“Revolutionary” is a word you hear often when people talk about the GRACE mission. Since the twin satellites of the NASA/German Gravity Recovery and Climate Experiment (GRACE) launched on March 17, 2002, their data have transformed scientists’ view of how water moves and is stored around the planet. “GRACE enabled tracking the movement of water via its mass, a field which was not available in spaceborne remote sensing and which opened new options to monitor and quantify climate change,” said Reinhard Hüttl, the Chairman of the Board and Scientific Executive Director of the Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences.