JPL Chief Leaves Legacy of Far-Flung Space Exploration
They are arranged on Ed Stone’s office shelf in the order they appear in the vast emptiness of space: thick books about Jupiter, Saturn, Uranus and Neptune, some of the solar system’s most distant planets.
They are lonely worlds, places that would have remained almost complete mysteries, were it not for the pioneering teams of explorers headed by Stone--first as leader of the historic Voyager missions and then, for the last decade, as head of NASA’s Jet Propulsion Laboratory in Pasadena.
At 65, the traditional retirement age for JPL chiefs, Stone is preparing to leave the agency and return to a relatively quiet life as a Caltech physicist.
He will leave behind the storms of controversy that followed the losses of two costly Mars spacecraft in 1999, a nonstop battle to conduct difficult space missions under tight cost constraints and a legacy in space exploration that few can surpass.
In a career divided, not by decades but by planets, Stone made his first mark with the Voyager missions of the 1970s and ‘80s. In what became known as a grand tour of the planets, the spacecraft took a slingshot course past massive Jupiter, Saturn and its 1,000 ringlets, Uranus and even frigid blue Neptune, 2,800 million miles from the sun.
Along the way, Voyager found many things that are still being studied: rings around Jupiter and numerous volcanoes and hints of frozen oceans on its distant moons, Europa and Ganymede. Far from finding cold, dead planets, Voyager found heat and atmospheres and strange weather--even on faraway Neptune.
“What we know of the outer planets is a direct result of Ed Stone’s contribution,” said Tom Young, the former director of NASA’s Goddard Space Flight Center and former president of aerospace giant Martin Marietta. “He was one of two or three people that made Voyager tick.”
The path to the stars was not an obvious one.
The son of a garage-door manufacturer in small-town southeastern Iowa, Stone was 21 when the Soviets ushered in the Space Age with the basketball-sized satellite Sputnik I. His interest in space and physics was encouraged first by a high school physics teacher, Wilfred White, and then by his graduate school advisor at the University of Chicago, John Simpson, who was among the first scientists to launch experiments into outer space.
“I could not have planned, even if I had thought of it, a career like I have today,” Stone said during an interview in his office overlooking the expansive campus of JPL, the NASA center responsible for unmanned planetary exploration. “I was just there at the right time.”
Stone is best known to the public for his appearances on the evening news during the Voyager days. But it was not planets that first caught the quietly studious Stone’s attention: It was the wrenching violence of cosmic rays--particles from exploding stars that rip through space at nearly the speed of light.
Physicists know Stone best for his work at Caltech’s Space Radiation Laboratory, where he found ways to capture and measure the content of cosmic rays and to study the particles hurled outward by the sun during its furious solar storms. That research has earned him a spot in the National Academy of Sciences.
With Richard Mewaldt of Caltech and others, Stone is running a series of high-energy physics experiments. Even as he headed JPL, he has found time to be the principal investigator for a satellite called ACE that hovers between Earth and the sun, capturing particles that stream past with an efficiency that makes other scientists gape.
“It’s what I call the Ed Stone touch. You don’t just take what’s there, you take it to the level where other people will eat their hearts out,” said Tom Tombrello, a physicist who holds another of Stone’s former jobs: head of the division of physics, mathematics and astronomy at Caltech.
Stone is also a rare bird: a scientist who can manage. He is legendary for his deft political touch in keeping Voyager’s 11 scientific teams from each other’s throats.
“He was much more skilled at getting his team of prima donnas to work together than I was with mine, and I’m a pretty good politician myself,” said Thomas M. Donahue, a professor emeritus of planetary science at the University of Michigan who ran the Pioneer mission to Venus in 1978 and headed the sometimes delicate negotiations of the National Academy of Science’s Space Science Board.
“He was Solomon-like,” said Ellis D. Miner, a JPL veteran who became assistant project scientist for much of the Voyager mission. Often there was no arguing with Stone because he had researched the issue under discussion so thoroughly. He knew as much as the experts.
“He had a wonderful facility for finding the solution that seemed the most cool and logical,” Donahue said.
A Cool and Logical Approach
Cool and logical are the two words that seem to describe Stone best. Whether it’s good news like stunning geology from the close-up view of a new moon, or bad news, like a broken antenna arm, Stone weathers it the same way: coolly and logically. “I’ve never seen him lose control,” said Miner, who has worked closely with Stone for 23 years.
For someone so accomplished, Stone is surprisingly low-key. He dresses in muted colors, usually gray. He does not raise his voice. In a group, he is usually not the one talking. He is the one listening. Self-effacing to a fault, he attributes much of his success to the talented people who work with him and for him.
The admiration is mutual: People usually too busy to speak with reporters call back immediately when the topic is Ed Stone. Secretaries rush to praise him as “thoughtful,” “wonderful,” “the kindest man.”
His passion, when it is exhibited, is exhibited quietly.
There was the time in 1977, when Stone’s team showed that a heavy ion accelerator at Berkeley could measure particles no one had tracked before. He was so excited, he took a dozen Polaroids of the data on the screen--and handed them out as if they were pictures of a newborn, recalled his co-experimenter and former graduate student, Mewaldt.
Science appears to be Stone’s only passion, and it is all-consuming. He has no time for hobbies. “I don’t think he goes out fishing or anything,” Mewaldt said.
Because Stone’s JPL job takes nearly all his weekday time, nights and weekends are spent in his Caltech lab, just a few doors down from the house he shares with his wife, Alice. At Caltech, he pores over data from his little ACE satellite, hoping to determine what actually makes up the sun. Since 1988, he has also led the board that operates the world’s largest telescope, Mauna Kea’s Keck Observatory in Hawaii.
Late nights are no problem for Stone: He has more energy than scientists half his age, reports David Baltimore, the president of Caltech, who has seen Stone weather a red-eye flight to Washington and stand through daylong meetings without complaint. Stone does everything fast: walk, talk, drive. He is a difficult man to outpace.
Before taking the JPL job, Stone, who was a Caltech vice president, had more time for the little things. He was photographed in People magazine in 1980, for instance, changing his own oil.
He no longer has time for that, but he did make each of his two daughters learn how to take apart and rebuild a car before letting them get their drivers’ licenses.
The source of all this energy issuing from the rail-thin Stone remains one of the man’s greatest mysteries. As does his ability to get so much done. “Perhaps,” said Tombrello, “he’s not quite human.”
Added Mewaldt: “He doesn’t waste time thinking about things that aren’t important.”
Stone is also extremely organized. His notebooks--one neatly inscribed book for each mission--are the stuff of legend among his colleagues. They contain every thought, every question, every important idea that passed through his head during a project.
“A little piece of scientific history, I guess,” said Stone, surprised to hear of the fame his notebooks have inspired.
Slew of Challenges Along the Path
Despite his stellar record, he has encountered a slew of difficulties. “Voyager had hundreds of major problems,” Miner recalled.
But Stone faced the biggest challenge of his career in 1999, when NASA lost $360 million in Mars probes--an orbiter and a lander--because of simple errors. This was not an engineering problem, a stuck antenna or a balky receiver that could be cleverly fixed. These were losses--hard on NASA, hard on JPL and hard on Stone.
“When it works well, it looks so much easier than it really is,” Stone said of space exploration. “When it doesn’t work, you realize how many thousands of individual decisions have to be made, and can go wrong.”
Although much of the blame went to NASA chief Dan Goldin, who was accused of trying to do too much too cheaply in the space program without sufficient personnel and oversight, Stone’s management of JPL took its knocks as well. One follow-up investigation was headed by Tom Young, who was in the difficult position of having to write a critical report about a close colleague and friend.
“Things were not done as well as they should have been done. But my personal belief is that JPL has taken corrective action,” Young said. “Through the whole affair, I must tell you, my respect and admiration for Ed Stone has never wavered.”
Stone began in a space program that found it difficult to even reach the planets and at first sent back data in sluggish streams of 8.3 bits per second. Today’s missions beam images back almost instantly to a wide Internet audience.
Stone is staying on until his successor is chosen, perhaps in the spring. That person will advance into new eras of exploration: first, bringing samples from Mars and elsewhere back to Earth for study and one day sending humans to colonize other planets.
But he will take with him control of the Voyager crafts, which are still hurtling toward the edge of the solar system.
With luck, the most distant of the twins, Voyager I, will soon hit a giant shock wave far past Pluto, where the million-mile-an-hour solar wind slows abruptly and starts flowing back toward the sun.
Although they are long past their original four-year life spans, the two spacecraft have enough energy to keep traveling until 2020. The battered Voyager I may even make it to the heliopause--the distant reaches where the sun’s influence ends--in time for Stone and his colleagues to study it.
“Voyager passed Neptune in 1989,” said Stone, “but its journey is not over yet.”
Neither, it’s clear, is Ed Stone’s.
