When were animals sent up in space?

In 1957, the first animal, a small female dog named Laika, was launched aboard the Soviet Sputnik 2. Laika was placed in a pressurized compartment within a capsule that weighed 1,103 pounds (500 kilograms), and died after a few days in orbit. The United States send a squirrel monkey named Old Reliable into space aboard the December 12, 1958, Jupiter flight, but it drowned during recovery. The next year, on another Jupiter flight, NASA sent two female monkeys into space and both were recovered alive.