Ariane 6 on flight designated VA265. Credit: ESA-CNES-ARIANESPACE/Optique vidéo du CSG–P. Piron"> Sentinel-1D was launched on Europe’s heavy-lift rocket Ariane 6 on flight designated VA265. Credit: ESA-CNES-ARIANESPACE/Optique vidéo du CSG–P. Piron

The Copernicus Sentinel-1D satellite, launched last November , is now fully operational after successfully completing its critical in-orbit commissioning phase. With all four Sentinel-1 satellites having now been deployed, this achievement marks a major milestone for this flagship radar mission—a journey that began more than a decade ago and that has helped pave the way for the future of Earth observation.

When Sentinel-1A—the first of this generation—launched in 2014, it marked more than the start of a single mission; it signaled the beginning of Copernicus, the Earth observation component of the European Union's space program.

Its success demonstrated that Europe could deliver consistent, high-quality Earth observation data for the Copernicus Services, and…