On 15 September, FLEX and Sentinel-3C launched from French Guiana aboard a Vega-C rocket. Both reached orbit and established contact with mission control. [1]

FLEX will measure the faint fluorescence plants emit during photosynthesis. Sentinel-3C will observe oceans, land, ice and the atmosphere: different tools for understanding the same planet. [2]

The successful launch begins checks on the satellites and their instruments. The expected scientific benefits still depend on these steps: they are not findings already delivered. [1]