Hsue-shen Tsien (PhD 1939; student of von Kármán) Assistant Professor of Aeronautics, 1943–1946; Robert H. Goddard Professor, 1949–1955. Director of the Guggenheim Jet Propulsion Center, 1949–1955. Scientist who was von Kármán's protégé, colleague, and heir-apparent. Became the first Director of the Daniel and Florence Guggenheim Jet Propulsion Center established at Caltech in 1949. Seminal work in many areas, including aeronautics, applied mechanics, rocketry, and control. Discovered similarity laws of hypersonic flow; designed GALCIT's first supersonic tunnel. Was instrumental in advising the U.S. military during WWII. Sadly, Tsien was forced to leave the U.S. in 1955; subsequently played a key role in developing Chinese missile research. In addition, he is widely considered the father of the modern Chinese space program.