shortly after arriving at caltech in 1936, tsien became fascinated with the rocketry ideas of frank malina, other students of von kármán, and their associates, including jack parsons. along with his fellow students, he was involved in rocket-related experiments at the guggenheim aeronautical laboratory at caltech. around the university, the dangerous and explosive nature of their work earned them the nickname "suicide squad." tsien received his phd from caltech in 1939.