The Tsyklon (Ukrainian: Циклон, "Cyclone", also known as Tsiklon), GRAU index 11K67, was a Soviet-designed expendable launch system, primarily used to put Cosmos satellites into low Earth orbit. It is based on the R-36 intercontinental ballistic missile designed by Mikhail Yangel and made eight launches, with seven successes and one failure. All of its launches were conducted from LC-90 at the Baikonur Cosmodrome. It is sometimes designated Tsyklon-2A, not to be confused with the later Tsyklon-2 rocket. It was introduced in 1967 and was derived from the R-36 ICBM (NATO designation SS-9 Scarp). It was retired in 1969.

It made its maiden flight on 27 October 1967. The booster's design was kept secret and no images or film clips of the complete vehicle were released to the public until after the collapse of the Soviet Union, in part because of being used exclusively for military payloads and also because it was derived from an actively serving missile system. After 1991, the plant where the R-36/Tsyklon were manufactured ended up in newly independent Ukraine.

Tsyklon was designed by the Yuzhnoye Design Bureau and manufactured by Yuzhmash (both in Dnipropetrovsk, Ukraine). Control system was designed at NPO "Electropribor"^[1] (Kharkiv, Ukraine). The last flown derivative, the Tsyklon-3 was retired in January 2009.^[2] Another derivative, the Tsyklon-4, continued to be developed after the retirement of Tsyklon-3, but the Tsyklon-4 project was cancelled in 2015 due to financial concerns. Tsyklon-4 never reached launch pad. However, yet another derivative, the Cyclone-4M, a development of Tsyklon-4, continued to be developed and is still currently (2021) under development.

Two rockets were derived from the Tsyklon: the Tsyklon-2 and Tsyklon-3, known respectively as the SL-11 and SL-14 by the United States DoD.^[3]

• Comparison of orbital launchers families

• Yuzhnoye Design Office
• Alcântara Cyclone Space