Ed Stone, the scientist who guided NASA to success Voyager Mission James Lange, who for 50 years traveled to the outer planets and led the Jet Propulsion Laboratory and landed the first rover on Mars, died Tuesday at 88.
A physicist who was involved in the early days of space exploration, Stone played a leading role in NASA’s missions to Mars, Jupiter, Saturn, Uranus and Neptune. The discoveries he made revolutionized scientists’ understanding of the solar system and fueled humanity’s ambition to explore distant worlds.
Carolyn Porco, who worked on imaging on JPL’s Voyager and Cassini missions, called Stone “a very sweet man” who was “the closest thing to perfection as a project scientist I’ve ever seen.”
“When two science teams were in conflict over a spacecraft resource and Ed had to choose between the two, the loser also walked away thinking, ‘Well, if that’s what Ed decided, it must be the right answer,'” Porco said Tuesday via email. “I feel blessed to have known Ed. And like many people today, I’m deeply saddened to learn that he’s gone.”
Stone was a 36-year-old Caltech physics professor in 1972 when he was asked to serve as chief scientist for a bold plan to send two spacecraft to explore the solar system’s four giant planets for the first time.
It was the biggest opportunity of his life, but he wasn’t sure he wanted to do it.
“I was hesitant because I was a fairly young professor at the time. I still had a lot of research to do,” he recalled 40 years later.
He accepted it anyway, and from the mission’s first encounter with Jupiter in 1979 to its final flyby of Neptune in 1989, Stone became the scientific face of the Voyager missions. He guided the science agenda and helped people understand the revolutionary images and data not only from Jupiter, Saturn, Uranus and Neptune, but also from their many fascinating moons.
Stone and his more than 200 scientific colleagues were the first to discover lightning on Jupiter and volcanism on its moon Io. They also discovered six moons around Saturn that had never been seen before and found evidence of the solar system’s largest ocean on Jupiter’s moon Europa, as well as geysers on Neptune’s moon Triton.
“It seemed like wherever we looked, we were surprised as we came across the planets and their moons,” Stone told the Los Angeles Times in 2011. “We were finding things we had never imagined, giving us a clearer understanding of Earth’s environment. I can remember every part of it even with my eyes closed.”
Voyager 1 spacecraft becomes The first man-made object to reach interstellar space in 2012, and Voyager 2 did the same thing In 2018.
Stone, pictured with a model of the Voyager spacecraft, said the discovery of volcanoes on Io was a highlight of the mission.
(NASA)
Sending twin probes continues Weekly Communication From interstellar space to Earth. Stone retired On the 50th anniversary of the mission in 2022.
“A part of Ed lives on in the two Voyager spacecraft. His dedication and skilled leadership are reflected in the Voyager missions,” said Linda Spilker, who joined the mission in 1977 and replaced him as project scientist.
The Voyager mission was Stone’s greatest accomplishment, but not his only one.
He was the principal investigator for nine NASA missions and co-investigator for five others, including several satellites designed to study cosmic rays, the solar wind, and the Earth’s magnetic field.
He became the director Jet Propulsion Laboratory at La Cañada Flintridge in 1991, a position he held for a decade.
This was an era of cost-cutting at NASA, but Stone still managed to launch Galileo’s five-year mission to Jupiter send more Cassini spacecraft to Saturn. He was also the head of the agency when Mars Pathfinder delivers Sojourner rover This was the first time humans sent a robot to the surface of another planet.
During his tenure at JPL, Stone continued to work and teach at Caltech, even teaching physics to new students during Voyager’s long journeys between the planets.
He also served as chairman of the board of the California Association for Astronomy Research, which is responsible for the construction and operation of the Astronomy Research Center. W.M. Keck Observatory And it has two 10-meter telescopes on Mauna Kea in Hawaii.
Edward Carroll Stone Jr. was born Jan. 23, 1936, in Iowa and grew up in Burlington, where his father ran a small construction business and his mother did the company’s bookkeeping.
The eldest of two brothers, Stone was fascinated by science from a young age. Under his father’s supervision, he learned to disassemble and reassemble all kinds of technology, from radios to cars.
“I’ve always been interested in knowing why something is this way and not that way,” says Stone told an interviewer in 2018. “I wanted to understand, measure, and observe.”
After studying physics at Burlington Junior College, he earned master’s and doctorate degrees from the University of Chicago. Shortly after he began his graduate studies, news arrived in 1957 that the former Soviet Union had launched Sputnik, the world’s first artificial satellite.
“Just like that, because of the Cold War and our need to cope with Sputnik, a whole new field opened up,” he said.
Stone invented an instrument for measuring the intensity of solar energy particles It traveled into space above the atmosphere aboard an Air Force satellite in 1961. Unfortunately, the spacecraft’s transmitter was not working, so only a very limited amount of data was transmitted back to Earth. However, it was still enough to indicate that the intensity of the particles was lower than expected.
Despite the transmitter glitch, Stone said the project was exciting. “We were taking the first steps into a completely new field of research and exploration,” he said. “We were just at the beginning.”
He joined the faculty of Caltech in 1964 and conducted more space experiments, this time for NASA.
Stone’s area of special interest was Cosmic Rays – High-speed atomic nuclei that may arise from explosive events on the Sun or from violent events outside the Solar System.
One of his cosmic-ray experiments was included in the 11 major Voyager experiments.
Ed Stone made the discovery in 2011, about a year before Voyager 1 entered interstellar space.
(Al Seib/Los Angeles Times)
Colleagues praised Stone for his leadership of the Voyager science team.
“He was a great hero, a giant among men,” Porco said, adding that Stone was known for treating everyone — from top scientists to graduate students — with respect.
Voyager Team Scientists Thomas Donahue Put it this way: “Over the years, Ed Stone has proven remarkably adept at keeping a number of veterans on track.”
Stone was elected to the National Academy of Sciences in 1984 and was awarded the National Medal of Science by President George H. W. Bush in 1991 for his leadership of the Voyager missions. Shaw Prize in Astronomy 2019An honor that comes with a $1.2 million prize. In 2012 his hometown of Burlington, Iowa named their new city after him middle School After that.
“It’s truly an honor because it comes from the community where my exploration journey began,” Stone told A local newspaper.
Decades after Voyager’s launch, he was asked to choose his favorite moment from the mission. He chose the discovery of volcanoes. Jupiter’s moon Io,
“It was really quite surprising to find a moon with 100 times more volcanic activity than the entire Earth,” he said. “And that’s exactly what Voyager was going to do for the rest of its journey into the outer solar system.
“Over and over again we find that nature is far more inventive than our models,” he said.
His wife, Alice, whom he met on a blind date at the University of Chicago and married in 1962, dead The couple is survived by two daughters, Susan and Janet Stone, and two grandchildren.
