1. NASA Goddard Space Flight Center; Greenbelt; Maryland; USA
2. Los Alamos National Laboratory; New Mexico; USA
3. Engineering Physics; University of Virginia; Charlottesville; Virginia; USA
4. Mullard Space Science Laboratory; University College London; Dorking; UK
5. Southwest Research Institute; San Antonio; Texas; USA
6. Department of Physics and Astronomy; University of Montana; Missoula; Montana; USA
7. Blackett Laboratory; Imperial College; London; UK
8. Centre d'Etude Spatiale des Rayonnements; Toulouse; France