Apollo

Apollo began in early 1960 as a follow-up to Project Mercury, named by NASA manager Abe Silverstein after the Greek god because it suited the program’s grand ambitions. It became a race to the Moon on May 25, 1961, when President John F. Kennedy asked Congress to commit the nation to landing a man on the Moon and returning him safely before the end of the decade.

The program suffered a tragic start when a fire during a ground test in January 1967 killed the Apollo 1 crew: Gus Grissom, Ed White and Roger Chaffee. After a redesign of the spacecraft, Apollo returned to flight in late 1968. Apollo 8 carried the first humans around the Moon that December, and on July 20, 1969, Apollo 11 landed Neil Armstrong and Buzz Aldrin on the Sea of Tranquility, meeting Kennedy’s goal. Five more landings followed. Apollo 13 had to abort its landing after an oxygen tank exploded on the way to the Moon, and the crew used the lunar module as a lifeboat to get home. The last three missions brought a battery-powered rover that let astronauts explore far from their landers.

Over 11 crewed flights, Apollo sent 24 astronauts to the Moon, landed 12 of them on its surface, and brought back about 382 kg of lunar rock and soil, which scientists are still studying today. At its peak, the program employed about 400,000 people, and it cost about $25.4 billion at the time (about $257 billion in 2026 adjusted for inflation). Budget cuts ended it early: Apollo 18 and 19 were canceled, and Apollo 20’s Saturn V instead launched the Skylab space station. Apollo 17, in December 1972, was the last time humans walked on the Moon.