On 20 July 1969, the world watched in awe and disbelief as U.S. astronaut Neil Armstrong slowly bounced across the moon’s surface. It was one small step for man and one giant leap for project management.

Long before NASA launched that 6.2-million-pound (2.8-million-kilogram) rocket and capsule, the U.S. space agency’s astronauts and mission control specialists went through bruising physiological and psychological testing, technical training and mission simulations. The repetition helped them identify and prepare for potential danger from blastoff to splashdown.

Anything less than flawless execution could have meant deadly consequences. Just two years before, three astronauts were killed during a launch rehearsal in a command module, leading NASA to make 125 design and safety changes that helped ensure Apollo 11’s success. Nearly every system and procedure required a backup, and even systems that passed with flying colors still went through second-party audits. A problem-solving matrix ensured a troubleshooting protocol existed for any scenario.

As NASA chief historian Roger D. Launius put it: “It may be that the most lasting legacy of Apollo was human: an improved understanding of how to plan, coordinate and monitor the myriad technical activities that were the building blocks of Apollo.”

1970

USSR’s Lunokhod 1 delivers the first robotic rover to explore the moon.

1973

U.S. module Mariner 10 studies the moon en route to Mercury and Venus.

1990

The Hiten orbiter becomes Japan’s first moon mission.

2003

The European Space Agency launches its first moon mission, SMART-1.

2007

China launches its first lunar mission, Chang’e 1.

2008

India launches its first lunar probe, Chandrayaan-1.