1. Institut d'Astrophysique Spatiale, Orsay, France.
2. European Space Research and Technology Centre, Noordwijk, Netherlands.
3. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA, deceased.
4. Institute for Geophysics and Extraterrestrial Physics, TU-Braunschweig, Germany.
5. DLR RB-MUSC, Cologne, Germany.
6. Politecnico di Milano, Milan, Italy.
7. Max Planck Institute for Solar System Research, Göttingen, Germany.
8. University of Mainz, Mainz, Germany.
9. Institut de Planétologie et d'Astrophysique de Grenoble, Grenoble, France.
10. DLR, Institute of Planetary Research, Berlin, Germany.
11. Open University, Milton Keynes, UK.