High Quality Content by WIKIPEDIA articles! The Vostok-K (Russian: Восток meaning "East"), GRAU index 8K72K was an expendable carrier rocket used by the Soviet Union for thirteen launches between 1960 and 1964, six of which were manned. It was derived from the earlier Vostok-L, however it featured uprated engines to improve performance, and enlarge its payload capacity. It was a member of the R-7 family of rockets.