Running from 1961 through 1972, the Apollo Program was the NASA program that put American astronauts on the Moon. The program consisted of eleven spaceflights from Apollo 7 in 1968 through Apollo 17 in 1972. The first four of these spaceflights - Apollo 7 through Apollo 10 - were meant to test the equipment used for the program, with Apollo 8 being the first to orbit the Moon.

The final seven flights - Apollo 11 through Apollo 17 - were meant to land on the moon. Six of these seven missions successfully landed on the moon. Apollo 11 was the first mission to land on the Moon in 1969. Neil Armstrong became the first person to walk on the Moon and Buzz Aldrin the second. Michael Collins remained on the command module as the pilot in lunar orbit. The seventh mission intended to land on the Moon, Apollo 13 in 1970 had abort part of their mission due to an accident, but all astronauts returned safely to Earth.

AS-204 in 1967 was the first crewed mission of the Apollo program. During a launch test of the mission, a fire broke out in the cabin, and all astronauts died: Gus Grissom, Edward H. White, and Roger B. Chaffee. At the request of their families, NASA renamed AS-204 as Apollo 1.

External Sources:

Hitt, David, "What Was the Apollo Program?", NASA Knows! (Grades 5-8) series, NASA Educational Technology Services, https://www.nasa.gov/audience/forstudents/5-8/features/nasa-knows/what-was-apollo-program-58.html, accessed June 20, 2023.

Apollo-1 (204), NASA History Division, https://history.nasa.gov/Apollo204/, accessed June 20, 2023.