The Earth Explorer FLEX satellite and the Copernicus Sentinel-3C satellite are launched together aboard a Vega-C rocket from Europe’s Spaceport in French Guiana.

A new launch adapter called Vespa allows both satellites to be stacked inside the Vega-C fairing for launch. Positioned on top of Vespa, Sentinel-3C is injected into orbit first, followed by FLEX approximately one hour later.

The animation shows the separation of the Sentinel-3C and FLEX satellites from the fairing and their solar panel deployments.

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 satellite in the Copernicus Sentinel-3 series. Like its two older siblings in orbit, Sentinel-3C carries a suite of cutting-edge instruments that measure systematically Earth’s oceans, land, ice and atmosphere to monitor and understand large-scale global dynamics. It provides essential information in near-real time for ocean and weather forecasting.

Europe’s Vega-C rocket is an evolution of the Vega family, offering increased performance, greater payload capacity and improved competitiveness. With the capability to carry up to 3300 kg into orbit, Vega-C is well suited to launching scientific and Earth observation satellites into space.