Apollo at 50

It’s been 50 years since Apollo 11 launched, and its impact on my life has been profound. The Apollo mission was the most audacious engineering project since the Tower of Babel, and it inspired me in many ways.

The Apollo program is a powerful lesson about bringing together political will, the corresponding budget, and a lot of math and engineering. While the engineering was state-of-the-art for 1969 it is still so amazing that I meet people who think the challenge was so formidable that it was impossible, and was actually just a film set directed by Stanley Kubrick.

The history of designing the Apollo spacecraft is amazing in itself, and there is a beauty in the flow of necessity. The key decision was made to send 3 astronauts, to have 1 in orbit around the moon while the other two descended in the Lunar Module to land on the moon, then to launch and rejoin the orbiting command module. Once you know the mass of the astronauts, their living supplies, the weight of the spacecraft and fuel, the size of the Saturn V was “just math,” calculations that lead to the required velocity and power needed, creating the largest machine every built.

As a software engineer I have a great appreciation for the complexity of building a real-time computer in the 1960s when computers were the size of rooms, and the invention of the transistor was less then twenty years old.

Margaret Hamilton is one of my new-found computer engineering idols, who not only coined the phrase “software engineering” but also showed us by example the difference between computing science and software engineering. Science uses hypothesis and experiment and failure teaches as much or more than success. Engineering is about building things that don’t kill people even when something goes wrong.

Even though the Apollo Guidance Computer was state-of-the-art at the time, it had quite limited capability, something more like a scientific calculator that took input from sensors and a crude user interface called the DSKY. Margaret realized that it was possible for the computer to become overloaded if the sensors send data more often than they should have (an event that actually happened by mistake) and that by creating a computer task whose job it was to self-monitor, could decide to drop low-priority tasks in favour of the critical ones, which included monitoring the landing radar and calculating distance and velocities.

I may have only been 11 years old when the Eagle landed and became Tranquility base, but seeing that people could use science and technology to make a dream come true has been an inspiration for me ever since.

We might feel the same when people set foot on Mars.

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