Beyond Gravity Technologies Help Enable ESA’s FLEX Satellite to Track Global Vegetation Health

How do plants respond to environmental pressures, such as drought, heat, and climate change? A new European satellite called FLEX will map vegetation fluorescence from space and provide scientists with essential data to answer these questions. The European Space Agency’s (ESA) Fluorescence Explorer (FLEX) satellite has been launched today, 15 September, 3:21 CEST, alongside the Copernicus Sentinel-3C satellite of the European Union. Both satellites, developed by Thales Alenia Space as prime contractor, have been launched together aboard a European Vega-C launch vehicle from the European spaceport in French Guiana. Beyond Gravity has contributed key technologies to the two satellites as well as the launch vehicle. “We are proud to contribute technologies across the mission, from platform architecture and structures to onboard electronics, thermal protection and navigation. Our extensive involvement reflects Beyond Gravity’s position as a trusted partner for complex Earth observation programs and highlights the strength of European industrial cooperation”, says Dr. Barbara Frei-Spreiter, CEO of Beyond Gravity, a leading global supplier to the space industry headquartered in Zurich (Switzerland). 

Beyond Gravity in charge of mechanical and thermal architecture

For FLEX, Beyond Gravity served as Design Authority for the mechanical and thermal architecture of the satellite platform and supplied several critical subsystems, including the satellite structure, onboard computer, thermal insulation, navigation receiver and X-band helix antenna. The company also provided the payload fairing and onboard computer for the Vega-C launcher.

As Design Authority for the satellite platform’s mechanical and thermal design, Beyond Gravity was responsible for ensuring the structural and thermal performance required to support the highly sensitive instrument of FLEX throughout launch and operations in orbit. FLEX is designed for a nominal mission lifetime of 3.5 years in orbit and will orbit Earth at an altitude of about 800 kilometers. 

Central computer controls the satellites

Beyond Gravity delivered the central control computer for the FLEX satellite and the Sentinel-3C satellite. The computer monitors and controls the status of the satellite. It ensures that the satellite is fully functional, including also pointing in the right direction to allow the payload on board to perform its measurements. It also handles all the communication between the satellite and ground control.  

Thermal insulation

Beyond Gravity supplied the thermal protection for the FLEX plant health satellite. The insulation consists of several layers of ultra-thin, specialized plastic films. The multilayer insulation protects the satellite from the extreme cold and heat in space. Also Sentinel-3C is wrapped in thermal insulation from the company. Nearly every European ESA satellite is protected by thermal insulation from Beyond Gravity. 

Satellite structure

Beyond Gravity designed, built, and tested the lightweight structure of the FLEX satellite. The structure consists of aluminum honeycomb panels and various tertiary structural components. The total mass of the ESA FLEX satellite is about 400 kilograms, whereas the satellite structure developed by Beyond Gravity weighs only 80 kilograms. This means the structure can carry more than four times its own weight. 

Precise position determination

The satellites FLEX and Sentinel-3C both determine their precise position in orbit with navigation receivers from Beyond Gravity. The receivers can process both US GPS signals as well as navigation signals from Galileo, the EU Global Navigation Satellite System. The more accurate the positioning, the more accurate the data provided by the satellite. Currently, Beyond Gravity’s navigation receivers determine the position of around 30 satellites in space. 

Various antennas

Beyond Gravity also contributed the X-band helix antenna to FLEX. The X-band helix antenna combines superior performance, high antenna gain with smaller dimensions and lower mass. All FLEX science data are transmitted via the X-band antenna from Beyond Gravity from orbit to earth. For Sentinel-3C, the company provided telecommands and telemetry antennas.

Fairing and computer for Vega-C

Beyond Gravity produced the Vega-C On Board Computer. The computer controlled the rocket during launch and is part of the Vega Avionics System. The payload fairing from Beyond Gravity protected the two satellites from extreme thermal, acoustic, and mechanical stresses during launch. This nine-meter-long, two-piece structure is made of carbon-fiber-reinforced composite material and features an automatic pyrotechnic separation system. This system ensures the fairing is jettisoned precisely in the upper atmosphere. Its aerodynamic shape supports efficient flight performance.

Vega-C: 35 meters tall launcher

Europe’s Vega-C rocket, designed developed and operated by Avio, can launch satellites up to 2300 kg into space, such as small scientific and Earth observation satellites. The Vega-C is 35 meters tall and weighs more than 200 tons on the launch pad. Vega-C is the evolution of the Vega family of rockets and delivers increased performance, greater payload volume and improved competitiveness.

FLEX: insights into vegetation stress

The FLEX mission will collect data on a phenomenon that is invisible to the human eye: the faint fluorescence that plants emit during photosynthesis. From orbit, FLEX will detect and measure this incredibly weak signal. Since fluorescence varies with plant health and environmental conditions, these measurements will give scientists new insights into photosynthetic activity and vegetation stress on a global scale. FLEX will produce global maps of vegetation fluorescence. This will offer a new way to study how plants interact with the atmosphere and how carbon and water move through Earth’s ecosystems.

Sentinel-3

Copernicus Sentinel-3C is the third satellite in the Sentinel-3 series. Like its two predecessors already in orbit, it carries a suite of advanced instruments that systematically measure Earth’s oceans, land, ice and atmosphere. These observations support the monitoring and understanding of large-scale processes and dynamics across our planet, while providing essential near-real-time information for ocean and weather forecasting.

Image

Image 1: The plant health observing satellite FLEX uses key technology from Beyond Gravity. © ESA.

Image 2: Observing the state of global vegetation: FLEX satellite from ESA. © ESA/ATG Medialab.

Image 3: The Vega-C rocket uses computer and payload fairing from Beyond Gravity. © ESA.

Image 4: The environmental satellite Sentinel-3C is protected by thermal insulation from Beyond Gravity. © ESA/ATG Medialab. 

About Beyond Gravity

Beyond Gravity, headquartered in Zurich, Switzerland, is the first space company to combine a startup mindset, agility, speed and innovation with decades of experience and proven quality. Approximately 1900 employees at 12 locations in six countries (Switzerland, Sweden, Austria, USA, Finland and Portugal) develop and produce solutions for satellites and launch vehicles with the goal of advancing humankind and enabling the exploration of the world and beyond. Beyond Gravity is the preferred supplier of structures for all types of launch vehicles and a leading provider of selected satellite products and constellation solutions in the New Space sector. In 2025, the company generated a revenue of around CHF 402 million. More information at: www.beyondgravity.com