There's more than just space travel in the code that powered the Apollo spaceship

The Takeaway
Astronaut Edgar Mitchell on the moon

“This is the code that brought us to the moon.”

The original source code from Apollo 11 has been posted on the popular programmer website, GitHub. Keith Collins, reporter for Quartz, calls it a 1960s time capsule that “still inspires this awe.”

To begin, it’s awe-inspiring that we went to the moon on so little code — just thousands of lines. Google, an extreme case of simplified coding today, is made up of 2 billion lines of code.

This gap in technology exists because when Apollo 11 was getting ready to launch, code didn’t exist. Collins explains that while developing the Apollo 11 space program, programmers at MIT’s Instrumentation Laboratory were inventing flight software we take for granted today.

Collins says, “They did a lot of work with very little space. One programmer has worked out that an iPhone, which we carry around in our pockets today, has enough code to run 120 million Apollo missions.”

What the MIT researchers came up with was a new way to store computer programs, called “rope memory,” and they created a new assembly programming language. The language is difficult to read and obscure to most modern programmers.

Which is why it takes a tech researcher like Ron Burkey to understand Apollo 11’s assembly code and make it accessible today. Burkey told Collins that, because MIT put the files online in the form of page images, the pages were mutilated. Some were almost unreadable.

After typing up each code line, one by one, from the MIT archive, Burkey filled in the illegible parts with his engineering knowledge. Later, replacement scans would verify his accuracy.

But this new programming system wasn’t just a feat of early computer code. Looking at the code now, it’s a glimpse into the cultural references and current events of the 1960s.

When Collins recounts the read-between-the-code commentary, he can’t help but laugh. “One of my favorites was a sub-routine file called ‘BURN_BABY_BURN’.”

“It traces back to 1965 and the Los Angeles riots, and was inspired by disc jockey and radio station owner Magnificent Montague. Magnificent Montague used the phrase “Burn, baby! BURN!” when spinning the hottest new records.”

Collins keeps laughing. “That routine that’s named ‘BURN_BABY_BURN’ is the master ignition routine.”

There is code that instructs an astronaut to “PLEASE CRANK THE SILLY THING AROUND.” Two lines of code have the comment, “TEMPORARY, I HOPE I HOPE.” One line announces, “OFF TO SEE THE WIZARD.”

The keyboard and display system program is called “PINBALL_GAME_BUTTONS_AND_LIGHTS.s.”

There’s even a quote from Henry VI by Shakespeare: “IT WILL BE PROVEN TO THY FACE THAT THOU HAST MEN ABOUT THEE THAT USUALLY TALK OF A NOUN AND A VERB, AND SUCH ABOMINABLE WORDS AS NO CHRISTIAN EAR CAN ENDURE TO HEAR.”

Reddit user Baygo22 suggests that the quote is likely a reference to the AGC programming language itself, which uses verbs to describe actions to be performed and nouns to specify which data was affected by the action.

And that, Collins says, that’s the beauty of using the internet for crowd-sourcing analysis. “Simply by putting it on this new platform where programmers congregate today, it just exploded online.”

This story was first published as an interview on PRI's The Takeaway, a public radio program that invites you to be part of the American conversation.

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