Sixty years ago, on November 29, 1961, Enos became the first chimpanzee to orbit the Earth. He flew on NASA’s Mercury-Atlas 5 (MA-5) mission, which the relatively new space agency deemed necessary before orbiting an astronaut in a Mercury capsule. But Enos is little remembered today. Ham, his compatriot from the U.S. Air Force’s chimp training facility in New Mexico, overshadows him. Launched on Mercury-Redstone 2 on January 31, 1961, Ham made a publicity splash after NASA stipulated his short, suborbital trip, which NASA required before the United States could put its first person in space. Doctors had a lot of (exaggerated) concerns about the impact of spaceflight on the human body and psyche; engineers wanted to prove the safety of the Mercury capsule. Ham, who was visibly agitated by his rough flight and by the flashing press cameras afterward, became a celebrity.