This Day in History: , Armstrong Walks on Moon.
July 20, 1969.
More than a billion people were listening when Armstrong uttered those immortal words: "That's one small step for man, one giant leap for mankind.".
Moments after his left foot became the first to touch the lunar surface, Armstrong was joined by "Buzz" Aldrin.
Two hours later, both men were back in the lunar module, the "Eagle." They slept on the moon, before rejoining the command module.
Getting astronauts to the moon was the biggest non-military human effort in Earth's history.
It cost $24 billion, involving more than 400,000 people.
Other missions to the moon followed.
Human beings have not set foot on the moon since 1972