Qian Xuesen (; December 11, 1911October 31, 2009; also spelled as Tsien Hsue-shen) was a Chinese aerospace engineer and cyberneticist who made significant contributions to the field of aerodynamics and established engineering cybernetics. He achieved recognition as one of America's leading experts in rockets and high-speed flight theory prior to being deported to China in 1955. This occurred after having been accused of Communist sympathies — without evidence — during the Red Scare.
Qian received his undergraduate education in mechanical engineering at National Chiao Tung University in Shanghai in 1934. He traveled to the United States in 1935 and attained a master's degree in aeronautical engineering at the Massachusetts Institute of Technology in 1936. Afterward, he joined Theodore von Kármán's group at the California Institute of Technology in 1936, received a doctorate in aeronautics and mathematics there in 1939, and became an associate professor at Caltech in 1943. While at Caltech, he co-founded NASA's Jet Propulsion Laboratory. He was recruited by the United States Department of Defense and the Department of War to serve in various positions, including as an expert consultant with a rank of colonel in 1945. He became an associate professor at MIT in 1946, a full professor at MIT in 1947, and a full professor at Caltech in 1949.
During the Second Red Scare in the 1950s, the United States federal government accused him of communist sympathies. In 1950, despite protests by his colleagues and without any evidence of the allegations, he was stripped of his security clearance. He was given a deferred deportation order by the Immigration and Naturalization Service, and for the following five years, he and his family were subjected to partial house arrest and government surveillance in an effort to gradually make his technical knowledge obsolete. After spending five years under house arrest, he was released in 1955 in exchange for the repatriation of American pilots who had been captured during the Korean War. He left the United States in September 1955 on the American President Lines passenger liner SS President Cleveland, arriving in mainland China via Hong Kong.
Upon his return, he helped lead development of the Dongfeng ballistic missile and the Chinese space program. He also played a significant part in the construction and development of China's defense industry, higher education and research system, rocket force, and a key technology university. For his contributions, he became known as the "Father of Chinese Rocketry" and was nicknamed the "King of Rocketry". He is recognized as one of the founding fathers of Two Bombs, One Satellite.
In 1957, Qian was elected an academician of the Chinese Academy of Sciences. He served as a Vice Chairman of the National Committee of the Chinese People's Political Consultative Conference from 1987 to 1998.
He was the cousin of engineer Hsue-Chu Tsien, who was involved in the aerospace industries of both China and the United States. He is a cousin of the father of Roger Y. Tsien, the 2008 winner of the Nobel Prize in Chemistry.
Early life and education Qian was born in the Shanghai International Settlement, with ancestral roots in Lin'an, Hangzhou, in 1911. His parents were Qian Junfu and Zhang Lanjuan. He graduated from the High School Affiliated to Beijing Normal University, and attended Shanghai Jiaotong University. There, he received a bachelor's degree in mechanical engineering with an emphasis on railroad administration in 1934. He interned at Nanchang Air Force Base.
After graduating from college, Qian was admitted to the Boxer Indemnity Scholarship program, enabling him to study in the United States. He left China in August 1935, and went to the Massachusetts Institute of Technology (MIT) for a master's program in mechanical engineering. He received a Master of Science in aeronautical engineering from MIT on December 18, 1936. His master's thesis was titled Study of the turbulent boundary layer.
While at MIT, Qian was influenced by the methods of American engineering education, especially its focus on experimentation. This was in contrast to the contemporary approach practiced by many Chinese scientists, which emphasized theoretical elements rather than direct experience. Qian's experiments included plotting of pitot pressures using mercury-filled manometers.
Theodore von Kármán, Qian's doctoral advisor, described their first meeting:
Kármán made his home a social scene for the aerodynamicists of Pasadena, and Qian was drawn in: "Tsien enjoyed visiting my home, and my sister took to him because of his interesting ideas and straightforward manner."
Shortly after arriving at the California Institute of Technology in 1936, Qian 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". Qian received a Doctor of Philosophy in aeronautics and mathematics from Caltech on June 9, 1939. His doctoral dissertation was titled Problems in motion of compressible fluids and reaction propulsion.
Qian and von Kármán developed the Kármán-Tsien (Kármán-Qian) rule for estimating compressibility effects of subsonic flow in the field of fluid mechanics.
Career in the United States In 1943, Qian and two other members of their rocketry group drafted the first document to use the name Jet Propulsion Laboratory. In response to the German V-1 cruise missile and V-2 rocket, he and other important US scientists developed a variety of highly effective missiles that were vital in the closing stages of World War II.
Qian's mentor at Caltech, Theodore von Kármán, invited Qian to join the Air Force Scientific Advisory Group in 1945. In 1945, as an Army colonel with a security clearance, Qian was sent to Germany to investigate laboratories and question German scientists, including Wernher von Braun, and "to recruit German scientists for the American missile program".
Von Kármán wrote of Qian, "At the age of 36, he was an undisputed genius whose work was providing an enormous impetus to advances in high-speed aerodynamics and jet propulsion." During this time, he worked on designing an intercontinental space plane, which would later inspire the X-20 Dyna-Soar, a precursor to the American Space Shuttle.
Qian married Jiang Ying, a famed opera singer and the daughter of Jiang Baili and his wife, Japanese nurse Satô Yato. The elder Jiang was a military strategist and adviser to Kuomintang leader Chiang Kai-shek. The Qians were married on September 14, 1947 in Shanghai, and had two children; their son Qian Yonggang (, also known as Yucon Qian) was born in Boston on October 13, 1948, while their daughter Qian Yongzhen () was born in early 1950 when the family was residing in Pasadena, California.
Shortly after his wedding, Qian returned to America to take up a teaching position at MIT. Jiang Ying would join him in December 1947. In 1949, with the recommendation of von Kármán, Qian became a Robert H. Goddard Professor of Jet Propulsion at Caltech. He was also appointed the first director of the Daniel and Florence Guggenheim Jet Propulsion Center at Caltech.
In 1947, Qian was granted a permanent resident permit, and in 1949, he applied for naturalization, although he could not obtain citizenship. Years later, his wife Jiang Ying said in an interview with Phoenix Television that Qian did not apply for naturalization at all.
Detention By the early 1940s, U.S. Army Intelligence was already aware of allegations that Qian was a communist, but his security clearance was not suspended until prior to the Korean War. On June 6, 1950, the Army abruptly revoked Qian's security clearance, and he was questioned by the FBI. Despite support from his colleagues and no proof of the allegations, he received a deferred deportation order from the Immigration and Naturalization Service, and for the following five years, he and his family were subjected to partial house arrest and government surveillance intended to undermine his technical expertise. Two weeks later, Qian announced that he would resign from Caltech.
While at Caltech, Qian had secretly attended meetings with J. Robert Oppenheimer's brother Frank Oppenheimer, Jack Parsons, and Frank Malina that were organized by the Russian-born Jewish chemist Sidney Weinbaum and called Professional Unit 122 of the Pasadena Communist Party. Weinbaum's trial commenced on August 30 and both Frank Oppenheimer and Parsons testified against him. Weinbaum was convicted of perjury and sentenced to four years. Qian was taken into custody on September 6, 1950, for questioning and for two weeks was detained at Terminal Island, a low-security United States federal prison near the ports of Los Angeles and Long Beach. According to Theodore von Kármán's autobiography, when Qian refused to testify against his old friend Sidney Weinbaum, the FBI decided to launch an investigation on Qian.
In August, Qian spoke with Dan A. Kimball, the United States Under Secretary of the Navy at the time, whom he knew personally. During their conversation, Qian described the FBI visits and the indignity of losing his security clearance, even breaking down in tears. Kimball, determined to help, referred Qian to a lawyer in Washington, DC, to assist him in having his security clearance restored. Qian intended to return to China to resolve family issues and later come back to the United States, but Kimball preferred that Qian remain in the US.
After the packing company moving Qian's belongings to mainland China informed U.S. Customs that some of Qian's documents were marked "Secret" and "Confidential," U.S. officials raided the packing company's warehouse in Pasadena, California. The U.S. Immigration and Naturalization Service issued a warrant for Qian's arrest on August 25. Qian stated that all classified documents were locked in a cabinet in his office, and he gave the keys to a colleague, Clark Blanchard Millikan. In a press statement, Qian clarified, "There are some drawings and logarithm tables, etc., which someone might have mistaken for codes. I wished to take my personal notes, many of which were merely lecture notes, and other material with me for study while I was gone. I most certainly was not attempting to take anything of a secret nature with me or trying to leave the country in any but the accepted manner." The material included "newspaper, magazine, and scientific journal clippings on the U.S. atomic energy program" and news clippings about the trials of those charged with atomic espionage, such as Klaus Fuchs. Subsequent examination of the documents showed they contained no classified material. Various agencies, such as The United States Atomic Energy Commission, noted that the information held by Qian was unclassified information and did not pose a threat to national security. They further explained that the technical papers in Qian's collection were either outdated or authored by him, and that all the documents he had were characteristic of those held by top experts in the fields of aircraft and missile design.
On April 26, 1951, Qian was declared subject to deportation and forbidden from leaving Los Angeles County without permission, effectively placing him under house arrest.