Enos, a chimpanzee trained by NASA, was launched into space aboard the Mercury spacecraft, known as Mercury-Atlas 5. This mission, which occurred on November 29, 1961, marked a significant milestone in the American space program as Enos became the first chimpanzee to orbit the Earth. Previous missions had tested the effects of suborbital flights on chimpanzees, but Enos's journey was the first to involve a full orbital flight, making it crucial for understanding the impacts of space travel on biological subjects. The spacecraft orbited the Earth twice before successfully splashing down in the Atlantic Ocean off the coast of Puerto Rico, where it was recovered by the U.S. Navy. Enos's journey lasted about 2 hours and 28 minutes and included several significant milestones, including the successful execution of pre-programmed tasks that demonstrated his ability to handle the conditions of space travel. Enos's training involved complex behavioral conditioning, and he was able to perform multiple tasks such as pushing buttons in response to visual signals during the flight. His mission yielded important data that helped pave the way for future manned space missions.