Edward Stone, 88, the physicist who oversaw the Voyager missions, has died

Edward C. Stone, the visionary physicist who sent NASA’s Voyager spacecraft to loop around the outer planets of our solar system and, for the first time, venture farther to uncover interstellar secrets, died Sunday at his home in Pasadena, California. 88.

His daughter, Susan C. Stone, confirmed his death.

Inspired by the launch of the Soviet satellite Sputnik in 1957, when he was an undergraduate, Dr. Stone went on to supervise Voyager missions 20 years later for the Jet Propulsion Laboratory, which the California Institute of Technology runs for NASA.

They were twin spacecraft, Voyager 1 and Voyager 2 Launched separately In the summer of 1977 from Cape Canaveral, Florida. Nearly five decades later, they are still continuing their journeys into deep space and still collecting data.

Dr. Stone was the program’s chief project scientist for 50 years, starting in 1972, when he was a 36-year-old professor of physics 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 that 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 that revealed active volcanoes on Jupiter’s moon Io.

“We were on a mission of discovery,” Dr. Stone told the New York Times in 2002. But we did not estimate the extent of discoveries that would be there.”

In 2012, Voyager 1 became the first man-made object to cross the heliosphere boundary, where the powerful solar wind of subatomic particles succumbs to the force of other suns. Today, Voyager 1 is estimated to be 15 billion miles from Earth and traveling at 38,000 miles per hour. According to NASA. Voyager 2 crossed the border into interstellar space in 2018.

“The two spacecraft will be Earth’s ambassadors to the stars, orbiting the Milky Way for billions of years,” Dr. Stone once said.

His leadership of the Voyager Project earned him the National Medal of Science in 1991 from President George H.W.

As director of the Jet Propulsion Laboratory in Pasadena from 1991 to 2001, Dr. Stone oversaw the Mars Pathfinder mission and its wheeled Sojourner rover; Orbital mission of the Galileo space probe to Jupiter; release Cassini Spacecraft to Saturn, its rings and moons, a joint project involving NASA, the European Space Agency and the Italian Space Agency; And a new class of Earth science satellites.

From the late 1980s through the 1990s, Dr. Stone also served as president of the California Society for Astronomical Research, which built and operated the probe. W.M. Keck Observatory In Hawaii.

In 2014, he became founding executive director of the International Thirty Meter Telescope Observatory, also in Hawaii. He held this position until 2022, when he retired as Voyager’s chief scientist.

In a statement, Thomas Rosenbaum, president of the California Institute of Technology, called Dr. Stone “a great scientist, a tremendous 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, Fern Elizabeth (Baber) Stone, kept the company’s books.

“Our father was a construction supervisor and enjoyed learning new things and explaining how they worked,” Dr. Stone wrote when he received the 2019 Shaw Prize in Astronomy for his work on the Voyager missions.

He earned an Associate of Arts degree in physics from Burlington Junior College (now Southeastern Community College) and his master’s and doctoral degrees from the University of Chicago.

Dr. Stone married Alice Trabo Wycliffe in 1962. She died in 2023. In addition to his daughter, Susan, he leaves behind another daughter, Janet Stone. and two grandchildren.

Shortly after he began graduate studies, news came that the Soviets had launched a satellite, focusing his fascination with physics on space exploration and, in particular, cosmic rays, particles that come from stars and travel through the universe at tremendous speed.

Inspired by his doctoral advisor, John A. Simpson, Dr. Stone conducted his first cosmic ray experiments in 1961 while working on Discover 36, an Air Force spy satellite.

He joined the faculty at Caltech in 1964. As head of the university’s Department of Physics, Mathematics, and Astronomy, a role 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.

Dr. Stone, with his scientific expertise and management skill, “revolutionized the world of enterprise science,” said Norman Haynes, who for years was general manager of the Voyager project.

In 1990, Dr. Stone acknowledged the irony of his signature project, which was that even with all his discoveries, it would not see its end before his death.

“I enjoyed Voyager so much that even if I never saw the edge of the solar system, I would do it again,” he told New York Times Magazine.

Dr. Stone was eventually able to watch the twin spacecraft leave the solar system twice.

“I keep asking myself why there is so much public interest in space,” he said. “It is, in the end, just basic science in the end. The answer is that it provides us with a sense of the future. When we stop discovering new things, the concept of the future will change. Space reminds us that something needs to be done, and that life will continue to evolve. It gives us direction, An arrow at the right time.