Hsue-Shen Tsien, the first director of Caltech's Guggenheim Jet Propulsion Center, was later chairman of the Institute of Mechanics of the People's Republic of China's National Academy of Sciences, in Beijing. Born in Shanghai, Tsien received his BS in mechanical engineering from Chiao-Tung University. In 1935 he came to the United States, where he earned his MS from MIT. At Caltech he worked closely with Theodore von Karman on supersonic flight and jet propulsion and was awarded a PhD in aeronautics in 1939. He continued at Caltech as a research fellow, assistant professor, and associate professor, until he moved to MIT as their youngest full professor. During World War II Tsien was again associated with von Karman when he served as consultant on jet propulsion to Aerojet and the Scientific Advisory Board of the Air Forces. After the war the Air Forces commended him for his "invaluable contribution" to victory. In 1949 the Guggenheim Foundation offered him the directorship at one of their two research centers (at Caltech and Princeton) and in choosing Caltech, he became the Goddard Professor of Jet Propulsion. Tsien returned to China in 1955 and in that year became a member of the Chinese Academy of Sciences. Tsien passed away on October 31, 2009.