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.