1. Center for Space Physics, College of Engineering, Boston University, Boston, Massachusetts 02215, USA
2. NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
3. The Aerospace Corporation, Los Angeles, California 90245, USA
4. Drexel University, Philadelphia, Pennsylvania 19104, USA
5. The Henry A. Rowland Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21210, USA
6. Space Exploration Sector, Johns Hopkins Applied Physics Laboratory, Laurel, Maryland 20723, USA
7. Merrimack College, North Andover, Massachusetts 01845, USA