Beyond the Code: Unpacking the Hilarious and Human Comments in the Apollo 11 Source Code

The Hidden Humanity Behind the Moon Mission

The Apollo 11 mission stands as one of humanity’s greatest technological achievements. The iconic images of the lunar landing and those famous first steps have been etched into our collective memory for generations. Yet beyond these dramatic moments lies a hidden treasure: the surprisingly witty, human, and often hilarious comments embedded within the mission’s source code.

These annotations provide a fascinating window into the personalities, culture, and humor of the brilliant minds who programmed humanity’s journey to the Moon. Far from dry technical notes, these comments range from the practical to the philosophical, the serious to the surprisingly hilarious, offering a unique glimpse into the minds of individuals who helped land humanity on the moon.

For anyone who has ever dabbled in programming, the necessity of comments is clear. They explain complex logic, clarify intentions, and serve as breadcrumbs for other developers. But the comments in the Apollo 11 source code go above and beyond mere technical annotation. They reveal a team working under immense pressure, yet retaining their wit, creativity, and a profound sense of the historical significance of their task.

The Rediscovery of Apollo’s Digital DNA

The Apollo 11 source code remained relatively unknown to the public for decades until 2003, when tech researcher Ron Burkey painstakingly transcribed every line of code by hand from original transcripts. But it wasn’t until July 2016 that the code truly captured public imagination, when former NASA intern Chris Garry uploaded the entire software onto GitHub, making it accessible to programmers worldwide.

When Chris Garry uploaded the Apollo 11 code to GitHub in 2016, it quickly became a hub of activity and interest. Programmers and space enthusiasts alike began examining the code, leaving comments, and even submitting humorous “pull requests” suggesting improvements. One joking suggestion was to add a file called “MATTDAMON.s” so “we can save that poor man from Mars,” a reference to the film “The Martian.”

This continuing fascination speaks to our desire to find human connection in technological achievements. The comments humanize what might otherwise seem like an impenetrable technical accomplishment, reminding us that even the most sophisticated technology is created by people with personalities, humor, and cultural reference points.

The Unlikely Cradle of Space Software: The AGC and Its Constraints

To truly appreciate these comments, we first need to understand the environment in which the Apollo 11 software was born. The Apollo Guidance Computer (AGC) was a marvel of its time, a compact digital computer (weighing about 70 pounds) designed to operate in the harsh environment of space. However, by today’s standards, its capabilities were incredibly limited.

The AGC operated with just 36 kilobytes of memory and a processing speed of 1 MHz. For perspective, the original Nintendo Game Boy released 20 years later in 1989 was four times faster and had twice the memory. A modern iPhone is approximately 1,800 times faster with 500,000 times more memory than the computer that guided humans to the Moon.

NASA and MIT engineers had to create their own version of assembly language, a low-level programming language that was closer to machine code than human language. This made the programming task even more challenging, as reflected in the famous photograph of Margaret Hamilton standing next to a stack of code printouts taller than herself.

Table: Comparing Apollo Guidance Computer to Other Technologies

Device	Processing Speed	Memory	Release Date	Comparison to AGC
Apollo Guidance Computer	1 MHz	36 KB	1969	Baseline
Nintendo Game Boy	4 MHz	64 KB	1989	4x faster, 2x memory
Modern iPhone	~1,800 MHz	~18,000,000 KB	2020s	1,800x faster, 500,000x memory

This unforgiving environment demanded code that was not only functionally perfect but also meticulously planned and documented. The programming language itself was a low-level assembly language specific to the AGC. Unlike modern languages that use human-readable commands, Assembly requires programmers to think much closer to the machine’s architecture, manipulating individual bits and bytes.

The Software Team: Pioneers Under Pressure

The software that guided Apollo 11 was developed by programmers at MIT’s Instrumentation Laboratory in the 1960s, led by legendary software engineer Margaret Hamilton. These pioneers not only accomplished the near-impossible task of landing humans on the moon but did so while maintaining their sense of humor and humanity in the face of enormous pressure.

Margaret Hamilton led the team that created the onboard Apollo software, bringing a level of rigor and precision that set new standards in the emerging field of software engineering. Her approach was so effective that “no software bugs were ever known to have occurred during any crewed Apollo missions” – an astounding achievement that remains remarkable even by today’s standards.

The programmers on Hamilton’s team were relatively young, many in their twenties. They were pioneers in a nascent field, developing best practices as they went along. This unique blend of intense pressure, groundbreaking work, limited resources, and a youthful, intelligent team created a fertile ground for a unique coding culture – one that is vividly reflected in the comments they left behind.

The Greatest Hits: Iconic Comments That Reveal the Human Touch

Scrolling through the Apollo 11 source code is an eye-opening experience. While the Assembly code itself can be daunting, the comments offer moments of levity, insight, and even poetry.

BURN_BABY_BURN: The Most Famous Code Comment

Perhaps no comment in the Apollo 11 code has garnered more attention than the title of the master ignition routine: “BURN_BABY_BURNMASTER_IGNITION_ROUTINE”. This wasn’t just a random joke – it was a reference to a popular phrase and hit song from the 1960s. The routine was absolutely mission-critical; it controlled the precise firing of the lunar module’s rocket engine to establish orbit around the moon.

The importance of this particular code section cannot be overstated. As one source explains: “Getting this burn right was crucial to the mission – get the angle wrong and either the lunar module would crash into moon’s surface, or would never get captured by moon’s feeble gravity and would drift away into deep space, to be lost forever”. The programmers even included an explanation for the name, noting it was inspired by disc jockey Magnificent Montague’s popular phrase “Burn, baby! BURN!” which he used when playing the hottest records.

To find this piece of contemporary popular culture embedded in the mission-critical code for igniting the engines of a spacecraft heading to the moon is nothing short of astonishing. It speaks to the programmers’ connection to the world outside their intense work environment and their willingness to inject personality even into the most serious sections of the code.

Shakespeare in Space: Literary References in the Code

The Apollo 11 programmers weren’t just technical experts, they were well-read individuals who brought their literary knowledge to their work. One of the most unexpected discoveries in the code was a Shakespeare quotation from “Henry VI” in the file PINBALL_GAME_BUTTONS_AND_LIGHTS.s. This file, which handles the keyboard and display system, opens with:

“It will be proved 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”.

This clever reference ties perfectly to the verb/noun user interface used by the Apollo Guidance Computer, demonstrating both the wit and erudition of the programming team. This appears in a comment block and is almost certainly a witty jab at the AGC’s user interface. Astronauts interacted with the computer by inputting two-digit codes, one designated as a “Verb” (the action to be performed) and the other as a “Noun” (the data to be acted upon).

The quote humorously implies that speaking in terms of “nouns” and “verbs” is strange and perhaps unbearable to listen to. This demonstrates the programmers’ intellectual wit and their self-awareness regarding the sometimes clunky nature of the interface they had to design, given the technological constraints.

PINBALL_GAME_BUTTONS_AND_LIGHTS and Other Playful Names

The Apollo programmers showed their creativity in the very naming of their files and routines. “PINBALL_GAME_BUTTONS_AND_LIGHTS.s” is among the most memorable, representing the keyboard and display system interface for the Apollo Guidance Computer AGC.

Interestingly, this user interface has a remarkable origin story. According to historical accounts, “nobody had yet arrived at any kind of software requirements for the AGC’s user interface when the desire arose within the Instrumentation Laboratory to set up a demo guidance-computer unit with which to impress visitors to the lab”. The programmers quickly threw together the verb/noun interface concept for this demo, never expecting it would become part of the actual flight software. As people became familiar with the demo, no one developed a better alternative, so it was incorporated into the mission code.

The DSKY (Display/Keyboard unit), with its array of lights and buttons, might well have resembled a pinball machine to the programmers. This playful naming convention highlights the informal atmosphere within the team and their ability to find lightheartedness in the tools of their trade.

“Trashy Little Subroutines” and Other Candid Comments

The programmers weren’t afraid to be candid or self-deprecating in their annotations. In the LUNAR_LANDING_GUIDANCE_EQUATIONS.s file, a section is bluntly labeled “Trashy Little Subroutines”. Another command in the same section is mysteriously dubbed “Numero Mysterioso”. These comments reveal a refreshing honesty and informality that contrasts with the mission’s high stakes.

Another wonderfully relatable comment found in the code is: “TEMPORARY, I HOPE I HOPE”. Found in a section of code that likely represented a temporary fix or workaround implemented under pressure, this comment perfectly captures the anxiety and hope associated with such solutions in any software development project, then or now. It’s a poignant reminder that even the most brilliant engineers on a historic mission faced the same practical realities and uncertainties that programmers encounter daily.

The comment “GO TO POOH” is another intriguing example. It’s associated with code that handled program alarms, specifically those that occurred during the critical lunar landing sequence (the famous 1201 and 1202 alarms). The most common interpretation is that “POOH” is a reference to Winnie the Pooh, perhaps suggesting the program was heading into a confusing or “sticky” situation.

Finally, the comment “PLEASE CRANK THE SILLY THING AROUND” offers a glimpse into the direct and sometimes informal communication style embedded in the code. This appears near instructions for the astronaut to manually reposition the lunar module’s landing radar antenna. “The silly thing” refers to the antenna itself. This comment reads like a direct instruction or a helpful note from a programmer to the astronaut, a surprisingly casual phrase within the critical descent code.

Beyond the Jokes: Comments as a Window into Programming Past

While the humorous comments are the most famous, the vast majority of annotations in the Apollo 11 source code are purely technical. However, even these technical comments offer valuable insights into the programming practices of the era:

Table: The Functions of Comments in Apollo 11 Code

Function	Purpose	Example/Context
Technical Documentation	Explain complex logic and algorithms	Detailed explanations of mathematical calculations
Knowledge Transfer	Ensure team members understand the code	Comments explaining variable purposes and functions
Support for Core Rope Weaving	Guide the physical implementation	Notes for the women who wove core rope memory
Contextual Information	Provide mission-specific details	Comments about physical systems being controlled
Personal Expression	Add humanity to technical work	Humorous asides and cultural references

Extensive Documentation

The sheer volume of comments highlights the critical importance placed on documentation. In the absence of sophisticated debugging tools and with the immutable nature of core rope memory, programmers had to be meticulous in explaining their logic and the purpose of each section of code. Every decision, every variable, every routine was carefully annotated.

Support for the Weaving Process

The comments were also vital for the women who physically wove the core rope memory. Core rope memory was literally hand-woven by skilled workers, often women, threading wires through or around tiny magnetic cores to represent binary ones and zeros. They needed to understand the structure and intent of the code to accurately translate the digital instructions into physical connections. The comments served as a form of communication between the programmers and the memory weavers.

A Form of Version Control and Knowledge Transfer

In an era before modern version control systems were commonplace, the detailed comments served as a crucial record of the code’s development and logic. They were a way to transfer knowledge within the team and ensure that everyone understood how the complex system worked.

Why Include Humor in Mission-Critical Code?

The presence of jokes in software so critical to human safety raises an interesting question: why would programmers include such elements in the first place? Several factors likely contributed to this practice.

First, humor often serves as a coping mechanism in high-pressure environments. The Apollo program represented the pinnacle of technological ambition in the 1960s, with immense national prestige and human lives at stake. Injecting humor into their work likely helped alleviate this stress.

Second, these comments fostered team bonding and morale. Programming in the 1960s was a collaborative effort that required countless hours of focused work. Sharing inside jokes and references would have created a sense of camaraderie among the coding team.

Finally, the comments reflect the cultural context of the 1960s. References to popular music, Shakespeare, and contemporary slang demonstrate that these weren’t just technical specialists – they were people embedded in the cultural moment of their time, bringing their whole selves to this historic project.

Legacy for Modern Programmers

The Apollo 11 code comments offer valuable lessons for today’s software developers. They demonstrate that even in the most mission-critical applications, there’s room for humanity and personality. They show how comments can provide not just technical clarification but context, motivation, and even moments of levity that make code more accessible to other humans.

At the same time, they remind us of how far computing has advanced. Modern programmers work with tools, languages, and computing power that would have seemed magical to the Apollo team. Yet many of the fundamental challenges remain the same: clear communication, rigorous testing, and translating human intentions into machine instructions.

Comparing the commenting style in the Apollo 11 code to modern practices reveals how far software development has come. While good comments are still valued today, the level of detailed explanation found in the Apollo code is often less necessary due to higher-level programming languages, powerful integrated development environments (IDEs) with debugging tools, and sophisticated version control systems that track every change.

If you’re interested in learning more about the Apollo Guidance Computer’s remarkable capabilities, check out our detailed explanation of how a 32KB computer and 3 critical seconds saved the moon landing.

Conclusion: The Human Side of the Moon Landing

The humorous and personal comments in the Apollo 11 source code transform our understanding of one of humanity’s greatest achievements. They reveal that behind every line of code that guided astronauts to the Moon were real people with personalities, senses of humor, and cultural references that mattered to them.

These annotations remind us that the greatest technological accomplishments are, at their core, human endeavors. They show that even when working on history-defining projects with the highest stakes, people bring their full humanity to the task, including their wit, literary knowledge, and cultural touchstones.

As we continue to push the boundaries of space exploration and technology, the Apollo 11 code stands as a testament to the power of human creativity, humor, and determination. In those carefully crafted comments, we find not just technical instructions but the spirit that carried humanity to the Moon and back – a spirit that continues to inspire programmers, engineers, and dreamers more than half a century later.

For space enthusiasts looking to explore the cosmos themselves, check out our guide to finding the best telescopes for amateur astronomers. And if you’re fascinated by the technical challenges faced by the Apollo team, you might enjoy learning about the challenges of IMU gimbal lock in Apollo navigation systems.

For deeper dives into Apollo’s software engineering achievements, explore our articles on the Apollo guidance software engineering and the saved documentation of the Apollo Guidance Computer.

Want to learn more about the people who managed these historic missions? Read our profile on the Maestros of the MOCR: Meet the Apollo Flight Directors.

For more fascinating space history content, be sure to check out our YouTube channel, where we regularly post videos exploring the technical and human stories behind humanity’s greatest adventure.

Best Telescopes 2025