Qian Xuesen, a Chinese citizen, Caltech professor and US Army Colonel, is seen here with his mentor, Hungarian-American scientist Theodore von Karman, and the latter's advisor, the German scientist Ludwig Prandtl, in 1945. Both Qian and von Karman were working for the U.S. Department of Defense and were dispatched to Europe to investigate German rocket programs in 1945. This honeymoon between China and the US was short-lived.