On this day in 1969, 55 years ago to the day, Apollo 11 astronauts Neil Armstrong and Edwin “Buzz” Aldrin became the first people to walk on the moon. After landing their craft, known as the Lunar Excursion Module (LEM, later shortened to LM (Lunar Module)), they planted an American flag to commemorate the historic achievement (see video below). Armstrong and Aldrin remained on the lunar surface, spending bout two and a quarter hours together exploring the site they had named Tranquility Base upon landing. Armstrong and Aldrin collected 47.5 pounds of lunar material to bring back to Earth as pilot Michael Collins flew the Command Module Columbia in lunar orbit. They remained on the lunar surface for 21 hours, 36 minutes before blasting off, docking with another ship in orbit, and returning to earth three days later on July 24, 1969.  (Source: Wikipedia)

The Apollo program, also known as Project Apollo, was the United States human spaceflight program carried out by the National Aeronautics and Space Administration (NASA), which succeeded in preparing and landing the first men[2] on the Moon from 1968 to 1972. It was first conceived in 1960 during President Dwight D. Eisenhower's administration as a three-person spacecraft to follow the one-person Project Mercury, which put the first Americans in space. Apollo was later dedicated to President John F. Kennedy's national goal for the 1960s of "landing a man on the Moon and returning him safely to the Earth" in an address to Congress on May 25, 1961. It was the third US human spaceflight program to fly, preceded by the two-person Project Gemini conceived in 1961 to extend spaceflight capability in support of Apollo.