Vostok: Elektron-3 &4

The Vostok-K was an expendable carrier rocket used by the Soviet Union for thirteen launches between 1960 and 1964, six of which were manned. 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.