On Nov. 3, 1957, Laika became the first animal to orbit Earth when she launched aboard the Soviet spacecraft Sputnik 2. A three-year-old stray from Moscow, she was selected for the space program because of her small size and calm temperament.
The mission was designed as a one-way trip: Soviet engineers had not built a system to return Laika to Earth. Sputnik 2 carried limited supplies of oxygen and food and launched from the Baikonur Cosmodrome in Kazakhstan on a rocket of the same type used to send the first Sputnik satellite into space.
Laika survived the launch and reached orbit, but died shortly afterward when the spacecraft overheated. Its heat shield had broken off, and the rising temperature killed her before oxygen deprivation or starvation could.
Laika was among the animals used in early spaceflight tests. Some animals survived their missions: Ham, a chimpanzee, lived through a 1961 test flight and was given his name after his safe return was confirmed.
Sources: Space.com.