R.I.P. Margaret Hamilton, whose code saved the Apollo 11 Moon landing

Margaret Hamilton, the engineer who helped define software engineering itself, has died at 90. Her work wasn’t just early. It sat at the center of NASA’s Apollo effort, where she led the development of the onboard flight software that had to work under brutal pressure and with very little room for error.

Hamilton coined the term “software engineering” and built advanced code at a time when the field was still forming. That alone would make her stand out. But her contribution went further: she led the team using that new technology to build one of the most complex systems humanity had ever achieved, and MIT’s Olivier de Weck called her a fundamental contributor to Apollo’s success.

The praise kept coming late in life. Hamilton received the Presidential Medal of Freedom in 2016, and the next year she showed up as a LEGO minifig in the Women of NASA set, alongside Mae Jemison and Sally Ride. It’s a neat little sign of how far the culture finally caught up with work that mattered much earlier.

She was born in 1936 in Paoli, Indiana, and graduated from Earlham College in 1958 with a mathematics degree and a philosophy minor. She married James Cox Hamilton that same year, with a plan that reflected the era as much as her own ambitions: she would work until he finished law school, then he would support her through a PhD in mathematics.