Edward Stone, 88, physicist who oversaw Voyager missions, is dead
Edward C. Stone, the visionary physicist who sent NASA’s Voyager spacecraft to drive rings around the outer planets of our solar system and, for the first time, go further to unravel interstellar mysteries, died Sunday at his home in Pasadena, California. He was 88.
His death was confirmed by his daughter Susan C. Stone.
Inspired by the launch of the Soviet satellite Sputnik in 1957 while he was a student, Dr. Stone twenty years later would oversee the Voyager missions for the Jet Propulsion Laboratory, which the California Institute of Technology manages for NASA.
Two spacecraft, Voyager 1 and Voyager 2, were launched separately in the summer of 1977 from Cape Canaveral, Florida. Nearly five decades later, they continue their journeys into deep space and continue to collect data.
Dr. Stone was the program’s chief project scientist for fifty years, beginning in 1972, when he was a 36-year-old physics professor at Caltech. He became the public face of the project with the double launch in 1977.
Taking advantage of the gravitational convergence of four planets, which occurs only once every 176 years, the spacecraft flew past Jupiter, Saturn, Uranus and Neptune.
The spacecraft produced the first high-resolution images of the four planets, the rings of Jupiter, Uranus and Neptune, lightning on Jupiter and lava lakes revealing active volcanoes on Jupiter’s moon Io.
“We were on a mission of discovery,” said Dr. Stone to The New York Times in 2002. “But we didn’t realize how many discoveries would happen.”
In 2012, Voyager 1 became the first human-made object to cross the heliopause boundary, where the solar wind of subatomic particles battles the force of other suns. Voyager 1 is now estimated to be 15 billion miles from Earth and traveling at 38,000 mph. according to NASAVoyager 2 crossed the boundary into interstellar space in 2018.
“The two spaceships will be Earth’s ambassadors to the stars, circling the Milky Way for billions of years,” Dr. Stone once said.
His leadership in the Voyager project earned him the National Medal of Science from President George HW Bush in 1991.
As director of the Jet Propulsion Laboratory in Pasadena from 1991 to 2001, Dr. Stone oversaw the Mars Pathfinder mission and the wheeled Sojourner rover; the Galileo spacecraft’s orbital mission to Jupiter; the launch of the Cassini spacecraft to Saturn and its rings and moons, a joint project between NASA, the European Space Agency and the Italian Space Agency; and a new class of Earth science satellites.
Dr. Stone also served as president of the California Association for Research in Astronomy from the late 1980s through the 1990s, which WM Keck Observatory in Hawaii.
In 2014, he became the founding director of the Thirty Meter Telescope International Observatory, also in Hawaii. He held that position until 2022, when he retired as Voyager’s chief scientist.
In a statement, Caltech President Thomas F. Rosenbaum called Dr. Stone “a great scientist, a formidable leader, and a gifted interpreter of discoveries.”
Edward Carroll Stone Jr. was born on January 23, 1936, in Knoxville, Iowa, southeast of Des Moines, and grew up near Burlington, on the banks of the Mississippi River. His father, Edward Sr., owned a small construction company, and his mother, Ferne Elizabeth (Baber) Stone, kept the books.
“Our father was a construction supervisor who enjoyed learning new things and explaining how they worked,” Dr. Stone wrote when he won the 2019 Shaw Prize in Astronomy for his work on the Voyager missions.
He received an Associate of Arts degree in physics from Burlington Junior College (now Southeastern Community College) and earned master’s and doctoral degrees from the University of Chicago.
Dr. Stone married Alice Trabue Wickliffe in 1962. She died in 2023. In addition to his daughter Susan, he is survived by a daughter, Janet Stone, and two grandsons.
Shortly after he began his studies, the news that the Soviets had launched a satellite turned his fascination with physics to space exploration and, in particular, to cosmic rays, the particles that come from stars and travel through the universe at warp speed.
Inspired by his doctoral supervisor John A. Simpson, Dr. Stone conducted his first experiments with cosmic rays in 1961 while working on Discover 36, a U.S. Air Force spy satellite.
He joined the faculty at Caltech in 1964. As chairman of the university’s Department of Physics, Mathematics and Astronomy, a position he held from 1983 to 1988, he helped establish the Laser Interferometer Gravitational-Wave Observatory, which later discovered ripples in space and time called gravitational waves . waves.
Norman Haynes, who served as Voyager’s overall project manager for many years, once said that Dr. Stone, through his scientific expertise and management skills, “revolutionized the world of project science.”
In 1990, Dr. Stone acknowledged the irony of his most important project: despite all its discoveries, he would not see its conclusion before he died.
“I had so much fun on Voyager,” he told The New York Times Magazine, “that I would do it again, even if I never saw the edge of the solar system.”
Dr. Stone was eventually allowed to witness the twin spacecraft’s departure from the solar system on two occasions.
“I keep wondering why there is so much public interest in space,” he said. “It’s just fundamental science, after all. The answer is that it gives us a sense of the future. If we stop discovering new things, the concept of the future will change. Space reminds us that something has yet to happen, that life will continue to evolve. It gives us direction, an arrow in time.”
