How Legendary Physicist Richard Feynman Helped Crack the Case on the Challenger Disaster
Kevin Cook on the Warnings NASA Ignored, With Tragic Results
Richard Feynman’s phone rang. The caller was William Graham, a former student of his at Caltech, now acting director of NASA. Feynman didn’t remember Graham and didn’t like the sound of what he was calling to offer: a seat on the Presidential Commission on the Space Shuttle Challenger Accident. Feynman said, “You’re ruining my life!”
At 67, the Nobel Prize-winning physicist was perhaps the most famous scientist in the world. During World War II, he had worked on the Manhattan Project that built the atom bomb. During the late 1940s and early 1950s, he helped crack the sub- atomic code of quantum electrodynamics, inventing “Feynman diagrams” to show how light and matter interact. By the winter of 1985–86, Caltech’s longhaired graying eminence was happy and comfortable in Pasadena, though he was still fighting a rare cancer that had almost killed him eight years before, when surgeons removed a tumor larger than a grapefruit from his stomach. Feynman never saw any point in wondering if his work on the A-bomb had caused his cancer. His theoretical work suggested that time’s forward motion may be little more than an illusion, a shortcut humans use to negotiate one of the universe’s four dimensions, but in human affairs he never looked back.
After Graham’s call he asked his wife, Gweneth, “How am I gonna get out of this?”
She urged him to join the commission. “If you don’t, there will be 12 people all going around from place to place.” If he joined, there would be 11 people following an itinerary like normal bureaucrats “while the 12th one runs around all over the place, checking all kinds of unusual things. There isn’t anyone who can do that like you can.”
As Feynman recalled, “Being very immodest, I believed her.” He went to Washington, where Graham introduced him to Neil Armstrong—“the moon man,” Feynman called him—and “the big cheeses of NASA.” He met legendary test pilot Chuck Yeager, who was as uneasy in the halls of government as he was. “I had to think about whether or not to participate,” Yeager admitted later. “I knew that NASA was screwing up.” Feynman met their fellow commissioners: astronaut Sally Ride; diplomat David Acheson, the son of former secretary of state Dean Acheson; scientists Arthur Walker and Albert Wheelon; air force officials Eugene Covert, Alton Keel, and Donald Kutyna; Aviation Week editor Robert Hotz; and chairman William Rogers, who opened the hearings of what the media dubbed the Rogers Commission on February 6, 1986, nine days after the accident and more than a month before the crew cabin was found. Rogers, 72, was a patrician New Yorker in a charcoal suit and a red-white-and-blue-striped tie. He had a high forehead and a level gaze that gave nothing away. Rogers also had a mandate from President Reagan.
“Whatever you do,” Reagan had told him, “don’t embarrass NASA.”
The chairman had no plan to do so. “We are not going to conduct this investigation in a manner which would be unfairly critical of NASA,” he announced at the commission’s first session, “because we think—I certainly think—NASA has done an excellent job, and I think the American people do.”“Whatever you do,” Reagan had told him, “don’t embarrass NASA.”
The first witness to appear before the commission was Graham, the agency’s acting director. He raised his right hand and swore to tell the truth. A lean 48-year-old with wire-rim glasses and a wispy brown mustache, Graham had been a nuclear-weapons specialist at the Rand Corporation before joining NASA. He began by addressing the commissioners. “NASA welcomes your role in reviewing and considering the facts and circumstances surrounding the accident of the space shuttle Challenger,” he said. “You can be certain that NASA will provide you with its complete and total cooperation.” That would turn out to be false.
Rogers and several other commissioners had no knowledge of aerospace matters, so a parade of agency officials followed Graham, describing how the shuttle worked. That left the scientists on the panel sitting through explanations of physics and engineering littered with what Feynman called “the crazy acronyms that NASA uses,” from SRB and ET to LOX (liquid oxygen), HPFTP (high-pressure fuel turbo pump), and HPOTP (high-pressure oxygen turbo pump). Feynman complained to his wife about “how inefficient a public inquiry is: most of the time, other people are asking questions you already know the answer to.” Inefficiencies drove him to distraction. “Although it looked like we were doing something every day in Washington, we were, in reality, sitting around doing nothing most of the time.”
Feynman spent his free hours chatting with physicists at NASA headquarters on E Street, a short walk from his Washington hotel. When Rogers heard about that, the chairman issued an order barring the gadfly Nobelist from the building. Too late—Feynman had already learned what he needed to know.
He discovered that some of the agency’s managers had been “fooling themselves.” Asked to estimate the risk of a catastrophic accident that would destroy a space shuttle and its crew, they put the odds at 1 in 100,000. As Feynman wrote in his memoir “What Do You Care What Other People Think?”, that number meant that they “could launch a shuttle each day for 300 years expecting to lose only one.” Engineers put the risk closer to 1 in 200, leading him to wonder, “What is the cause of management’s fantastic faith in the machinery?” He was willing to bet it had to do with a logical fallacy: “NASA had developed a peculiar kind of attitude: if one of the seals leaks a little and the flight is successful, the problem isn’t so serious. Try playing Russian roulette that way: you pull the trigger and the gun doesn’t go off, so it must be safe to pull the trigger again.”
He asked seemingly simple questions: What were the boosters’ O-rings made of? Did NASA have a quality-control department? Did someone have final say on whether to launch or not to launch, or was responsibility diffused to the point that nobody could be blamed for anything in particular? But when he pressed commission witnesses for details, the chairman cut him off. One afternoon, “Mr. Rogers brought the meeting to a close while I was in midstream! He repeated his worry that we’ll never really figure out what happened to the shuttle.”
The commission’s work gained urgency on Sunday, February 9, when the New York Times reported that NASA had been warned about problems with the O-rings—not only recently but for years. Later that day, NASA chief Graham treated Feynman to a movie at the Smithsonian’s National Air and Space Museum. They attended a VIP showing of The Dream Is Alive, an IMAX film on the shuttle program. Featuring footage saved from the 1984 mission when Resnik’s hair got caught in the camera, the movie “was so dramatic that I almost began to cry,” Feynman remembered. As for Challenger, “I could see that the accident was a terrible blow. To think that so many people were working so hard to make it go—and then it busts—made me even more determined to help straighten out the problems of the shuttle as quickly as possible, to get all those people back on track.” With the shuttle program on hold pending the findings of the Rogers Commission, thousands of NASA employees were eager to get back to work. “After seeing this movie,” he wrote, “I was very changed, from my semi-anti-NASA attitude to a very strong pro-NASA attitude.”
After the film he got another surprise phone call. Air force general Kutyna, another commission member who had become a friend, invited Feynman to his house for dinner that evening.
The general had an agenda. Earlier in the week, their fellow commissioner Sally Ride had slipped Kutyna a sheet of paper: a NASA document the agency was keeping from the press, the public, and the presidential commission. It held two columns of numbers, one showing the air temperature at previous shuttle launches, the other showing the resilience of rocket boosters’ O-rings at various temperatures. The correlation was clear: the boosters’ rubber O-rings didn’t work as well at low temperatures. Ride, a NASA employee, was risking her job by leaking an internal document to Kutyna. He recognized its importance but couldn’t reveal that it came from an astronaut. So he asked Feynman over for dinner.The commission’s work gained urgency when the Times reported that NASA had been warned about problems with the O-rings.
After a pleasant meal the general gave the scientist a tour of his garage, which was littered with tools and auto parts. Kutyna, a car buff, had been working under the hood of a sporty Opel GT. Feynman saw the carburetor laid out on a workbench. There are several accounts of their conversation that night; in all of them, Kutyna says something like, “Professor, the rings in the engine leak when it’s cold outside. Do you think cold weather might affect O-rings?”
Feynman recalled it as a head-slapping moment. “Oh!” he said. “It makes them stiff. Yes, of course!”
The next morning—Monday, February 10—the two of them stopped by Graham’s office at NASA headquarters. According to Feynman, they “asked if he had any information on the effects of temperature on the O-rings.” Graham said no, but promised “he would get it to us as soon as possible.”
That day’s hearing was closed to the press. Rogers opened by denouncing the press for revealing that NASA had ignored warnings about the O-rings. “I think it goes without saying that the article in the New York Times and other articles have created an unpleasant, unfortunate situation,” the chairman said, adding, “There is no point in dwelling on the past.” Still Rogers couldn’t avoid addressing the thrust of the Times story: that every launch dating back to the shuttle program’s first year had been an accident waiting to happen. With the press barred from that day’s closed session, he invited NASA and Morton Thiokol officials to explain why.
Lawrence Mulloy, director of the agency’s rocket-booster program, swore that each step of the countdown to Challenger’s launch followed established procedures. Mulloy, a 25-year veteran of the space program, reported to Lucas—the Huntsville czar who would not take “not ready” for an answer. When Ride pressed him, asking Mulloy if he or the executives and engineers who worked for him had any concerns about the boosters’ O-rings, he said, “I don’t recall any.”
Allan McDonald, director of the rocket-booster program at Morton Thiokol, raised his hand. In the chain of command that ran from NASA’s top administrators through second-level chiefs like Lucas and third-tier executives like Mulloy, McDonald was at the level just below Mulloy. Now, he stood up. “Mister Chairman,” McDonald said, “we recommended not to launch.”
That got everyone’s attention. As Feynman recalled, “Mr. Rogers decided that we should look carefully into Mr. McDonald’s story, and get more details before we made it public. But to keep the public informed, we would have an open meeting the following day, Tuesday.”
On Tuesday, Feynman woke early and hailed a cab to drive him around until he spotted a hardware store. It wasn’t open yet. The Nobel Prize–winner waited in the cold “in my suit coat and tie, a costume I had assumed since I came to Washington, in order to move among the natives without being too conspicuous.” When the shop opened he bought a clamp and a pair of pliers.
During Tuesday’s televised hearing, Feynman pressed Mulloy about the O-rings. “If this material weren’t resilient for, say, a second or two, would that be enough to be a very dangerous situation?” he asked.
“Yes, sir,” Mulloy admitted.
While the hearing continued, Feynman commandeered a scale model of the space shuttle that had been passed around the room. He used his hardware-store pliers to pull a rubber strand of O-ring off the model. Then, reasoning that the temperature of the ice water that waiters and waitresses delivered to the commissioners was close to 32 degrees—a close match for the air temperature when Challenger launched—he dunked the chunk of rubber into his ice water. He was about to speak up when Kutyna, sitting beside him, said, “Not now.” The cameras were still on Mulloy, who was droning on about the agency’s preflight preparations.
Moments later, Rogers called for a recess. During the break the chairman, standing beside Neil Armstrong at a urinal in the men’s room, was overheard saying, “Feynman is becoming a real pain in the ass.”
When they resumed, Rogers clicked a red button on his microphone. Now he was live on national TV. “Dr. Feynman has one or two comments he would like to make,” Rogers said.
Sally Ride smiled.
Feynman pressed the red button on his mic. “This is a comment for Mr. Mulloy,” he said. He held up a chunk of O-ring for the TV cameras, explaining, “I took this stuff that I got out of your seal, and I put it in ice water. And I discovered that when you put some pressure on it for awhile and then undo it, it doesn’t stretch back. It stays the same dimension. In other words, there is no resilience in this particular material when it is at a temperature of 32 degrees. I believe that has some significance for our problem.”
Rogers broke in. “That is a matter we will consider in the session we will hold on the weather,” he said, “and I think it is an important point, which I’m sure Mr. Mulloy acknowledges.” But there was no denying the impact Feynman’s demonstration had on the proceedings. His waving a chunk of chilled rubber for the cameras would be played and replayed all over the world. As Feynman’s friend and fellow physicist Freeman Dyson put it, “The public saw with their own eyes how science is done, how a great scientist thinks with his hands, how nature gives a clear answer when a scientist asks her a clear question.”
During three months of hearings that spring, Feynman continued his detective work between visits to a Washington hospital for cancer treatments. “I am determined to do the job of finding out what happened—let the chips fall!” he wrote to his wife. He expected the agency would try to overwhelm him “with data and details . . . so they have time to soften up dangerous witnesses, etc. But it won’t work because (1) I do technical information exchange and understanding much faster than they imagine, and (2) I already smell certain rats that I will not forget, because I just love the smell of rats, for it is the spoor of exciting adventure.”
Excerpted from The Burning Blue: The Untold Story of Christa McAuliffe and NASA’s Challenger Disaster by Kevin Cook. Published by Henry Holt and Company. Copyright © 2021 by Kevin Cook. All rights reserved.