Mikhail Tikhonravov was the chief theoretician of the Soviet space program. Tikhonravov graduated from the Zhukovsky Air Force Academy in 1925 and subsequently became an expert in the field of aircraft engineering. Beginning in 1933, he began work with Sergei Korolev to solve the problems of rocket design for space exploration. In concert they developed the first liquid propellant engine rocket, and Tikhonravov continued to work on the design until Korolev's death in 1966. He also spent much of his time during this period educating rocket specialists about the design and its capabilities and limits. Shortly before his death in 1974, Tikhonravov was awarded several of the Soviet Union's highest civilian honors, including the Orders of Lenin and Red Banner of Labor, the title "Hero of Socialist Labor," and the Lenin Prize.