On Sept. 30, the MIT community came together to celebrate the career of Institute Professor Emerita Sheila Widnall, who recently retired after spending 64 years at MIT. The virtual event featured remarks from MIT leaders, current and former secretaries of the U.S. Air Force, and Widnall’s faculty colleagues from the Department of Aeronautics and Astronautics (AeroAstro), who spoke of her impact at MIT and beyond.
MIT was not only a springboard for a hungry young tinkerer who became a remarkable engineer and a visionary leader, both at MIT and on the national stage. Widnall would also become one of the curious few who make MIT their intellectual home for their full adult lives. Her work in fluid dynamics would have major implications in aviation and space flight. She would become the first woman to lead a branch of the U.S. military when she was secretary of the Air Force in the 1990s. And her leadership in supporting women in the STEM fields, both at MIT and internationally, would blaze trails for six decades.
The call to adventure
It was a small chunk of uranium, a gift from an uncle who worked for a mining company that first brought Widnall face to face with her future.
It may seem like an odd choice of present for teenager, but in the 1950s when Widnall was in high school in Tacoma, Washington, America was hot for uranium. Hollywood produced two uranium-themed movies: “Uranium Boom” and “Dig That Uranium.” The Atomic Energy Commission was paying between $3,000 and $7,000 a ton for the stuff — half the cost of a new home.
To Widnall, however, the rock had a more practical purpose. An 11th grader at Aquinas Academy, a Catholic girls’ school, she had a science project due: “I used it, along with models of atoms, to explain radioactive decay,” she told a reporter in 2009.
Her project on the degradation of uranium won first prize at the Tacoma Science Fair, and from there it was on to a national competition. She traveled with her science teacher on a two-day, 2,000-mile train trip to Ohio, where Widnall’s life was about to change forever.
Her project impressed a Tacoma civil engineer, Arthur Anderson SM ’35, SCD ’38. As a businessman he’d developed pre-stressed concrete, which could be used to create curved beams, the kind you see in monorails like the ones at Walt Disney World. Anderson thought Widnall had a future in science and told her she should apply to his alma mater, MIT.
“Where’s that?” she asked.
Soon enough, Widnall would discover how the Institute launched the intellectually curious, helping them explore the boundary where the known meets the unknown.
From Tacoma to Cambridge
Widnall attributes the fearlessness with which she faced a career in engineering to her parents, Rolland and Genevieve Evans. At a time when women were only a third of the U.S. labor force, Widnall was unique among her friends in having a mother with a full-time job. Genevieve Evans was a probation officer whose cases sometimes required her to reach back to her earlier professional experience as a social worker. “She worked with families, kids who were accused of violent crimes,” Widnall says with pride. “It was a big deal.”
Her father, Rolland Evans, was an insurance salesman. Later in his life, he went back to school to obtain a master’s degree and teach college-level business. He also taught his daughter self-reliance. “We worked together on various projects, building things. He fixed things and I’d tag along and he’d show me how. I was 20 years old before I realized you could hire people to do work on your house,” Widnall says.
After being accepted to MIT, Widnall arrived on campus in the fall of 1956. Of 6,000 students at that time, just 2 percent were female, including 23 first-years. The women felt isolated, Widnall remembers, forced to live in a rowhouse a mile off campus. While she personally experienced few instances of outright sexism, one episode stood out: “When I came to MIT and was introduced to my freshman advisor, he said “Why are you here?’, Which I took as an insult. I thought, ‘This guy is a jerk.’ But every other advisor was supportive.”
One of these, math professor George Thomas, author of the famous textbook, “Thomas’ Calculus,” brought cookies to sustain her during a test. Another, Holt Ashley, an aeronautical engineering professor known for his patience and humor, first suggested to Widnall that she pursue an advanced degree — and she readily agreed.
By then, Widnall already knew what she would study. “I love airplanes. There was never an issue about what I was going to choose,” she says. Much later in her career, she would read reports suggesting many women entering science and engineering chose fields where they believe they can make the biggest contribution. By her example, it was true. Less than a decade into her career she’d already conducted research that had an impact in aeronautics, one that every air traveler ought to appreciate.
After obtaining her PhD in 1964, Widnall was hired as the first female faculty member in the MIT School of Engineering, where she established her research program with a focus on fluid dynamics. Eventually, she published research that analyzed vortices trailing from the wing tips of aircraft. This work was used to gauge the hazards of wake turbulence. It was no small matter, as some of the largest commercial aircraft were taking to the skies, the Lockheed L10-11, the DC-10 and the jumbo jet that started it all, the 400 plus seat Boeing 747. Turbulence from the wing vortices of these enormous airplanes could and sometimes did upset the flight of airplanes nearby.
But as Widnall’s MIT colleague Dave Darmofal, the Jerome C. Hunsaker Professor of Aeronautics and Astronautics, notes, there was a smaller phenomenon in Widnall’s research that had even larger applications for wing, engine and rocket design. “Yes, she made an impact in understanding the wing tip vortex with the obvious aviation application, but the fundamental understanding of the Widnall instability you see in many more situations,” Darmofal says. “With any kind of fluid motion this instability plays a role.”
Widnall also kept an analytical eye on how MIT and other academic institutions could contribute their research expertise to government policy. Transportation was evolving in the seventies. America’s interstate highway system was brand new, but the increasing emphasis on cars had many environmental and social consequences, not all of them positive. Could academia help government think through these issues?
Widnall got the chance to find out when fellow engineering professor Robert Cannon asked her to be the first director of the office of university research for the U.S. Department of Transportation. In the early seventies, Widnall oversaw the distribution of $6.5 million, ($31 million in 2020 dollars) for university research projects from Alaska to Atlanta.
Around this same time, Widnall was thinking about improving outcomes for MIT students who came to the Institute without strong backgrounds in engineering, and who ultimately missed out on careers in this area. She teamed up with MIT physicist and electrical engineer Mildred “Millie” Dresselhaus to spearhead a new course for first-year MIT students that introduced avenues for career advancement in various engineering fields. “We had hoped for 15 students per semester, but we got over 100,” Widnall recalled in 2017. “Many MIT women and minority students took the course, and quite a few decided to major in engineering.”
Later, Widnall saw how MIT’s own research provided a way through the persistent gender imbalance in admissions. In the 1980s, as chair of MIT’s admission committee, she proposed a simple solution: accept more of the women who apply to MIT. Her proposal relied on the research of then-engineering professor Art Smith. He had discovered that the Scholastic Aptitude Tests under-predict the actual academic performance of women students — at least as far as the math scores were concerned. The proposal, based on the data, was to add a small percentage to their SAT score.
MIT had been casting about for ways to increase the number of women while at the same time using an irrelevant barrier. “People in the administration were saying, ‘We have to do more advertising we have to do more searching” for women students, Widnall says. “And I said, ‘Why are we searching? The women we should admit are the women who have applied.’”
The idea was effective. A year later, she says, “the number of women admitted rose from 26 percent to 38 percent.”
Not satisfied to stop at undergrad admissions, Widnall turned her attention to graduate applicants.
Daniel Hastings, the Cecil and Ida Green Professor of Education and head of the Department of Aeronautics and Astronautics, remembered Widnall’s presence at a meeting of faculty for admissions in the early 1990s. When all the candidates had been considered, the applications sat on the table, divided into stacks of yes, no, and waitlist. Then Widnall summarized the proceedings, noting that all of the women had been waitlisted while they accepted many of the men.
“Every time there was a question, ‘Is this candidate capable?’ the men were given the benefit of the doubt and the women were not. The women went to the waitlist pile,” says Hastings. “We felt collectively ashamed and we went back to correct that.”
Hasting’s summary was simple. “Wise people are the backbone of this place.”
Leadership on a national stage
Her reputation for wise sensibility was not confined within MIT’s walls. In 1993, U.S. President Bill Clinton cited Widnall’s scientific achievements when he nominated her to become secretary of the U.S. Air Force. Prior to the nomination, Widnall had served on several Air Force advisory boards and had served as chair of the Air Force Academy’s Board of Visitors in the 1980s. Accepting Clinton’s nomination, she became the first woman to lead a branch of the U.S. military.
While Widnall called it “an incredible experience,” to lead the Air Force, with an $84 billion budget, it was a time of international strife as well as domestic controversies and sexual harassment scandals, all of which were serious business. “Many pressures are brought on the secretary of the Air Force. The person has to make the tough calls and live with the key decisions,” says a successor to Widnall, 23rd Air Force Secretary Deborah Lee James.
When she announced she would return to MIT in 1997, Widnall’s legacy at the Air Force was writ large and small. On the larger side is a program to develop the expendable launch vehicle used for Atlas 5 and Delta 4 rockets, which began under her direction. “These vehicles still provide the majority of the launch capability for National Security launches,” she says, adding, “There has never been a launch failure.”
Less obvious, but equally important, was her contribution to defining the character of the Air Force. The branch had no stated core values when Widnall arrived, so she elevated those of the Air Force Academy — “Integrity first. Service before self. Excellence in all we do.” — to define all 400,000 airmen and women.
“If you ask any airmen, ‘What are our values?’ my guess is 99 percent would be able to tell you,” says Heather Wilson, who became the 24th Air Force secretary two decades after Widnall broke the glass ceiling. “The best values are those when a leader says, ‘This is who we are.’”
Back to the Tech
Widnall’s return to campus was a thrilling development for MIT’s ROTC students because she volunteered to be their academic advisor.
“It was awesome,” says 1st Lt. John Graham, now an F-16 pilot. Graham found his highly accomplished advisor down-to-Earth, fun-loving, and — most important — a talented instructor.
“What she taught me I wouldn’t have learned in a different astrodynamics class,” Graham says. “She could simplify the complex.”
Meanwhile, Widnall’s service continued on the national level. Most recently she served as co-chair of a 2018 report by the National Academies of Sciences, Engineering, and Medicine that examined the costs and consequences of sexual harassment in these fields. It was another example of Widnall applying her experience and intellectual energy to improve the environment for female students.
Among other things, the book-length report analyzes the effectiveness of harassment awareness training programs and finds them wanting. The report concludes changing behavior is key, and efforts should be regularly assessed.
“Schools have to create a climate that supports proper behavior,” Widnall says. “They don’t do it by passing rules and regulations; they change the environment.”
To Capt. Jay Pothula ’14, a former ROTC student at MIT, this message was clear: He and all students have a role to play in creating an atmosphere conducive to achievement. “Adhering to the core values is one way we can reduce the incidents of harassment and assault,” says Pothula, now in F-15 pilot training at Seymour Johnson Air Force Base in North Carolina.
Widnall also had a unique approach to testing students, according to Pothula, who took her aerodynamics class.
“Most of the quizzes and learning moments took place in knowledge tests,” he says. “You would go into a room with her and the teaching assistant and you would be given a problem and you would try to solve it in front of them.”
At first, Pothula found the method intimidating but before long his thoughts were flying. “These were great experiences because she would always know the right thing to say to push you ever so slightly in the right direction. She would always get you there. There was a dual purpose, testing your knowledge but you would learn a lot in the experience.”
Widnall did not reserve that kind of thought-prodding for students only. Olivier de Weck, professor of aeronautics and astronautics and of engineering systems, joined the faculty of MIT in 2001, occupying an office across the hall from Widnall, who he describes as a friend, colleague, and mentor. He hadn’t been in the job long when Widnall was asked to serve on the board looking into the loss of the space shuttle Columbia, which came apart on its return to Earth in February 2003, killing seven astronauts.
Over the course of seven months, Widnall and her fellow investigators examined the physical chain of events as well as the systemic pressures that played a role. De Weck watched in fascination as his colleague participated in writing one of the best-ever analyses of an accident.
“She is able to look under the covers,” he says describing Windall as having “an uncanny ability to peel away layers of complexity and get to the core reason about why things are and why they happen.”
It was de Weck’s habit to stop by Widnall’s office most mornings for a quick conversation or to catch up on MIT news. On occasion, though, de Weck would seek her advice. Widnall would steer the search for a solution right back to him, de Weck says, using her decades of experience to provide relevant context.
“She never tells you what to do, just how to look at the question from a holistic perspective,” de Weck says. “After leaving Sheila’s office, I felt I had a different way to think about the problem.”
When Widnall naively stepped onto the campus of MIT in 1956, she began a journey that would help her live up to the expectations of those who saw her potential in her youth and pushed her to do more. She became a role model for those who came after, inspiring those who benefited from her pioneering efforts for women and for science.
All the while she was becoming what she set out to be at the age of 15, considering that chunk of uranium; a traveler on a never-ending journey along the border between the known and the unknown.