Enos also wasn't the first animal to be launched into space by U.S. scientists. In 1947 scientists launched fruit flies into space, and these insects survived cosmic radiation and other spaceflight conditions.
Enos wasn't even the first chimp in space! That honor goes to Ham, who was launched into a sub-orbital spaceflight in 1961. He wasn't just a passenger; he pushed levers as he had been trained to do—and he was only a smidge slower than usual, down on Earth, so he proved that humans could perform tasks on a spaceflight.
No, Enos wasn't the first this or that or this other, but he was the first animal to achieve orbit on a U.S. spacecraft, and he was the first ever chimpanzee to achieve orbit.
Enos had more than 1,250 hours of training for his flight, including aircraft flights on which he encountered a certain amount of g force. And on this date in 1961, Enos flew into space on board Mercury Atlas 5. He was to complete three orbits.
Enos and the Mercury spacecraft completed the first orbit in one hour and 28 seconds. They completed a second orbit, but they were then brought back to Earth because the spacecraft was not maintaining altitude as it should.
Enos had a luckier ending than poor Laika. He survived splashdown and, when removed from his capsule, rescuers say that he jumped for joy and ran around the deck of the recovery ship, shaking their hands.
Here's an old movie clip about Enos and his flight. Unfortunately, we have no film of a joyful Enos shaking people's hands.
This much longer movie about chimp astronauts doesn't focus on Enos at all, but gives you a good idea of what training he had to undergo.
Also on this date: