Korabl-Sputnik 1, also known as Sputnik 4 in the West, was the first test flight of the Soviet Vostok programme, and the first Vostok spacecraft. It was launched on May 15, 1960. Though Korabl-Sputnik 1 was unmanned, it was a precursor to the first human spaceflight, Vostok 1. Its mass was 4,540 kilograms, of which 1,477 kilograms was instrumentation.
The spacecraft, the first of a series of spacecraft used to investigate the means for manned space flight, contained scientific instruments, a television system, and a self-sustaining biological cabin with a dummy of a man. It was designed to study the operation of the life support system and the stresses of flight. The spacecraft radioed both extensive telemetry and prerecorded voice communications. After four days of flight, the retro rocket was fired and the descent module was separated from its equipment module, but because the spacecraft was not in the correct flight attitude when its retro fired, the descent module did not reenter the atmosphere as planned.
The descent module re-entered the atmosphere on September 6, 1962, while the equipment module re-entered on October 15, 1965.