How Weaving Took Us to the Moon

Learn about core rope memory and how it's a part of both weaving history and scientific history. Without weavers, we couldn't have gotten to the moon!

Handwoven Editors Jul 19, 2016 - 4 min read

How Weaving Took Us to the Moon Primary Image

BeWeave It

Many of us who are more artistic or literarily-inclined than we are mathematical or scientific sometimes get down on ourselves. If you ever feel this way, remind yourself that weaving history got us to the moon.

“Wait,” you might be thinking, “back up here. To the moon?”

Yes. To the moon. Specifically, little old ladies weaving got us to the moon.

The Apollo missions were equipped with the smallest, most sophisticated guidance computers available at the time, but there was a problem with the software needed to run them, especially when the ship would be on the other side of the moon from Earth.

The programs were initially written the same way most computer programs in those days were coded: magnetic tapes read by disc drives that were far too large to send into space. Code could also be written on paper punch cards that had to be read by machines, again far too large to go into space. Both options were also too delicate to take the punishment of launch, temperature changes, and cosmic radiation that they’d experience throughout the voyage. Whatever solution they came to would even need to be able to survive power losses without losing the program!

The solution available was a technology called core rope memory, an example of which you can see at right. Like other programming languages, core rope memory had a specific method of coding ones and zeros, which a computer could then read. Rather than coding these ones and zeros with punches, as in the card system, the binary language was coded with magnets and wires.

Core rope memory was actually woven by hand on an unusual kind of loom that allowed one to thread individual wires through specific holes. To code a one, a wire was threaded through a magnetic ring. If a ring was skipped, it was a zero. These magnetic rings changed the voltage of the current running through the wire. So if the reader detected a current change, it knew that was a one. No voltage change meant a zero. It’s not unlike floats in weaving. In fact, weaving is itself a binary language of shafts raised and lowered! Weaving drafts are a way of “programming” your weaving.

The entire program was woven by hand this way into a format that resembled rope, but was really woven electrical pathways. Very complex ones, at that! Not just anyone could manufacture it, due to the tremendous complexity and high stakes in the case of a mistake. Once a core rope was finished, the only way to make a change was to unweave the whole thing and start again. And any mistakes that went into space could risk the lives of astronauts.

Highly-specialized garment workers, often older women, were trained to weave core rope memory because they had the attention to detail necessary to get it right the first time. For this reason core rope memory was often not-so-nicely referred to as LOL memory, standing for “Little Old Lady” memory. It's a little-known but very important part of weaving history!

So here’s to us “little old ladies,” whether we just fit that label in terms of our fiber-ly habits or if we truly are getting on in years. Our skills and specialties are valuable enough that without them, all those smart engineers couldn’t have gotten to the moon!