1. Space Science Laboratory; Berkeley California USA
2. Lockheed Martin Adv. Tech. Cent.; Palo Alto California USA
3. Centre d'Etude Spatiale des Rayonnements; Toulouse France
4. Imperial College; London UK
5. Rutherford Laboratory; Oxford UK
6. University of New Hampshire; Durham New Hampshire USA
7. Max-Planck-Institut für extraterrestrische Physik; Garching Germany
8. Tokyo Institute of Technology; Meguro Japan
9. Instituto di Fisica dello Spazio Interplanetario; Rome Italy
10. Max-Planck-Institut für Aeronomie; Katlenburg-Lindau Germany
11. Swedish Institute of Space Physics; Kiruna Sweden