The European Space Agency (ESA) successfully launched its Copernicus Sentinel-3B satellite on April 25 from Russia, where it joined its identical twin Sentinel-3A in orbit. The two satellites each carry a range of technologies to monitor the Earths land mass, oceans and atmosphere. The pairing of satellites will increase coverage and data delivery for the European Unions Copernicus environment program. Sentinel-3B sent its first signals to the Kiruna station in Sweden just 92 minutes after liftoff. Data links were quickly established by teams at ESAs operations center in Darmstadt, Germany, allowing them to assume control of the satellite. The mission is expected to begin routine operations after five months. Jan Wörner, director general, ESA, said, This is the seventh launch of a Sentinel satellite in the last four years. It is a clear demonstration of what European cooperation can achieve and it is another piece to operating the largest Earth observation program in the world, together with our partners from the European Commission and Eumetsat. Josef Aschbacher, director of Earth observation programs, ESA, said, With Sentinel-3B, Europe has put the first constellation of Sentinel missions into orbit this is no small job and has required strong support by all involved. It allows us to get a very detailed picture of our planet on a daily basis and provides crucial information for policy makers. It also offers lots of opportunities for commercial companies to develop new innovative services. And, the free and open data policy allows every citizen to have updates for their own use. Copernicus relies on the Sentinels and contributing missions to provide data for monitoring the environment and for supporting civil security activities. Sentinel-3 carries a series of cutting-edge sensors to do just that. Over oceans, it measures the temperature, color and height of the sea surface as well as the thickness of sea ice. These measurements are used, for example, to monitor changes in Earths climate and for more hands-on applications such as marine pollution. Over land, the satellites monitor wildfires, land use, vegetation health and measures the height of rivers and lakes. Data from the Copernicus program is used worldwide and is free of charge.