Korabl-Sputnik 1

Korabl-Sputnik 1 (Russian: Корабль Спутник 1 meaning Ship Satellite 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. A bug in the guidance system had pointed the capsule in the wrong direction, so instead of dropping into the atmosphere the satellite moved into a higher orbit. The descent module re-entered the atmosphere on September 5, 1962. A piece was found in the middle of North 8th Street in Manitowoc, Wisconsin in the northern United States.

This 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. The spacecraft 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 descent module was separated from its equipment module and retrorockets were fired, but because of an incorrect attitude the spacecraft did not reenter the atmosphere as planned. The descent module re-entered the atmosphere on September 5, 1962, while the equipment module re-entered on October 15, 1965.

Giovanni Battista Judica Cordiglia, who set up his own amateur listening station at Torre Bert near Turin, is reported to claim that radio signals were received on November 28, 1960 which could have originated from this spacecraft; the spacecraft is known to have radioed prerecorded voice communications. It has led some to believe a conspiracy theory that the spacecraft may have been manned by the so-called lost cosmonauts.