MIT professor emeritus Yao Tzu Li dies at 97

Champion of innovation sought to instill entrepreneurship in students.


Yao Tzu Li, professor emeritus in the Department of Aeronautics and Astronautics and co-founder of the MIT Man-Vehicle Laboratory, passed away suddenly Sunday, Aug. 14, of an aortic aneurysm. He was 97.

An energetic innovator and educator, Li encouraged students to explore their entrepreneurial spirit. In 1973, Li established the MIT Innovation Center, a program designed to shepherd students through the process of innovation, from developing an idea to engineering a prototype to marketing a product.

“It is a common belief that inventors and [entrepreneurs] are self-made men, born with that talent. Edison, the Wright brothers — none attended college,” Li told The Associated Press in 1973, shortly after launching the program. “But with limits on natural resources, environmental concern and the shrinking U.S. share of the world market, we simply cannot rely upon the self-breeding process of a few innovators to keep the rest of the educated engineers employed. What we need is an organized training ground for innovators and entrepreneurs.”      

Li was born in Peking on Feb. 1, 1914. After earning a bachelor’s degree from Peking University and a master’s degree from Central University in China, Li continued his studies in aeronautical engineering at MIT, where he received a master’s degree in 1938 and an ScD in 1939.

Shortly after earning his doctorate, Li returned to China, where he joined the Chinese Air Force as a chief engineer. In this capacity, Li oversaw the construction and operation of an airplane-engine manufacturing plant in Guizhou Province that was then being built underground. From 1945 to 1946, Li worked with the Chinese government to further advance aircraft technology, heading up development of the country’s first homegrown aircraft engine.

In 1947, Li made his way back to MIT, where he became a research associate in the Department of Aeronautics and Astronautics. From 1953 to 1957, Li directed the MIT Cruise Control Project in the Aerophysics Laboratory, where he worked with Charles Stark Draper to develop an automatic optimization system for the B-52 bomber.

Li became a full professor at MIT in 1961; around that time Draper paired him with a newly appointed assistant professor, Larry Young, to launch the Man-Vehicle Laboratory. Together, the two investigated the effects of air and space travel on human passengers, winning a grant from NASA to study the phenomenon of space sickness — particularly for astronauts in the early Apollo program.

Young, now the Apollo Program Professor of Aeronautics and Astronautics, remembers Li as a generous mentor and friend, and a born inventor. Young recalls a particular weekend in the 1960s when the two took a break from work to go skiing; Li had asked Young, an avid skier, for a lesson.

“We went up to Mount Sunapee … on a Friday,” Young says. By Monday, “he had gotten a pair of skis and had modified them by attaching an I-bolt to the back of the ski, and a little steel cable that went from the back of the ski up to a kind of harness up around his lower leg, so when he would lean forward, the ski would bend.”

The invention made turning easier: A skier would otherwise have to hop to switch directions, to prevent the back of the skis from catching in the snow. With Li’s contraption, a skier would simply have to lean into the turn.

“Only in the ’90s did the ski racers and ski manufacturers discover the ease and grace, as well as the speed, of the turn-by-leaning technique,” Young says. Li’s design “was foretelling the evolution of skis by a decade or more.”

Throughout his career, Li was a prolific inventor, with more than 60 patents to his name. In addition to patents for aircraft optimization systems and pressure indicators for rocket engines, Li patented designs for an archery bow and a tennis racket with flexibly anchored strings.

In 1972, shortly before launching the MIT Innovation Center, Li made national headlines with a particularly entrepreneurial idea: a scheme, as a Boston Globe article put it, to “tackle the tilt” of the Leaning Tower of Pisa. The idea started as a joke — Li made light of the tower’s tilt with his children, after hearing about the problem in the news. The joke turned into a project during a European tour, when Li dined with a professor then in charge of saving the tower.

Li came up with a blueprint to keep the tower from toppling, involving a ring of concrete pads surrounding the base of the tower to redistribute pressure and support the tower’s weight. The plan never gained traction, but Li, ever the entrepreneur, was unfazed. He simply moved on to his next project.

“He had an incredible way of looking at complex mechanical problems and getting to the heart of them,” Young recalls. “He was not inhibited by the conventional way of doing things.”

Li was predeceased in 2004 by his wife of 56 years, Nancy Tung Tuan Lin. He is survived by four children — Winifred and her husband William Oliver of Weston, Mass.; Karl and his wife Wei Xu of Millwood, N.Y.; Kenneth and his wife Valerie Ng of Piedmont, Calif.; and Wendy and her husband Jonathan Spector of Weston, Mass. — and 11 grandchildren: Jeffries, Parker and Alisan Oliver-Li; Lindsay, Nicholas, Jason and Jasmine Li; and Daniel, Michael, William and Benjamin Spector. He is also survived by his brother S.Y. and sister-in-law Lena Lee, as well as numerous cousins, in-laws, nieces and nephews.

A memorial service will be held at 10 a.m. Saturday, Sept. 3, in the MIT Memorial Chapel. In lieu of flowers, gifts may be made to the Yao T. Li (1939) Fellowship Fund, care of Bonny Kellermann, MIT Director of Memorial Gifts, 600 Memorial Drive (W98-500), Cambridge, Mass., 02139. Credit card gifts may be made at from the following secure website: https://giving.mit.edu/givenow/ConfirmGift.dyn?desig=3325000. Please click the button to indicate that your gift is in memory of Yao T. Li, alumnus/a.


Topics: Faculty, Obituaries

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