AGU member since 1960. Senior Research Scientist at the Jet Propulsion Laboratory, California Institute of Technology. Principal scientific interest is space plasma physics. B.A. 1954, Cornell Univ.; M.S. 1956, Univ. of Illinois. Employed at Jet Propulsion Laboratory since 1956. Visiting appointments at Cambridge Univ. 1975, Caltech 1986–1987, and Univ. of California, Los Angeles 1990–1991. Investigator on nine space experiments to study the solar wind or comets. Project Scientist for the Comet Rendezvous Asteroid Flyby mission. Past member of numerous NASA committees. Currently member of the National Research Council's Space Studies Board and Chair of its Committee on Solar and Space Physics. Over 100 refereed publications, most in AGU journals. One patent. Honors include NASA Exceptional Scientific Achievement Award 1970 and Fellow of AGU 1989. AGU service as Secretary and President of Solar-Planetary Relationships Section, Associate Editor of J. Geophys. Res. (Space) and Editor-in-Chief of Rev. Geophys. 1989–1992.