1961: Chimpanzees
The DNA of chimpanzees more closely resembles human DNA than monkey DNA, so sending a chimp into space was pivotal in preparing to launch a human into space.
On January 31, 1961, HAM the Chimpanzee (short for Holoman Aerospace Medical Center) became that first chimp in space (shown), just three months before Alan Shepard became the first American human in space.
Nine months later, on November 29, 1961, Enos the Chimp became the first to orbit the earth.
