Register for class: https://howardcounty.librarycalendar.com/events/weaving-our-way-moon 
Saturday, March 19; 3 – 4 pm
HCLS Glenwood Branch
Ages 11 and up. Allow 20 minutes. 

by Lori C.

Learn the fascinating forgotten history of the LOLs – the Little Old Ladies of NASA’s Apollo Missions – with a hands-on STEM activity that celebrates the women who “wove our way to the moon.” Discover how core rope memory powered spaceflight, then create a simple beaded message using binary code. 

When you hear the word, “weaving” and the phrase, “little old ladies,” what image comes to mind? Most likely the mental picture is not one of making a sophisticated computer program designed to send the Apollo spacecraft to the moon! For Women’s History Month, we are going to celebrate the women who, using ferrite core beads and copper wire, literally wove the components that made up software programs for the Apollo Guidance Computer.  

The “little old ladies” or LOLs moniker certainly was not the most progressive way of referring to these highly skilled factory workers who crafted the core rope memory for NASA. Their precise weaving and manufacturing skills were crucial to the success of the Apollo program and to the astronauts arriving safely on the Moon.  

The NASA Apollo Guidance Computer used read-only, core rope memory to store its programs. The weaving was complicated: “The cores are arranged in ropes of 1024 cores each. 10 inhibit pairs (20 wires) provide the address-decoder weave as 2^10=1024. Although the memory words are 16 bits wide, each core has up to 64 sense wires woven through it.”* Remarkably, this guidance system used only 72k of memory, which is equivalent to the memory of a simple calculator. 

Want to try your hand at making a simple version of core rope memory in the tradition of the LOLs? Join us at the Glenwood Branch for a brief history overview of the contributions of these amazing women who “wove our way to the moon” and then craft a single word-weaving project using binary code, thread, and beads.   

Lori, the Teens’ Instructor & Research Specialist at the Glenwood Branch, idolizes Sally Ride and in an alternate life would have trained to be an astronaut. She also loves baseball, knitting, and reading dystopian novels. 

*Core Rope & Woven-Wire Memory Systems by B. Hilpert, April 2015
https://web.archive.org/web/20160822041959/http://www.cs.ubc.ca/~hilpert/e/corerope/index.html