The code that led Neil Armstrong and Buzz Aldrin to the moon has been released in digital form for public access. Nearly six decades after the Apollo 11 mission, the original flight software is now freely available on GitHub.
The repository, released by NASA's Chris Garry and marked as public, contains two separate programs: Comanche055, used in the Apollo Command Module, and Luminary099, used in the Lunar Module.
Both programs were written for the Apollo Guidance Computer (AGC), a machine whose specifications are now incredible – 3.840 bytes of RAM and 69.120 bytes of storage. The AGC ran about 85.000 instructions per second. These limits defined some of the most efficient software ever written.
The digitization of the code was made possible through a collaboration between Virtual AGC, a preservation project dedicated to the Apollo computer, and the MIT Museum, which holds the original paper entries. Scanned and edited line by line, the files are now accessible online – pages of the assembly language that powered humanity’s first successful journey to the Moon.
Inside Comanche055 are scripts that show how this software handled life-or-death situations with astonishing simplicity. A file, ALARM_AND_ABORT.agc, explains the logic for monitoring and handling critical errors. Comments in the code describe the code's role: logging alarm conditions, turning on the warning light when necessary, and deciding whether an error requires aborting the mission.
Another frequently cited text illustrates the mathematical core of Apollo guidance – about 30 lines of assembly code that calculate navigation trajectories, the computational essence of a mechanics that has no redundant points for the limited memory of the AGC.
Although the press releases will range from very select to rare, I said I'd pass...because sometimes the editors hide.
