The Soviet Union launched Sputnik 2, carrying the space dog Laika as the first living creature to enter orbit around Earth.
Sputnik 2
Sputnik 2, or Prosteyshiy Sputnik 2, launched on 3 November 1957, was the second spacecraft launched into Earth orbit, and the first to carry an animal into orbit, a Soviet space dog named Laika.
Soviet space dogs
During the 1950s and 1960s the Soviet space program used dogs for sub-orbital and orbital space flights to determine whether human spaceflight was feasible. The Soviet space program typically used female dogs due to their anatomical compatibility with the spacesuit. Similarly, they used mix-breed dogs due to their apparent hardiness.
Laika
Laika was a Soviet space dog who was one of the first animals in space and the first to orbit the Earth. A stray mongrel from the streets of Moscow, she flew aboard the Sputnik 2 spacecraft, launched into low orbit on 3 November 1957. As the technology to re-enter the atmosphere had not yet been developed, Laika's survival was never expected. She died of hyperthermia hours into the flight, on the craft's fourth orbit.