Laser interferometry for future satellite gravity missions

Benjamin Sheard, Marina Dehne, Christoph Mahrdt, Gerhard Heinzel and Karsten Danzmann
Albert-Einstein-Institut Hannover, Callinstraße 38, 30167 Hannover, Germany

The application of laser interferometry for use in satellite gravimetry using satellite-to-satellite tracking will be discussed. At present we are focusing on a `GRACE-like' configuration with two satellites where the inter-spacecraft distance is measured using an on-axis heterodyne interferometer with an active transponder. The feasibility of an off-axis interferometer design and operation without drag-free attitude control is also being investigated. The status of a laboratory demonstrator of the interferometer concepts will be given.