Tsien Hsue-shen (simplified Chinese: 钱学森; traditional Chinese: 錢學森; pinyin: Qián Xuésēn; born December 11, 1911) is a scientist who was a major figure in the missile and space programs of both the United States and People's Republic of China. NASA documents commonly refer to him as H.S. Tsien.
Tsien was a co-founder of the Jet Propulsion Laboratory at the California Institute of Technology, and became the "Father of Chinese Rocketry" (or "King of Rocketry") when he returned to China after being accused of being a communist by the United States government during the red scare of the 1950s.
In 1936 Tsien Hsue-shen went to the California Institute of Technology to commence graduate studies on the referral of Theodore von Kármán. Tsien obtained his doctorate in 1939 and would remain at Caltech for 20 years, ultimately becoming the Goddard Professor and establishing a reputation as one of the leading rocket scientists in the United States.
In 1943, Tsien and two others in the Caltech rocketry group drafted the first document to use the name Jet Propulsion Laboratory; it was a proposal to the Army to develop missiles in response to Germany's V-2 rocket. This led to the Private A, which flew in 1944, and later the Corporal, the WAC Corporal, etc.
Soon after Tsien applied for U.S. citizenship in 1950, allegations were made that he was a communist and his security clearance was revoked. The Federal Bureau of Investigation located a 1938 US Communist Party document with his name on it. Tsien found himself unable to pursue his career and within two weeks announced plans to return to mainland China.