of liquid-fueled rocket engines to propel airplanes. This led to contact with Zander, and sparked his interest in space exploration and rocketry. Group for the Study of Reactive Motion (GIRD) Practical aspects built on early experiments carried out by members of the 'Group for the Study of Reactive Motion' (better known by its Russian acronym "GIRD") in the 1930s, where Zander, Korolev and other pioneers such as the Russian engineers Mikhail Tikhonravov, Leonid Dushkin, Vladimir Vetchinkin and Yuriy Pobedonostsev worked together. On August 18, 1933, the Leningrad branch of GIRD, led by Tikhonravov, launched the first hybrid propellant rocket, the GIRD-09, and on November 25, 1933, the Soviet's first liquid-fueled rocket GIRD-X. Reactive Scientific Research Institute (RNII) In 1933 GIRD was merged with GDL by the Soviet government to form the Reactive Scientific Research Institute (RNII), which brought together the best of the Soviet rocket talent, including Korolev, Langemak, Ivan Kleymyonov and former GDL engine designer Valentin Glushko. Early success of RNII included the conception in 1936 and first flight in 1941 of the RP-318 the Soviets first rocket-powered aircraft and the RS-82 and RS-132 missiles entered service by 1937, which became the basis for development in 1938 and serial production from 1940 to 1941 of the Katyusha multiple rocket launcher, another advance in the reactive propulsion field. RNII's research and development were very important for later achievements of the Soviet rocket and space programs. During the 1930s Soviet rocket technology was comparable to Germany's, but Joseph Stalin's Great Purge severely damaged its progress. In November 1937, Kleymyonov and Langemak were arrested and later executed, Glushko and many other leading engineers were imprisoned in the Gulag. Korolev was arrested in June 1938 and sent to a forced labour camp in Kolyma in June 1939. However, due to intervention by Tupolev, he was relocated to a prison for scientists and engineers in September 1940. World War II During World War II rocketry efforts were carried out by three Soviet design bureaus. RNII continued to develop and improve solid fuel rockets, including the RS-82 and RS-132 missiles and the Katyusha rocket launcher, where Pobedonostsev and Tikhonravov continued to work on rocket design. In 1944 RNII was renamed Scientific Research Institute No 1 (NII-I) and combined with design bureau OKB-293, led by Soviet engineer Viktor Bolkhovitinov, which developed, with Aleksei Isaev, Boris Chertok, Leonid Voskresensky and Nikolay Pilyugin a short-range rocket powered interceptor