Some 40,000 technicians had to build the Apollo Command Module. It was in its day, the single most complex vehicle ever built. It had to withstand the forces of a massive Saturn V rocket, the pull of the Earth’s gravity, and the impact with the atmosphere at tens of thousands of miles an hour. It had to withstand the absolute zero temperates of space and the effulgent heat of re-entry. It had to house and hold three human beings with accommodations for hygiene, food, sleep, and work. And it had to house them for 15 days.
In 1961, the USSR was winning the space race. On April 12th, 1961, they were the first into space and the first to put a human being outside of the Earth’s atmosphere and his name was Yuri Gagarin. It wasn’t until July 22nd 1961 that Gus Grissom became the first American to slip the bonds of Earth and fly around her in a capsule called Mercury, named after the Greek God of Travel and Communication. Of course NASA had been at the edge of space in the new X-15 rocket which taught us a lot about the conditions of the outer atmosphere.
The problem with the Command Module was that if it were to really withstand takeover and re-entry forces it might have to be very heavy. That would translate into more fuel and heavier payloads in a project where very single pound was sacrosanct. So the NASA engineers came up with a very smart solution to the weight and power problem: split up the duties between the modules. There would be a service module that would hold all the engines and fuel and provide all the thrust – yet it could separate from the command module. So there would be the Command Module, and during Apollo 11, there would be a separate LEM, or Lunar Excursion Module. The SPS or Service Propulsion Module was the way to get the astronauts to the Moon and back home.
One of the tragedies of the Apollo mission was the sudden fire in the Apollo 6 command module during a test. One of the engineering feats was to put good air pressure inside the module that would help seal the door shut. The content of the atmosphere in the test module was pure oxygen. It never occurred to engineers that a single spark from the complex and labyrinthine series of wires would ignite an atmosphere of pure oxygen. The fire killed Gus Grissom, Ed White, and Roger Chaffee.
As a result the Apollo 7 module saw an atmosphere of 60% nitrogen.
The Apollo 6 fire set NASA back 18 months in a race with Russia to be the first to put a man on the moon and safely return him. This was a gauntlet thrown by John F Kennedy early in his presidency to achieve this by 1970.
Apollo 7 saw new and vast improvements in the Command Module. This vehicle was piloted by Wally Shirra, Donn Eisley and R. Walter Cunnigham. This would be the first time three human beings had left the Earth together.
Parachutes were some of the lowest technology utilized in the Apollo program, but they were mission critical. The parachutes that would cradle the module as it floated down into the atmosphere were the largest and best prepared parachutes in existence. They each took about a month to make. Each one had over a million stitches in it and a quarter of an acre of cloth. The three giant parachutes would slow the capsule from 25,000 miles an hour to 20 miles an hour in just 80,000 feet of free fall. At one point it was traveling at 36,000 feet per second. The heat was so great it blocked out the radio signal.
Apollo 8 was the attempt to put men outside the Earth’s orbit and put the three men, James Lovell, Bill Anders and Frank Borman around the Moon. This particular iteration of the Command Module ran on Fuel cells that could make water and make electricity and make thrust quite efficiently, and thusly solved the problems of heavy batteries. The Command Module crew experienced the sharp drop in temperature once they made a 45 minute transit around the dark side of the Moon. But they emerged from the Dark Side unfazed. They put the module through every test they could and paved the way for the ultimate trip in history: the Moon Walk.