Watch the full replay of the launch of ESA’s state-of-the-art FLEX Earth Explorer satellite and the Copernicus Sentinel-3C satellite. Both were launched together aboard a Vega-C rocket from Europe’s Spaceport in French Guiana, marking a new milestone in Europe’s Earth Observation Programmes. Flight VV30 lifted off on 15 September at 03:21 (14 September at 22:21 local time).  

FLEX is designed to reveal a phenomenon invisible to the human eye: the faint fluorescence emitted by plants as they photosynthesise. Equipped with a Fluorescence Imaging Spectrometer, FLEX will detect and measure this incredibly weak signal from orbit. Because the fluorescence varies with plant health and environmental conditions, the measurements will provide scientists with new information about photosynthetic activity and vegetation stress on a global scale. 

Sentinel-3C is the third in the Sentinel-3 series.  Carrying a suite of cutting-edge instruments, Copernicus Sentinel-3C will continue the mission’s task of measuring systematically Earth’s oceans, land, ice and atmosphere to monitor and understand large-scale global dynamics. The mission also provides essential information in near-real time for ocean and weather forecasting.  

Europe’s Vega-C rocket can launch 2300 kg into space, such as small scientific and Earth observation spacecraft. At 35 m tall, Vega-C weighs 210 tonnes on the launch pad and reaches orbit with three solid-propellant-powered stages before the fourth liquid-propellant stage takes over for precise placement of satellites into their desired orbit around Earth. This flight was a first dual launch for Vega-C, using a secondary payload adapter called Vespa. Sentinel-3C was placed on top of Vespa inside the main fairing and once deployed the Vespa adapter opened to reveal FLEX for its injection into orbit.