Vega-C rocket launches FLEX and Sentinel-3C satellites to track climate and plant health

Launch from Kourou

An Italian-operated Vega-C rocket lifted off from the Guiana Space Centre in Kourou, French Guiana, on Monday, 14 September 2026 at 22:21 local time (03:21 Tuesday in Central European time). Carrying a combined payload of 1.5 tonnes, the launcher placed two European Earth observation satellites into sun-synchronous orbit over the course of nearly two hours. Flight controllers confirmed nominal propulsion 14 seconds after liftoff as the vehicle ascended through partly veiled night skies. The tandem launch relied on a new adapter called Vespa, manufactured in Italy by Avio, which held both spacecraft inside the rocket fairing. Sentinel-3C separated first from its position atop Vespa, followed by the FLEX satellite approximately one hour later. Telemetry signals received by the European Space Operations Centre (ESOC) in Germany confirmed that both spacecraft entered their intended orbits.

Tracking vegetation fluorescence

The FLuorescence EXplorer (FLEX) satellite, with a launch mass of approximately 400 kilograms, was developed by Thales Alenia Space for the European Space Agency (ESA). Manufactured at the company's facility in Cannes, France, FLEX uses an imaging spectrometer to observe vegetation health by measuring red fluorescence emitted during photosynthesis. The mechanism captures the process through which flora absorbs carbon dioxide and water to produce growth energy and release oxygen. By measuring this faint optical glow from an altitude of 800 kilometres, researchers intend to assess plant stress caused by heatwaves, drought sequences, and varying soil qualities across global biomes.

Dominique Gilliéron, head of the Earth observation projects department at ESA, noted the precision required to detect the phenomenon from space.

It is a technological feat, because this photosynthesis signal is extremely weak.

Expanding the Copernicus network

Launched alongside FLEX was Sentinel-3C, a 1,140-kilogram satellite belonging to the Copernicus Earth observation programme managed by the European Commission and ESA. Positioned in a low Earth orbit at an altitude of 814 kilometres, the satellite has a planned operational lifespan of 7.5 years and will operate in tandem with Sentinel-3B. The spacecraft carries four specialized instruments delivering near real-time data on sea surface temperature, ocean colour, wave heights, and marine currents. On land, its sensors track soil temperature, fire detection, vegetation conditions, and water quality across rivers and lakes to assist agricultural planning and food security management.

Simonetta Cheli, director of Earth observation programmes at ESA, addressed the international scope of the mission following orbital confirmation.

Today's launch represents the culmination of years of scientific innovation, engineering excellence and international cooperation.

European launch operations in 2026

The flight was the second mission of 2026 for the Vega-C system, which is overseen jointly by ESA and prime contractor Avio. The mission adds to a series of European space operations in 2026, which includes four successful Ariane 6 launches and the Spectrum flight conducted from Norway by German startup Isar Aerospace. Thales Alenia Space, which built both satellite payloads, is a joint venture owned 67% by French company Thales and 33% by Italian aerospace firm Leonardo. Both satellites will now undergo on-orbit checkout before delivering environmental data to European and international research teams.