Sentinel-3A will be launched on a Rockot from the Plesetsk cosmodrome in Russia. It separates from the Breeze upper stage about 20 minutes after launch. Carrying a suite of cutting-edge instruments, the Copernicus Sentinel-3A satellite will measure systematically Earth’s oceans, land, ice and atmosphere to monitor and understand large-scale global dynamics. It will provide essential information in near-real time for ocean and weather forecasting.