When Apollo 11 astronauts were traveling to the moon in July 1969, it required the invention and development of some truly groundbreaking technology. And it was all being produced at a furious pace, it was after all the Space War between The United States of America and the USSR.

We saw the invention of the world’s biggest rocket, the smallest one, fastest on and even the smallest computers at the time. Not to mention the operations needed high-speed data networks, spacesuits, space food, and a moon buggy. The issue was that during the 1960s, the manufacturing industry had not caught up with the technology that was being produced. This meant that things you would have believed were built using robotics and machinery, were assembled entirely by hand.

This meant there was a small force of crucial workers in NASA on Earth, some were so specialized they were guarded at all times by secret services. Because if they were ever captured or killed, then NASA’s billion-dollar operations would all be let down. You could think of these specialized manufacturing workers as a single point of failure for NASA, they were perhaps the most important assembly workers ever to exist on Earth.

Spacesuits were for example created by Playtex, bringing together 21 layers of nested fabric that needed to still be flexible enough to do all the work on the moon. Each layer was sewn by an expert, as each layer had to be assembled delicately and with immense precision.

Perhaps the most important part of a space mission? How to get home, back down to Earth safely. During the time of Apollo 11, they used parachutes, which were all 7,200 square feet of fabric, that is pretty much enough to cover the floor space of three typical U.S sized houses. The problem was only three people in the world knew how to fold them correctly for deployment. Only three people were trained by the Federal Aviation Administration to do this: Norma Cretal, Buzz Corey and Jimmy Calunga.

As a result, these three people were never allowed to ride in the same car or plane together, NASA feared so much that an accident could wipe out there knowledge of how to correctly fold an Apollo parachute.