Humanity has lost an interstellar pioneer.
Ed Stone, who served as project scientist for NASA’s groundbreaking Voyager mission from 1972 to 2022, died on Sunday (June 9) at the age of 88.
“Ed Stone was a pioneer who dared mighty things in space. He was a dear friend to all who knew him and a valued mentor to me personally,” said Nicola Fox, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. in NASA’s obituary for Stone, which the agency released Tuesday (June 11).
“Ed took humanity on a planetary journey through our solar system and beyond, sending NASA where no spacecraft had gone before,” added Fox. “His legacy left a huge and profound impact on NASA, the science community and the world. My condolences to his family and all who loved him. Thank you, Ed, for everything.”
Related: Interstellar Journey: Q&A with Voyager Project Scientist Ed Stone
Voyager launched two probes in 1977 on a “grand tour” of the solar system’s giant planets. Both probes made many discoveries in our cosmic backyard—finding intense volcanism on Jupiter’s moon Io and the 10 new moons of Uranus, for example—and then continued to fly, into exciting and unexplored realms.
In 2012, Voyager 1 broke free from the heliosphere, the vast bubble of charged particles and magnetic fields that the Sun blows around itself, becoming the first man-made object ever to reach interstellar space. Voyager 2, which took a different path and moves slightly slower than its partner, followed in late 2018.
Both Voyagers remain operational today, studying the exotic environment between our star and another. Voyager 1 is currently more than 15 billion miles (24 billion kilometers) from home, and its twin is about 13 billion miles (21 billion km) in the void. This is about 162 and 136 Earth-Sun distances (or astronomical units).
“It has been an honor and a pleasure to serve as Voyager project scientist for 50 years,” Stone said in a NASA statement in October 2022 announcing his retirement from the role.
“The spacecraft succeeded beyond expectations and I appreciated the opportunity to work on this mission with so many talented and dedicated people,” he added. “It’s been a remarkable journey, and I’m grateful to everyone around the world who watched Voyager and joined us on this adventure.”
Related: Voyager: 15 incredible pictures of our solar system (gallery)
Stone was born on January 23, 1936 in Knoxville, Iowa, according to a NASA obituary. His father was a construction supervisor who enjoyed showing his son how to take things apart and put them back together – and young Ed was a keen student.
“I’ve always been interested in why something is the way it is and not the other way,” Stone said in a 2018 interview, according to a NASA obituary. “I wanted to understand and measure and observe.
He studied physics in junior college, then went to the University of Chicago for graduate school, where he helped build scientific instruments for spacecraft—still a very young field at this stage.
“The first he proposed was aboard Discoverer 36, the since-declassified spy satellite that launched in 1961 and took pictures of Earth from space as part of the Corona program,” NASA wrote in an obituary. “Stone’s instrument, which measured energetic particles from the Sun, helped scientists understand why solar radiation fogs the film and ultimately improved their understanding of the Van Allen Belts, energetic particles trapped in Earth’s magnetic field.”
Stone became a postdoctoral fellow at the California Institute of Technology (Caltech) in 1964 and soon began working on NASA missions. Over the years, he served as principal investigator or science instrument leader on nine different agency missions and co-investigator on five others, according to the agency.
Stone also served as director of the Jet Propulsion Laboratory (JPL) in Southern California—the agency’s lead center for robotic planetary exploration—from 1991 to 2001. That stretch saw several major milestones, including the landing of NASA’s first-ever Mars rover, Sojourner. , in 1996 with the Pathfinder mission and the launch of the Cassini-Huygens mission to Saturn (a joint effort with the European Space Agency) in 1997.
“Ed will be remembered as an energetic leader and scientist who expanded our knowledge of the universe—from the Sun to the planets to distant stars—and fueled our collective imagination about the mysteries and wonders of deep space,” said JPL Director Laurie Leshin, who is also vice president Caltech, NASA said in its obituary.
“Ed’s discoveries have fueled the exploration of previously unseen corners of our solar system and will inspire future generations to reach new frontiers,” added Leshin. “He will be greatly missed and always remembered by the NASA, JPL and Caltech communities and beyond.”
Stone’s colleagues have repeatedly noted his dedication to science education and communication, his genuine desire to help inform the world about scientific results in a way that is both accurate and engaging.
I can attest to this commitment as I have witnessed it firsthand on numerous occasions. Although very busy, Stone was open and available to the media; he took our phone calls and stayed after press conferences to answer more and more of our questions.
And in all these interactions he was unfailingly kind, polite and patient. I didn’t know Ed Stone well, but I could tell he was a good man. And I, like countless others, will miss him.