GRACE

Abstract

The GRACE (Gravity Recovery And Climate Experiment) satellite mission is in general to a large extent based on hardware and experience of the German CHAMP (CHAllenging Minisatellite Payload) satellite mission with the addition of a second satellite plus an ultra-precise intersatellite K-band link. Since March 2002 the two identical spacecrafts are flying on the same orbit 220 (±50) km apart. The two satellites weigh 485 kg each and were launched to an orbit with an initial altitude of 500 km. After a brief mission overview the main scientific results are presented as well as operational aspects dedicated to the GRACE mission. Here two aspects are addressed more in detail from the flight dynamics point of view, the formation keeping and the swap of the satellite position.