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 Vostok family of rockets.
|Country of origin||USSR|
|Payload to LEO|
|Mass||4,730 kilograms (10,430 lb)|
|Launch sites||Baikonur, Site 1/5|
|First flight||22 December 1960|
|Last flight||10 July 1964|
|People or cargo transported||Vostok|
|Powered by||1 RD-107-8D74-1959|
|Maximum thrust||970.86 kN|
|Total thrust||3883.4 kN|
|Burn time||118 seconds|
|Powered by||1 RD-108-8D75-1959|
|Maximum thrust||912 kN|
|Burn time||301 seconds|
|Powered by||1 RD-0109|
|Maximum thrust||54.5 kN|
|Burn time||365 seconds|
The Vostok-K made its maiden flight on 22 December 1960, three weeks after the retirement of the Vostok-L. The third stage engine failed 425 seconds after launch, and the payload, a Korabl-Sputnik spacecraft, failed to reach orbit. The spacecraft was recovered after landing, and the two dogs aboard the spacecraft survived the flight.
On 12 April 1961, a Vostok-K rocket was used to launch Vostok 1, the first manned spaceflight, which made Yuri Gagarin the first human to fly in space. All six manned missions of the Vostok programme were launched using Vostok-K rockets. The first two Zenit reconnaissance satellites were also launched with the Vostok-K, but it was soon replaced in that capacity with the uprated 8A92 booster. After the conclusion of the Vostok program, there were two remaining 8K72Ks left; these were used to launch four Elektron scientific satellites on 30 January and 10 July 1964.