it is viewed as today, NASA was barely a toddler when Kennedy made his announcement. It had only been created three years earlier.
NASA’s attempt to put humans on the Moon would be called Project Apollo, and it had about nine years to meet the President’s deadline. This gave those scientists and engineers less than a decade to do something people had barely started thinking about from a technical perspective. The clock was ticking.
So, You Want to Land on the Moon?
If you want to land on the Moon—and come back to Earth—you’re going to need at least two things: a gigantic rocket, and a spacecraft able to land and come back.
At this point it’s important to note that spaceships in sci-fi movies are very different from spacecraft that were built in the 1960s, or even those built today. In movies, spaceships are usually an all-in-one vehicle, like the Millennium Falcon or the starship Enterprise. Fictional ships like this take off from planets, fly around in space, and land all on their own, all in one piece. In real life, we aren’t quite there yet.
It’s incredibly hard to get off of Earth. Our planet has a lot of gravity that tries to pull you right back down. Long story short, you need a very powerful rocket to leave the Earth’s gravity. But once you’re in space, the rocket has done its job and there’s no further need to lug it around with you. We don’t need the rocket to get back down to Earth either. That’s where gravity is our friend. We can just fall back to Earth, albeit in a controlled manner so as not to burn up in the atmosphere.
So, what we usually do is build small spacecraft called capsules, and put them on top of a powerful rocket. The rocket lifts the capsule into space, where it then separates and goes wherever it needs to. The rocket, meanwhile, falls back down to Earth.
For the Apollo program, NASA put three astronauts in a capsule, put the capsule on top of a rocket, and launched them toward the Moon. This sounds simple enough, but there was one minor detail to attend to: No one had ever built a rocket that was able to do this. No one had ever built a rocket that could lift a spaceship and three people at a fast enough speed that they could escape the gravity of Earth and get to the Moon.
To add to NASA’s problems, no one had ever designed a spacecraft able to land on another world and take off again. Both NASA and Russia had sent robotic missions that landed on the Moon in the late 1960s, but none of these were designed to return to Earth or carry humans.
After exploring all the options for getting to the Moon, landing, and getting home, NASA came to a conclusion: they needed one very big rocket and two different spacecraft.
The plan went like this: The massive rocket would have the two spacecraft placed on top of it. There would be three astronauts onboard, right at the top. The giant rocket would push both spacecraft into space. Once in space, while still near the Earth, the two craft would connect and start flying towards the Moon. The rocket would then fall back down to Earth having completed its job.
Once the two spacecraft got to the Moon a few days later, they would detach from each other. One would remain flying above the Moon (staying in orbit) with one astronaut onboard. The other craft, carrying two astronauts, would land on the Moon’s surface.
The astronauts that made the journey down to the lunar surface would walk around for a bit, collect some rocks, then launch off the Moon back up to the other spacecraft that had remained in orbit. Thankfully, it’s much easier to launch off the Moon than the Earth because there is no atmosphere, as well as much less gravity holding you down. Getting off the Moon only requires a small booster.
After getting off the Moon and reaching the other craft, the two would reconnect and the Moonwalking astronauts would rejoin the third that had stayed in orbit above them. Reunited in the same spacecraft, the three astronauts would make their way back home to Earth. Since they didn’t need two spacecraft to go back home, they would leave one to fall back down to the Moon just before they left.
As our three astronauts returned to Earth, the Command Module would fly through the atmosphere and deploy multiple huge parachutes—each one nearly half the size of an Olympic swimming pool—and land softly on the ocean. They would float there until being picked up by a naval carrier and brought back to shore.
No one said going to the Moon would be easy.
That Big Rocket:
The Saturn V
Next time you’re in a city, find a building that’s about thirty stories high. That’s the height of the rocket built by NASA to send humans to the Moon. The rocket was called the Saturn Five. The “five” is always written in Roman numerals, so it’s written out as “Saturn V.” To this day, over fifty years later, the Saturn V is still the most powerful vehicle ever built by humans.
Like a lot of rockets, the Saturn V was what’s called a multistage rocket. These rockets shed weight as they fly. This is good as lighter things can fly faster and will have an easier time escaping the pull of Earth’s gravity. Multistage rockets are built in sections (“stages”) and burn fuel from the bottom up. When the fuel from one section is used up, that section breaks off and the rocket becomes lighter.
Spacecraft 1: The Command/Service Module
The Command/Service Module was a three-seater capsule that sat right at the top of the Saturn V. When the Saturn V was on the launch pad, the astronauts would be sitting with their backs to the ground looking straight up at the sky. The only thing on top of this craft was a small escape rocket for emergencies. This escape rocket was like an ejection seat for all three astronauts, but it was only needed in case of an accident on the launch pad; it would be discarded right after takeoff if unused and wouldn’t go into space.
The Command/Service Module had two parts: the Command Module and the Service Module, hence the name “Command/Service Module.” The Command Module was a triangular capsule at the front where the astronauts sat and controlled everything. The Service Module was the cargo part of the spacecraft behind them. NASA figured it would take the astronauts about three days to get to the moon. This meant they would need about seven days worth of food, power, and oxygen to cover the day at the moon and the return trip. Essentially, the Service Module was the supply closet for the mission. To simplify things, from here on out, we’ll just call this whole craft the “Command Module.”
NASA also attached a very small rocket engine to the back of the Command Module so that the astronauts could make maneuvers on their way to the Moon. This was critical for entering the Moon’s orbit, which required precise flying to account for the Moon’s own, albeit weaker, gravitational pull. When an Apollo mission was over, the Command Module would return to Earth’s orbit from the Moon and split in two. Only the triangular “command” part with the three astronauts onboard would return safely to Earth’s surface. The supply closet that was the Service Module was left to orbit the Earth and eventually crash into the ocean.
Spacecraft 2: The Lunar Module
At this point we’ve got a big rocket, a place to sit and control the spacecraft, and a place to keep all the important things like food and oxygen. So, what else do we need? Well, a huge part of going to the Moon was flying down to the lunar surface, landing, and being able to come back.
For this part, NASA had some decisions to make. They realized that the Command Module couldn’t perform the actual moon landing once it got there. Instead, the solution was to build an entirely separate spacecraft that came along for the ride and would only be used for going up and down to the lunar surface. This craft would attach to the front
