Edward C. Stone

Edward C. Stone
Stone in 1981
7th Director of the Jet Propulsion Laboratory
In office
January 1, 1991  April 30, 2001
Preceded byLew Allen
Succeeded byCharles Elachi
Personal details
Born
Edward Carroll Stone Jr.

January 23, 1936 (1936-01-23)
Knoxville, Iowa, U.S.
DiedJune 9, 2024 (2024-06-10) (aged 88)
Pasadena, California, U.S.
Known forJPL director and Voyager scientist
Alma materUniversity of Chicago (MS, PhD)
Scientific career
FieldsSpace physics
Thesis Low energy cosmic-ray protons  (1964)
Doctoral advisorJohn A. Simpson
Doctoral studentsNeil Gehrels
Jamie Sue Rankin

Edward Carroll Stone Jr. (January 23, 1936 – June 9, 2024) was an American space physicist, professor of physics at the California Institute of Technology, and director of the NASA Jet Propulsion Laboratory (JPL) from 1991 to 2001. He is best known as the project scientist of the Voyager program, which sent two spacecraft to the outer Solar System's giant planets and became the first spacecraft to enter interstellar space.

Stone led the Voyager mission for 50 years, from 1972 until his retirement in 2022, overseeing the spacecraft's encounters with Jupiter (1979), Saturn (1980-1981), Uranus (1986), and Neptune (1989). Under his leadership, the mission discovered active volcanism on Jupiter's moon Io, new moons and ring systems. The Voyagers continued beyond the planets to cross the heliopause and enter the interstellar medium, with Voyager 1 becoming the first spacecraft to leave the Solar System in 2012, followed by Voyager 2 in 2018. The Voyager mission became the longest-running NASA mission, with Stone being its face and advocate.

As JPL director, Stone oversaw the successful launches of Mars Pathfinder with the first Mars rover Sojourner, Mars Global Surveyor, Cassini–Huygens, and other missions during NASA's "faster, better, cheaper" era. Throughout his career, he served as principal investigator on nine NASA spacecraft missions, including SAMPEX, the Advanced Composition Explorer, and scientific instruments on the Galileo and STEREO missions.

Stone's contributions to space science earned him the National Medal of Science (1991), the NASA Distinguished Public Service Medal (2013), and the Shaw Prize in Astronomy (2019). He was elected to the National Academy of Sciences in 1984 and served key roles in establishing major astronomical facilities, including overseeing the creation of the Laser Interferometer Gravitational-Wave Observatory (LIGO) during his tenure as chair of Caltech's Division of Physics, Mathematics, and Astronomy, and supervising the construction of the W. M. Keck Observatory.