Sputnik 2 carried Laika, the first animal to orbit Earth, in 1957.
The Soviet spacecraft launched on 3 November 1957, only a month after Sputnik 1. Its passenger was Laika, a stray dog selected for a mission designed to study whether a living creature could survive launch and weightlessness.
Sputnik 2 was not built to return to Earth, so Laika’s mission was one-way. Early Soviet reports claimed she survived for several days, but later evidence showed that overheating and stress probably killed her within hours. The spacecraft continued orbiting Earth until it reentered the atmosphere on 14 April 1958.
Laika is sometimes mistakenly described as the first animal in space. Earlier suborbital flights had carried animals above the atmosphere, but Sputnik 2 made her the first animal to complete an orbit. The mission helped demonstrate the biological challenges later human spaceflight programs had to solve.