GRACE Mission Operations

Abstract

The Gravity Recovery And Climate Experiment (GRACE) is a joint American-German geo-scientific project consisting of two twin satellites flying on a polar low-Earth orbit, with a separation of approximately 220 km. The main scientific goal is to obtain high-precision data for both the static and time-varying gravitational fields of Earth. GRACE was launched by a ROCKOT launcher from Plesetsk, Russia, on March 17th 2002. The mission operations are carried out by the German Space Operations Centre (GSOC) in Oberpaffenhofen, Germany. After six months in-orbit, the GRACE mission is approaching the end of its commissioning phase and is gradually transitioning into the observational phase, which is planned to last for the next 5 years. The LEOP and commissioning phases involved a significant amount of work by all participating teams. A number of anomalies and contingencies have prolonged these mission phases, which were originally planned to last only 42 days. The presentation describes some of the operational experiences from these exciting and demanding first six-months in-orbit. It includes topics on operations planning, with particular emphasis on dealing with two satellites, an overview of the multi-mission environment at GSOC and some aspects of working on an international project together with teams situated in the U.S. and in other areas of Germany.