We’ve all had jobs that asked a lot of us. Sometimes the work that needs to get done requires more hours than it seems like any sane person would give, leaving you and your coworkers with no choice but to find ways to make another few hours bearable, another long night survivable, and another humorless situation just a bit funnier. Many of us who have served can recall long, sleepless nights that forced us to find humor in serious, or even life-threatening, situations—and thanks to the recent release of Apollo 11’s source code, we now know that the men and women at NASA are no exception.

Apollo 11 was an audacious enterprise. We humans chose to go to the moon “not because it’s easy, but because it is hard,” and that objective left many programmers typing away into the night, anxiously creating software that could guide a metal box farther away from the surface of the Earth than men had ever dared venture, land safely on a rock circling our planet at 2,288 miles per hour, then take off again and bring those men back safely to Earth using computers substantially less powerful than the smartphone you have in your pocket.

I’d imagine those programmers worked some late nights, and just like each of us when we find ourselves working late, they tried to find humor in their work. Unlike many of us, however, they chose to actually code some of that humor into the final product, leaving jokes and pop culture references littered throughout the very coding that guided Apollo’s rockets.

The Apollo Guidance Computer (AGC) on board the command module and lunar lander used in Apollo 11 was so advanced at the time that the MIT Instrumentation Laboratory had to develop a new kind of software to support it. Scanned images of the code written have been available to the public for years, but in 2003, an unnamed but devoted person chose to transcribe the images of the coding into searchable text. Then, in July of this year, a former NASA intern named Chris Garry uploaded the transcribed coding onto GitHub, where other programming aficionados began excitedly analyzing the historic lines of code that got Neil Armstrong and Buzz Aldrin to the moon. What they found was quite surprising.