1. The Johns Hopkins University Applied Physics Laboratory Laurel MD USA
2. The Aerospace Corporation El Segundo CA USA
3. Los Alamos National Laboratory Los Alamos NM USA
4. Laboratory for Atmospheric and Space PhysicsUniversity of Colorado Boulder Boulder CO USA
5. Department of Astronomy and PhysicsUniversity of Iowa Iowa City IA USA
6. Space Science CenterUniversity of New Hampshire Durham NH USA
7. Institute of Geophysics and Planetary PhysicsUniversity of California Los Angeles CA USA
8. Now at The Aerospace Corporation El Segundo CA USA