Apollo 11

Apollo 11 launched from Kennedy Space Center on July 16, 1969, and four days later the lunar module Eagle touched down in the Sea of Tranquility with about 30 seconds of fuel to spare. Neil Armstrong’s first step onto the surface — ‘one small step for a man, one giant leap for mankind’ — fulfilled the goal President Kennedy had set eight years earlier and was watched by an estimated 600 million people.

Armstrong and Buzz Aldrin spent 21 hours on the surface, collecting 47.5 pounds of lunar samples and deploying science instruments, while Michael Collins orbited above in the command module Columbia. The mission’s success rested on a decade of engineering: the Saturn V’s 7.6 million pounds of thrust, the lunar module’s fragile descent engine, and the pinpoint navigation that brought all three astronauts home to a Pacific splashdown on July 24.