Leaving the Cradle

The countdown at Cape Kennedy reached zero at 9:32 in the morning on July 16, 1969. Five F-1 engines ignited beneath the Saturn V rocket, each burning more fuel per second than a Formula 1 car uses in an entire race. The flames were controlled explosions, kerosene and liquid oxygen meeting at thousands of degrees, producing seven and a half million pounds of thrust. The entire structure, taller than a football field is long, lifted slowly into the Florida sky.

Inside the command module at the very top, three men felt the world fall away. Neil Armstrong, the mission commander. Buzz Aldrin, the lunar module pilot. Michael Collins, who would remain in orbit while the other two descended to the surface. They sat in couches custom-molded to their bodies, wearing pressure suits designed to keep them alive in a vacuum. The cabin around them was smaller than a van. They would live in it for eight days.

Apollo 11 was not the first spacecraft to leave Earth orbit. The Soviets had sent probes to the Moon. NASA had already completed Apollo 8, which circled the Moon on Christmas Eve 1968 and sent back the photograph of Earthrise. But Apollo 11 carried landing gear, a descent engine, and a ladder. This time, they were planning to walk.

The design challenges were extraordinary. Everything had to work the first time, 240,000 miles from the nearest mechanic. The lunar module, which Armstrong and Aldrin would pilot to the surface, was so fragile you could punch through its skin with a screwdriver. It had to be that light. Weight was everything. Every ounce on the Moon required exponentially more fuel on Earth.

apollo 11 launches from kennedy space center, july 16, 1969. source: wikimedia commons

The mission plan was a series of nested optimizations. Launching from Earth required the massive Saturn V. Reaching the Moon required only the much smaller command and service module. Landing required an even smaller lunar module. Returning from the surface required only the upper half of the lunar module, leaving the descent stage behind as a permanent marker. Then the lunar module would be jettisoned, and only the command module would return to Earth. Each stage was designed for a single purpose and then discarded, like Jacquard's punch cards executing a pattern one instruction at a time.

The numbers were precise to the second. The launch window lasted less than five hours. Launch too early or too late and the orbital mechanics would not align. The Moon moves. The Earth rotates. Everything is always in motion. Hitting a moving target from a moving platform while you are also moving requires calculation at a scale that feels absurd until you realize people actually did it.

the lunar module eagle, photographed from the command module in lunar orbit. source: wikimedia commons

Four days after launch, Armstrong and Aldrin would descend to the Sea of Tranquility while Collins orbited above, out of radio contact for 48 minutes each orbit. Collins would be the loneliest human being in existence during those blackouts, farther from any other person than anyone had ever been. He carried a list of 18 contingency procedures in case Armstrong and Aldrin could not lift off. If something went wrong, he would have to come home alone.

Nothing went wrong. On July 20, Armstrong stepped onto the surface. The lunar module's computer had guided them to a boulder field, and Armstrong took manual control, flying sideways until he found a clear patch of dust with just seconds of fuel remaining. Design under pressure. Humanity had built a machine capable of crossing a quarter million miles of vacuum, and in the final moments, it still required human judgment.

Apollo 11 returned safely on July 24. The command module splashed down in the Pacific, and three astronauts emerged into quarantine, just in case the Moon carried something alive. It did not. What it carried was proof that human beings could leave their planet and return. We built tools to escape the gravity well. We are, as far as we know, the only species that has ever done this. The cradle is optional.