A German minisatellite mission to study global long- to medium-wavelength recovery of the static and time-variable Earth gravity field from orbit perturbation, for use in solid-Earth and geodesy research and in studying ocean currents and climate. The satellite was launched on 15 July 2000, but after 3718 days of supplying data it burnt up on 19 September 2010 over the Sea of Okhotsk.