Enos was purchased from the Miami Rare Bird Farm in April of 1960. He completed more than 1250 hours of training for his mission at the University of Kentucky and Holloman Air Force Base. His training was more intense than Ham's because he would be exposed to weightlessness and high g-forces for longer periods of time. His training included psychomotor training and aircraft flights. Enos was selected to make the first orbital animal flight only 3 days before the launch. Two months before allowing a chimp to be launched into orbit, NASA had launched Mercury Atlas 4 on September 13, 1961 to conduct the same mission with a "crewman simulator" in the spacecraft. Enos flew into space on board Mercury Atlas 5 in November of 1961. He completed his first orbit in 1 hour and 28.5 minutes. Enos was originally scheduled to complete 3 orbits, but was brought back after the second orbit because the spacecraft was not maintaining proper attitude. Enos was glad to return to Earth. According to observers, Enos jumped for joy and ran around the deck of the recovery ship enthusiastically shaking the hands of his rescuers.