Margaret Hamilton wasn’t supposed to invent the modern concept of software and land men on the moon. It was 1960, not a time when women were encouraged to seek out high-powered technical work. Hamilton, a 24-year-old with an undergrad degree in mathematics, had gotten a job as a programmer at MIT, and the plan was for her to support her husband through his three-year stint at Harvard Law. After that, it would be her turn—she wanted a graduate degree in math.

But the Apollo space program came along. And Hamilton stayed in the lab to lead an epic feat of engineering that would help change the future of what was humanly—and digitally—possible.