Site 90 at the Baikonur Cosmodrome is a launch complex consisting of two pads, which has been used by UR-200, Tsyklon-2A and Tsyklon-2 rockets. Built in the 1960s for the UR-200, which was first launched from the complex on 3 November 1963,^[1] it was converted for use by Tsyklon rockets after further development of the UR-200 was cancelled. One pad is currently active, pending the final Tsyklon-2 launch which is expected to occur in 2012.

The two pads at the site are 90/19, which was the first to be used, and 90/20, which saw its first launch in September 1964. The last launch from Site 90/19 occurred on 9 December 1997, whilst 90/20 remains operational, its most recent launch having occurred in June 2006.^[2] In total, the complex has been used for 123 launches as of March 2012. These launches consisted of nine UR-200,^[3] eight Tsyklon-2A,^[4] and 106 Tsyklon-2 rockets.^[2] There is no data on which of the two pads was used for 74 of the Tsyklon-2 launches known to have originated from the complex, however it is known that twenty two launches, including six UR-200s and five Tsyklon-2As, occurred from Site 90/19, and 27 launches, including three UR-200s and three Tsyklon-2As, occurred from pad 90/20.^[1][2]

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