Edward C. Stone

Caltech Stone moved to Caltech to work on space physics with Rochus Eugen Vogt in 1964, and helped him establish the Space Radiation Laboratory. and was chair of the Division of Physics, Mathematics, and Astronomy from 1983 to 1988; He also served on the board of the California Association for Research in Astronomy (CARA) for nearly 25 years, and oversaw the construction of the W. M. Keck Observatory.

In 1972, Stone became the project scientist for the Voyager program that sent two space probes to the giant planets in the outer Solar System. according to Schurmeier, Stone was proposed as the project scientist by Rochus Vogt, who was involved in the Grand Tour mission planning from the start. Stone himself was reluctant at first: as a scientist, he didn't want to sacrifice a lot of time for administrative work. Stone was also the principal investigator for the Cosmic Ray Subsystem experiment on both Voyager spacecraft.

Stone supervised the work of 11 teams of about 200 scientists; he organized "the clique-like teams" and work groups for key points of interest, "moons, rings, atmosphere and magnetosphere". Stone had the final word on observation target selection, instrument usage, and the spacecraft trajectories. According to the Voyager project manager Norman Haynes, Stone "revolutionized the world of project science".

Stephen P. Synnott recounted how Stone let him name a moon of Jupiter that he discovered on Voyager photos in 1980, saying "it looks like you've found yourself a moon" after checking the calculations. Synnott chose Thebe from a list of names suggested by the IAU.

Stone was the main advocate and salesman of the Voyagers. After the last planetary encounter he was able to receive funding for an extended mission, the Voyager Interstellar Mission. The Voyagers became the only spacecraft that left Solar System into interstellar space.

Jamie Sue Rankin became Stone's last PhD student. Her thesis was on the Voyagers' interstellar space data; she graduated in 2018 and became the Voyagers' deputy project scientist in 2022. Before Rankin, Stone refused to advise graduate students for about 25 years. Later, Rankin became the Voyager's deputy project scientist.

The Voyager mission visited all four giant planets and is the only spacecraft that visited Uranus and Neptune. It is NASA's longest-running spacecraft mission. In 2022, Stone retired after holding the role of the Voyager project scientist for 50 years.

Simultaneously with being the Voyager's project scientist, Stone taught first-year physics at Caltech, using examples from it: "The wonderful thing about planetary fly-bys is there’s a lot of freshman physics that you can talk about: the encounters, the trajectories." but don't list these missions. Stone himself said that "[Before Voyager] My first space mission was in 1961 and I had flown instruments on missions in 1965, '67, '69, '72, and '73 – so I had lots of instruments in space, but they had all been on Earth-orbiters." and IMP-8 (1973), was involved into the cancelled ASTROMAG (1980s), the PI of SAMPEX (1992), the PI for the Advanced Composition Explorer (1997), Stone also "oversaw the redesign of the cooling system" on the Spitzer Space Telescope (2003),

In 1991, Ed Stone–a well-known, enthusiastic and respectable scientist–was made the JPL director. His directorship was during the difficult period of the 90s: with the Cold War and the Space Race between the US and the USSR finished, NASA saw dwindling budgets and introduced the so-called "faster, better, cheaper" approach, that encouraged smaller, cheaper missions built with the help of third-party contractors, efficiently "commercializing" the research lab and forcing it to work with industry. The plans were to downsize the lab and fire around 30% of JPL personnel by the end of the decade; Stone and Caltech leadership even feared that JPL could be closed.

JPL had little experience in small missions at the time: its "flagship" missions, like Voyager, Cassini, and Galileo, employed hundreds of people for decades. Cassini, for example, "directly supported maybe 500 work-years, about 10 percent of total lab staff [and] provided close to 20 percent of the lab budget".

Personal life Stone was a shy man, and worked 100-hour weeks at times. Alan C. Cummings, the Cosmic Ray Subsystem co-investigator, who worked with Stone for fifty years, described him as "very calm ... the smartest guy I ever met. He was a multiplexer supreme." Stone was profiled in 1990 for The New York Times by Michael Norman:

Stone was known as "an incredibly fast walker":

Awards and honors

In 2002, JPL established the Edward Stone Award for Outstanding Research Publication, which is awarded annually to JPL employees in both science and engineering.

In 2012, a middle school was named in Stone's honor in Burlington, his hometown.

In 2013, Stone was awarded the NASA Distinguished Public Service Medal, the highest NASA award for non-governmental employees. NASA arranged the award ceremony to be performed during The Colbert Report night show, with the award presented by Stephen Colbert dressed in a retrofuturistic spacesuit. Stone was unaware of the award when he came to the show. It was given "for a lifetime of extraordinary scientific achievement and outstanding leadership of space science missions, and for his exemplary sharing of the exciting results with the public."

In 2023, the W. M. Keck Foundation endowed the Edward C. Stone Professorship at Caltech. Christopher Martin, director of Caltech Optical Observatories, became the first Stone Professor.

In 2024, the Edward Stone Voyager Exploration Trail was unveiled at the JPL campus to commemorate Stone and his "penchant for walking". The trail starts at JPL Mall and consists of two paths, made similar to Voyager 1 and 2 trajectories. The trail features 24 memorial plaques, designed to "evoke the Golden Record" commemorating the mission's and Ed Stone's personal milestones.

Ed Stone and Voyager mission team members gave a framed copy of an iconic Voyager 1 solar system image that includes Earth as a "Pale Blue Dot" to President George H. W. Bush on June 7, 1990.

List of awards

1980 The Collier Trophy on behalf of the Voyager team 1984 Member of the National Academy of Sciences 1991 National Medal of Science 1992 COSPAR Award 1992 Magellanic Premium 1993 Member of the American Philosophical Society 1996 Space Flight Award 1999 Carl Sagan Memorial Award 2007 Philip J. Klass Award for Lifetime Achievement 2011 AIAA Goddard Astronautics Award 2013 NASA Distinguished Public Service Medal 2013 IAF World Space Award 2013 Ó Ceallaigh Medal 2014 Howard Hughes Memorial Award 2015 The Alumni Medal of the University of Chicago 2019 Shaw Prize in Astronomy 2022 Benjamin Franklin Medal

Selected publications