Dr. Edward C. Stone (1936-2024)

Edward C. Stone was an internationally known physicist who served as project scientist for the Voyager program from 1972 to 2022. As a graduate student at the University Chicago, he was inspired to enter the fields of planetary science and space exploration by the launch of Sputnik in 1957.

Stone was born in Knoxville, Iowa, on January 23, 1936. After receiving his undergraduate education at Iowa's Burlington Junior College, Stone attended the University of Chicago where he earned his master's degree and Ph.D. in physics. He then joined the staff of Caltech as a researcher, and became a full faculty member in 1967. In 1972, he became the Voyager project scientist.

Since the launch of the two Voyager spacecraft in 1977, Stone had coordinated the efforts of 11 teams of scientists in their investigations of Jupiter, Saturn, Uranus and Neptune. He also became nationally known as the JPL public spokesman during the planetary flybys, explaining the Voyager's scientific discoveries to the public. Highlights of his decade of leadership included Galileo's five-year orbital mission to Jupiter, the launch of Cassini to Saturn, the launch of Mars Global Surveyor and a new generation of Earth science satellites such as TOPEX/Poseidon and SeaWinds, and the successful Mars Pathfinder landing in 1997. Stone retired from JPL in April of 2001 and subsequently worked full-time at Caltech, teaching and doing research.

In the late 1980s through the 1990s, Stone served as vice chairman and chairman of the Board of Directors of the California Association for Research in Astronomy, which is responsible for building and operating the W.M. Keck Observatory with its two ten-meter telescopes on Mauna Kea, Hawaii. He also served as Director of the W.M. Keck Foundation.

In addition to becoming a member of the National Academy of Sciences in 1984, Stone was recognized with numerous awards, among them the NASA Distinguished Service Medal and National Medal of Science.

Publications

Communications Technologies for Space Exploration, Stone, E. C., Proceedings of the IEEE, Vol. 87, No. 6 pp. 1044-6, 1999.
Constraints on the Time Delay between Nucleosynthesis and Cosmic-Ray Acceleration from Observations of Sup 59/Ni and Sup 59/Co, Wiedenbeck, M. E., W. R. Binns, E. R. Christian, A. C. Cummings, B. L. Dougherty, P. L. Hink, J. Klarmann, R. A. Leske, M. Lijowski, R. A. Mewaldt, E. C. Stone, M. R. Thayer, T. T. Von Rosenvinge, and N. E. Yanasak, Astrophysical Journal, Letters, Vol. 523, No. 1 pp. L61-4, 1999.
The Cosmic-Ray Isotope Spectrometer for the Advanced Composition Explorer, Stone, E. C., C. M. S. Cohen, W. R. Cook, A. C. Cummings, B. Gauld, B. Kecman, R. A. Leske, R. A. Mewaldt, M. R. Thayer, and B. L. Dougherty, The Advanced Composition Explorer mission; Proceedings of the ASE Science Workshop, California Inst. of Technology, Pasadena, Jan. 7-9, 1997.; Space Sciences Reviews, Vol. 86, Nos. 1-4, 1998, p. 285-356.
Effects of Absorption by Io on Composition of Energetic Heavy Ions, Garrard, T. L., E. C. Stone, and N. Murphy, Science, Vol. 274, No. 5286 pp. 393-394, 1996.
Energetic Particle Signatures of Satellites and Rings in Neptune's Magnetosphere, Selesnick, R. S. and E. C. Stone, (Planetary studies; Proceedings of Symposium 4 and the Topical Meeting of the Interdisciplinary Scientific Commission B /Meetings B7 and B8/ of the COSPAR 28th Plenary Meeting, The Hague, Netherlands, June 25-July 6, 1990. A92-45276 19-91) Advances in Space Research, Vol. 12, No. 11, p. 71-79, Nov. 1992.
Estimate of the Distance to the Solar Wind Termination Shock from Gradients of Anomalous Cosmic Ray Oxygen, Cummings, A. C., E. C Stone, and W. R. Webber, Journal of Geophysical Research, Vol. 98, No. A9 p. 15,165-15,168. Sept. 1, 1993.
Event-to-Event Variations in the Isotopic Composition of Neon in Solar Energetic Particle Events, Leske, R. A., R. A. Mewaldt, C. M. S. Cohen, A. C. Cummings, E. C. Stone, M. E. Wiedenbeck, E. R.Christian, and T. T. Von Rosenvinge, Geophysical Research Letters, Vol. 26, No. 17 pp. 2693-2696, 1999.
Face to Face - with Edward Stone, Benson, J. and E. C. Stone, Aerospace America, Vol. 30, No. 7 pp. 6-8, 1992.
Inferred Charge States of High Energy Solar Particles from the Solar Isotope Spectrometer on Ace, Cohen, C. M. S., A. C. Cummings, R. A. Leske, R. A. Mewaldt, E. C.Stone, B. L Dougherty, M. E. Wiedenbeck, E. R. Christian, and T. T. Von Rosenvinge, Geophysical Research Letters, Vol. 26, No. 2, pp. 149-152, 1999.
Io Encounters Past and Present - a Heavy Ion Comparison, Cohen, C. M. S., Garrard, T. L., E. C. Stone, J. F. Cooper, N. Murphy, and N. Gehrels, Journal of Geophysical Research, Vol. 105, No. A4, p. 7775-7782, 1 Apr. 2000.
Mars and the Search for Life Elsewhere - Innovations in the Third Era of Space Exploration, Stone, E. C., AIAA Paper 99-0002, AIAA Student Journal, Vol. 38, No. 1, p. 4-7, Spring 2000.
New Observations of Heavy-Ion-Rich Solar Particle Events from Ace, Cohen, C. M. S., R. A. Mewaldt, R. A. Leske, A. C. Cummings, E. C. Stone, M. E. Wiedenbeck, E. R. Christian, E. R. and T. T. Von Rosenvinge, Geophysical Research Letters, Vol. 26, No. 17 pp. 2697-2700, 1999.
Particle Acceleration and Sources in the November 1997 Solar Energetic Particle Events, Mason, G. M., C. M. S. Cohen, A. C. Cummings, J. R. Dwyer, R. E. Gold, S. M. Krimigis, R. A. Leske, J. E. Mazur, R. A. Mewaldt, E. Mobius, M. Popecki, E. C. Stone, T. T. Von Rosenvinge, and M. E. Wiedenbeck, Geophysical Research Letters, Vol. 26, No. 2 pp. 141-144, 1999.
Sampex Studies of Anomalous Cosmic Rays Using the Geomagnetic Field, Mewaldt, R. A., J. R. Cummings, A. C. Cummings, R. A. Leske, E. C. Stone, and T. T. Von Rosenvinge, presented at International Solar Wind 8 Conference Jun. 30, 1995.
The Solar Isotope Spectrometer for the Advanced Composition Explorer, Stone, E. C., C. M. S. Cohen, W. R. Cook, A. C. Cummings, B. Gauld, B. Kecman, R. A. Leske, R. A. Mewaldt, M. R. Thayer, and B. L. Dougherty, The Advanced Composition Explorer mission; Proceedings of the ASE Science Workshop, California Inst. of Technology, Pasadena, Jan. 7-9, 1997.; Space Sciences Reviews, Vol. 86, Nos. 1-4, p. 357-408, 1998.
Two-Dimensional Position-Sensitive Silicon Detectors for the Ace Solar Ope Spectrometer, Wiedenbeck, M. E., E. R. Christian, W. R. Cook, III, A. C. Cummings, B. L. Dougherty, R. A. Leske, R. A. Mewaldt, E. C. Stone, and T. T. Rosenvinge, Proceedings of SPIE - The International Society for Optical Engineering, Vol. 2806 pp. 176-187, 1996.
Unusual Isotopic Composition of Solar Energetic Particles Observed in the November 6, 1997 Event, Leske, R. A., C. M. S. Cohen, A. C. Cummings, R. A. Mewaldt, E. C. Stone, B. L. Dougherty, M. E. Wiedenbeck, E. R. Christian, and T. T. Von Rosenvinge, Geophysical Research Letters, Vol. 26, No. 2 pp. 153-156, 1999.
The Voyager Encounter with Neptune, Stone, E. C. and E. D. Miner, Journal of Geophysical Research Supplement, Vol. 96, p. 18,903-18,906, Oct. 30, 1991.
The Voyager Mission Through the Jupiter Encounters, Stone, E. C., Journal of Geophysical Research, Vol. 86, No. A10, pp. 8123-8124, September 30, 1981.
Voyager 1 Encounter with the Jovian System, Stone, E. C. and A. L. Lane, Science, Vol. 204, pp. 945-948, June 1, 1979

In 1972, Ed Stone became the Voyager Project Scientist. Twenty years later, both Voyager spacecraft were still operating, and this photo was taken in front of a full-scale model of the spacecraft, after Stone had been Director of JPL for about one year.

Stone earned the National Medal of Science in March 1992. A proud colleague of Stone's captured the momentous event on whiteboard with markers.

Dr. Stone circulated through the crowd at a JPL Open House, meeting employees and visitors. Of note, immediately to the right of Stone, in the center of the picture, is Apollo Milton Olin (also known as A.M.O., or "Amo") Smith. Smith was an associate of Frank Malina and involved with rocket testing in the early days of JPL.