With the first Copernicus Sentinel-2 satellite in orbit since 2015 and the second since 2017, engineers are busy preparing the mission’s follow-on pair to eventually pick up the baton to supply images for a myriad of applications from food security to monitoring the decline of Earth’s ice. Slated for launch at the beginning of 2024, Sentinel-2C has just started a punishing five-month testing programme to ensure that it is fit for its life in space.