 The Sentinel-2 mission, developed by the European Space Agency as part of the Copernicus program, is acquiring high spatial resolution optical imagery and has undergone calibration and validation activities after one year in orbit, with measured performances covering both top of atmosphere and bottom of atmosphere products, demonstrating good quality in terms of radiometry and geometry, while providing an overview on next mission steps related to data quality aspects. This article was authored by Farron Gaskin, Catherine Buznak, Olivier Thiepot, and others.