How Fiber Artists Got Us to the Moon

Today we celebrate the 50th anniversary of when humans first set foot on the Moon — a moment that forever altered our perceptions of what was scientifically achievable and captured our imaginations for what else we could accomplish. As we look back and remember the thousands of people who made the first lunar landing possible, I would like to turn our attention to a small group of ladies who could have been one of us back in 1969: The Little Old Lady core rope memory weavers.

We already know that the Apollo program was dependent upon thousands of pages of coding, as illustrated in this now famous photo of Margaret Hamilton standing next to the stack of coding she and her MIT team developed for the Apollo Guidance and Navigation System (AGNS).

In order to incorporate the coding into the computer, a fixed memory system was developed that was comprised of ferrite cores woven into a rope with copper wires. As most of us are aware, computer programmers typically use binary code for encoding computer processor instructions and data. Binary code is a two-symbol system that often uses “0” and “1” as the two symbols, but for AGNS, the software was encoded according to the binary pattern of its rope weave. Ah, yes. Now I’m speaking the fiber language.

This weaving was done by hand on specialized looms: a “1” was coded by passing a wire through a magnetic ring while a “0” was coded by passing the wire around it. As anyone who has crocheted a basic lace pattern can imagine, this process was slow and tedious with immense potential for human error. In fact, supervisors discovered first hand how difficult this task was when the weavers went on strike and the supervisors attempted to take over the weaving themselves. After the strike was over, every bit of the weaving that had been done by the supervisors had to be thrown out, and in the end the fiber artists created this masterpiece that guided Apollo 11 to the moon.

And just who were the weavers who worked on this program? Their names have been lost to history, but we know that they were women who were recruited from a textile factory in Waltham, Massachusetts. As such, Apollo programmers nicknamed the finished product “LOL memory” or “Little Old Lady memory.”

To Margaret Hamilton and the Little Old Ladies of the Apollo program: we salute you.