C and the 353rd launch conducted by Arianespace.

LIFTOFF of our Biomass mission on a Vega-C rocket from Europe's Spaceport in French Guiana! pic.twitter.com/ufvuCf10qc
— European Space Agency (@esa) April 29, 2025

The rocket’s P120C first stage, equipped with 143.6 tonnes of solid propellant and delivering 4500 kN of thrust, powered a strong and stable ascent. Vega-C then continued its sequence through the subsequent stages, culminating with the cutoff of the fourth stage and initiating the payload separation process.

Spacecraft separation occurred 57 minutes after launch, at 10:12 UTC, successfully inserting Biomass into a Sun-synchronous orbit at an altitude of approximately 666 kilometers. The first signal acquisition via ESA’s ESOC ground station was confirmed about 14 minutes later, verifying the satellite’s health and positioning.

Now in orbit, Biomass is set to embark on a pioneering mission to deliver unprecedented data on global forest biomass. This data will offer critical insights into changes in Earth’s forests and significantly enhance our understanding of the planet’s carbon cycle.

The first P-band SAR in space to map the forests’ carbon

Manufactured by Airbus Defence and Space, Biomass is a three-axis stabilized satellite platform measuring a whopping 10 meters tall, 12 meters wide, and 20 meters long once its large deployable reflector is unfolded. Weighing 1170 kilograms at launch, the spacecraft carries the first P-band synthetic aperture radar (SAR) ever flown in space, operating at 435 MHz.

Its primary instrument, a fully polarimetric radar with a 12-meter circular reflector, will provide unprecedented observations of global forest structure and biomass from its Sun-synchronous orbit at 666 kilometers altitude. The Biomass mission is designed to map the amount of carbon stored in Earth’s forests and monitor changes over time, exploiting the P-band’s long wavelength (about 70 centimeters), which can penetrate forest canopies and interact with trunks and branches.

*The ESA Biomass satellite at Airbus Defence and Space factory in Stevenage, UK. Credits: Airbus Defence and Space, ESA*

Biomass will deliver hectare-scale measurements of above-ground biomass (AGB) with an accuracy of 20 percent, monitor deforestation and regrowth, especially in tropical regions, and help track changes in forest carbon fluxes.

In addition to its core biomass objectives, Biomass will explore subsurface geology in deserts, investigate the ice structure of glaciers and ice sheets, and map forest floors.

During its first year, the mission includes two main scientific phases: polarimetric interferometry (PolInSAR) and a tomographic SAR (TomoSAR) phase, which will provide 2D and 3D data products. Designed for a five-year lifespan, Biomass will witness at least eight growth cycles in forests worldwide, offering key data to support climate science, biodiversity studies, and sustainable forest management.

*ESA’s Biomass Earth Explorer satellite with its 12-m diameter radar antenna. Credits: ESA*

Vega-C to secure Europe’s access to space

The VV26 launch marks the fourth flight of the Vega-C rocket, following a mixed but promising operational history. Since its maiden mission in July 2022, Vega-C has completed three flights:

VV21, a successful debut carrying LARES 2 and six CubeSats;
VV22, a failure caused by an anomaly in the Zefiro 40 second stage that resulted in the loss of two Pléiades Neo satellites;
VV25, the successful return to flight with the launch carrying Sentinel-1C in December 2024.

With two successful missions out of three before VV26, Vega-C was steadily rebuilding confidence ahead of this latest success.

Vega-C Mission VV22 Lifting Off the Pad. Credits: ESA-Arianespace-CNES-Optique video du CSG-JM Guillon — *Vega-C Mission VV22 Lifting Off the Pad. Credits: ESA/Arianespace/CNES*

In 2025, Vega-C operations will undergo a major transition. Avio, the Italian aerospace company and the launcher’s prime contractor, will take over the commercial operations of Vega-C flights from Arianespace. This move aims to streamline Avio’s service offerings and reinforce Europe’s independent access to space at a time of growing strategic importance.

The launcher’s schedule remains busy, with four missions planned for 2025, including the upcoming VV27 in July. That mission will carry five Earth observation satellites into Sun-synchronous orbit: the four CO3D satellites, developed by Airbus Defence and Space and CNES to generate high-resolution 3D maps, and the MicroCarb satellite, tasked with measuring atmospheric carbon dioxide concentrations.

Five more launches are scheduled for 2026, with key missions such as ClearSpace-1, Sentinel-3C, and Sentinel CO2M-A leading the manifest. With a reinforced operational model and a full pipeline of missions, Vega-C is poised to become a cornerstone of Europe’s future in space, ensuring reliable access for scientific, environmental, and strategic needs.

^{*Cover image credits: ESA}