We all grew up hearing that the moon landing was one large step for mankind, but few people know about the woman who helped make that first step possible. Margaret Hamilton was a pioneer in the field of software engineering (a term she coined herself), and a leader of the MIT Instrumentation Laboratory which worked with NASA to build Apollo 11’s on-board flight software.

Knowing that it would be impossible to test software on the moon, Hamilton put the software through rigorous simulations on the ground. She and her team identified that the main problem the systems faced were interface errors (like conflicts in timing), and worked to build preventative ways to keep the software functioning smoothly. She would later refer to this kind of preventative measure as Universal Systems Language.

Her contributions were crucial; shortly before the moon landing was supposed to take place (46 years ago this week), alarms were triggered because the computer was being overloaded with incoming data. Fortunately, due to the work done by Hamilton and her team, the computer was able to keep functioning and prioritize which processes (like landing) it should keep running. Later, the team learned that the information overload had merely been caused by a radar switch being placed in the wrong position. The computer’s ability to correct for the error and maintain necessary functions gave NASA the confidence to continue the moon landing, and the rest of the mission is history.

For her work on Apollo 11 systems, Hamilton was given NASA’s Exceptional Space Award Act. She went on to found Hamilton Technologies, where she continued to work and build upon the Universal Systems Language she had done at NASA.

Hamilton worked in a time before the full force of the women’s rights movement, though in an interview this week with Time she said she, “didn’t notice the gender problems of the time until Mad Men came around and seemed a little too familiar.” But she wasn’t oblivious. When the MIT credit union said that a woman on Hamilton’s team had to have her husband’s signature in order to get a loan (though men were not asked to obtain spousal approval), Hamilton had the policy changed. “It was the culture,” she noted, “but I won, and I was so happy.” And, in the true spirit of feminist equality, went on to say, “I didn’t do it because of male versus female; I was very conscious of what was fair and what wasn’t fair.”

A leader in her field and a key player in the race to the moon, Hamilton’s accomplishments prove that there’s a reason why #girlswhocode should be encouraged and celebrated.

(Image via Wikipedia)