Role Model Sunday: Margaret Hamilton

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Portrait of Margaret Hamilton, 1995This woman’s story could be found in my (and probably your) facebook stream for a couple of months, on and off. The picture I’m posting here is way more recent than the famous one used in all the postings telling us about her greatest achievement, so you probably didn’t recognize here. The famous picture is that of a young woman, wearing big glasses and a striped dress, proudly smiling into the camera, standing next to a huge pile of documents.

Meet Margaret Hamilton, the woman who sent the Apollo mission to the moon (and back again).

Margaret Hamilton had a B.A. in mathematics from Earlham College, and after teaching highschool mathematics for some time, she and her husband moved to Boston. The plan was for him to finish his graduate studies, while Margaret would be working to sustain them both, in order to finish a graduate programme in mathematics when he was done with his.

Hamilton popularized the term “software engineering” (coinedby Anthony Oettinger), and was one of those who developed important software concepts. Some of these are priority scheduling, end-to-end testing, and human-in-the-loop decision capability, such as priority displays.

As a working mother in the 1960s, Hamilton was unusual. She would bring her daughter Lauren to the lab on weekends and evenings. While the 4-year-old slept on the floor of the office, her mother programmed away. She loved the novelty of her job (“like the Wild West” is a term she used in an interview), and also liked the camaraderie. There were after-work drinks at the MIT faculty club, geek jokes and the like. At the lab, she said, she was “one of the guys.”

In 1965, Hamilton became responsible for the onboard flight software on the Apollo computers. Sometimes the pressure kept Hamilton up at night. Once, after a party, she rushed back to the lab to correct some code she’d suddenly realized was flawed. “I was always imagining headlines in the newspapers, and they would point back to how it happened, and it would point back to me.” (WIRED)

One day, when Hamilton’s daughter Lauren was playing with the MIT command module simulator’s display-and-keyboard unit. As she toyed with the keyboard, an error message popped up. Lauren had crashed the Apollo simulator by somehow launching a prelaunch program called P01 while the simulator was in midflight. There was no reason an astronaut would ever do this, but nonetheless, Hamilton wanted to add code to prevent the crash. That idea was overruled by NASA.  They told Hamilton and her team over and over that astronauts were trained to be perfect, so they would never make that mistake. She wanted to add error-checking code to the Apollo system that would prevent this from messing up the systems. But that seemed excessive to her higher-ups. “Everyone said, ‘That would never happen,’” Hamilton remembers.

But it did happen. Five days into the historic Apollo 8 flight which brought astronauts to the moon for the first-ever manned orbit, the astronaut Jim Lovell inadvertently selected P01 during flight. This wiped out all the navigation data Lovell had been collecting. Without that data, the computer wouldn’t be able to calculate and execute the route back. But Hamilton and her team developed a plan based on her program note regarding the problem, and thanks to that —and Lauren—the Apollo astronauts came home.

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