Prolonging the Grace Mission despite degraded Batteries

The two Grace satellites were successfully launched on March 17, 2002 by a Russian Rockot launcher. GRACE not only was the first dual-satellite mission operated by GSOC, but it also was the first formation-flying occurring at an altitude below 500 km. The mission is extremely successful from a scientific point of view and the originally envisaged mission duration of 5 years has more than doubled by now. A follow-on mission is planned by the same partners for 2016 and JPL projects a new generation in the twenties, so there is a strong incentive to prolong GRACE and try to bridge the gap.