The Apollo program was a human spaceflight program unertaken by NASA during the years 1961 – 1975 with the goal of conducting manned moon landing missions. President John F. Kennedy announced this goal in 1961, and it was accomplished on July 20, 1969 by Neil Armstrong and Buzz Aldrin during the Apollo 11 mission. Five other Apollo missions also landed astronauts on the Moon, the last one in 1972. These six Apollo spaceflights are the only times humans have landed on another celestial body. The Apollo program, specifically the lunar landings, are often cited as the greatest achievement in human history.