The Apollo program was the third human spaceflight program undertaken by NASA, on behalf of the United States of America. Its goal — "...before this decade is out, of landing a man on the Moon and returning him safely to the Earth," (as U.S. President John F. Kennedy announced in 1961) — was accomplished on July 20, 1969, with the Apollo 11 landing of astronauts Neil Armstrong and Buzz Aldrin, and with Michael Collins orbiting above. To date, it is the only series of spaceflights to land humans on another world, and thus is widely respected and an inspiration for future spaceflights. The program used the Apollo spacecraft and Saturn launch vehicle, and was conducted during the years 1961 – 1975, with a total of six successful landings.
The later Skylab program and the joint American-Soviet Apollo-Soyuz Test Project used equipment originally produced for Apollo, and are often considered to be part of the overall Apollo program. As of 2007, there has not been any further human spaceflight beyond low earth orbit since the last mission in the Apollo program, Apollo 17.
Despite the many successes, there were two major failures, the first of which resulted in the deaths of three astronauts, Virgil Grissom, Ed White and Roger Chaffee, in the Apollo 1 launchpad fire (the mission designation was AS-204, which was renamed Apollo 1 to honor the astronauts and their widows). The second was an in-space explosion on Apollo 13, which badly damaged the spacecraft on the moonward leg of its journey. The three astronauts aboard narrowly escaped with their lives, thanks to the efforts of flight controllers, project engineers, backup crew members and the skills of the astronauts themselves.