The Apollo program, known as Project Apollo, was a pivotal series of missions organized by NASA to land humans on the Moon and bring them safely back to Earth. Spanning from 1961 to 1972, this program marked a significant period in space exploration history, achieving its most famous milestone with the Apollo 11 mission in 1969, when astronauts Neil Armstrong and Buzz Aldrin became the first humans to set foot on the lunar surface. The program not only demonstrated the capabilities of the United States in space but also contributed to a wealth of scientific knowledge and technological advancements.