1. Centre d'Etude Spatiale des Rayonnements; Toulouse France
2. NASA Goddard Space Flight Center; Greenbelt Maryland USA
3. Space Sciences Lab.; University of California; Berkeley California USA
4. Department of Physics and Astronomy; Rice University; Houston Texas USA
5. Bartol Research Institute; University of Delaware; Newark Delaware USA
6. NASA Jet Propulsion Lab.; Pasadena California USA