The technology astronauts used to land on the Moon

Categories: Tech News

By: Marios Constantinou / Created: Tuesday February 23, 2021

The technology astronauts used to land on the Moon

The technology behind the moon landing

The moon landing was pretty much the most important feat of the last century. After years into the Space Race, the technological war that marked the Cold War and brought us some nice tech such as the internet and the GPS, the US managed to land the lunar module on the moon and allow two humans to step on it for the first time in our history, Neil Armstrong and Buzz Aldrin, as part of the Apollo 11 mission.

That feat was peak rocket science, and so it was pretty complicated even for today’s standards. That doesn’t mean, though, that all the tech they used aged well. Indeed, we have progressed way beyond it in such a short time, and now even private companies have got their hands on it – something that would seem unthinkable at the time.

Let’s take a look into how things were.


The Apollo program itself was a collection of amazing engineering feats. Being able to exit the atmosphere and follow the exact trajectory to reach the moon, land on it and come back to Earth, all in the 60s, when computers and supercomputers weren’t nearly as powerful as they are today, is simply incredible.

Even more if you consider the such extreme conditions they were subject to: extremely powerful and hot ascension engines (just remember the Challenger incident), the vacuum of space, the velocities they had to get to reach the moon and return from it, and the temperatures and speed they got during reentry.

And, well, let’s just say engineering isn’t a totally exact science: materials and machine parts can have imperfections and sometimes things can just go unpredictably wrong. The technical aspects had a good bit of help from just plain old luck. You may also know: Crime Syndicates


Surprisingly, the average smartphone today has much more processing power than the Apollo Guidance Computer. More surprisingly yet, the CPU used by the Apollo 11 wasn’t even the most powerful one of the time, considering comparable CPUs were used for the Apple II and Commodore PET a few years afterwards, although it was the first one made of silicon integrated circuit. And it had only about 80 kilobytes of memory, most of it read-only.

Of course, as the AGC didn’t have to keep the Facebook app running in the background, it didn’t have too much problem with processing power. 

Moreover, the threat of cosmic rays impacting the Apollo’s navigation programs was very real. Even though the computer’s memory was heavily shielded from them, radiation in space is still much greater than on Earth, so they had to take every possible precaution. Because of that, many parts of the code consisted of redundant subroutines and error-checking processes to ensure things went smoothly.

Still, do not be surprised if you hear about obsolete processors being used in modern military technology: for critical missions, mistakes are unacceptable, so you need to ensure that you know everything about the technology you are using – especially the hardware bugs.


Even though the programming and processing power did their best to make sure everything went smoothly, it wasn’t enough. Nearing the moon, it reached its limits, and could not help them land on the moon properly anymore. So they turned off autopilot, and Neil Armstrong took the helm.

Armstrong is an experienced naval aviator – meaning he flew planes for the US Navy. He fought in the Korean war and flew in and out of an aircraft carrier. Carriers are one of the hardest things to land on, as their runways are much smaller than usual land runways, and you have to land just right to catch the landing cable that will prevent you from rolling straight to the other side of the runway and into the water.

So he had a lot of experience with difficult landings.

And in the end, it was experience and skill that allowed Armstrong to correct the landing trajectory and safely land the lunar module on the lunar soil. Sometimes those are the best technologies that one can have on their side.