Margaret Hamilton, a Pioneering Software Engineer Who Made the First Human Moon Landing Possible, Dies at 90

Hamilton popularized the term “software engineer” and created computer programs that could anticipate problems. She received a Presidential Medal of Freedom and was inducted into the National Aviation Hall of Fame

October 8, 2026 2:42 p.m.

a black and while image of Hamilton reaching for a panel covered in switches — Margaret Hamilton in the Apollo Command Module NASA

Software engineering pioneer Margaret Hamilton died on September 30 at age 90, leaving behind a trailblazing legacy of problem-solving and entrepreneurship that paved the way for a new branch of computer science and engineering.

Hamilton is best known for her major contributions to the Apollo missions. Her work famously resolved a computer issue that enabled NASA’s Apollo 11 mission to put humans on the moon for the first time.

“Her coding foresight and prowess really made that mission a success,” Andrew Meade McGee, curator of computing at Smithsonian’s National Air and Space Museum, tells Smithsonian magazine. Her impact goes far beyond the lunar landing, though, and has had long-lasting effects, he adds. “She created the logical software basis for many of the critical systems we use to maintain our infrastructure today, and that silently power today’s modern aerospace world.”

Hamilton was not widely recognized outside of computing and aerospace circles until about 20 years ago, and in 2016, she received the Presidential Medal of Freedom, McGee says. “A generation of coders and young women in STEM came to see her as a pioneer.”

Hamilton was born in Paoli, Indiana, in 1936. After earning her bachelor’s degree in mathematics from Earlham College in 1958, she and her husband moved to Massachusetts. Hamilton started working on weather prediction software at MIT with Edward N. Lorenz, the meteorologist who founded chaos theory. This position marked the beginning of her computer programming journey.

A black-and-white image of a long-haired women next to a giant pile of paper almost as tall as she is — Margaret Hamilton and a stack of Apollo project navigation software Draper Laboratory / Restored by Wilfredor and Yann

In 1965, she joined the Instrumentation Lab at MIT, which was tasked with developing the onboard flight software for the Apollo program, with the goal of sending humans to the moon.

“I was attracted both by the sheer idea and the fact that it had never been done before. I was the first programmer to join and the first woman they hired,” Hamilton told the Guardian’s Zoë Corbyn in 2019. “Male engineers were already working on the project, but they were hardware engineers, and it wasn’t their thing. I had [software writing] as my background. I think [the lab] just figured that I could handle the unknown.”

Hamilton eventually became the lead of the team creating the on-board flight software for the crewed missions and then assistant director in charge of the Command and Service Module team.

Quick fact: What was the first spacecraft on the moon?

The uncrewed Soviet spacecraft Luna 2 was the first human-made object to reach our celestial companion when it crash-landed there in 1959.

Her signature work in the field was “defensive” programming—computer programs capable of predicting or fixing issues by themselves—and “priority-driven” software. The approach played a major role in the first human moon landing in July 1969. Shortly before the landing module was supposed to reach the lunar surface, alarms sounded from the onboard computer. A fault in a hardware switch had caused the computer to overload, threatening the success of the mission.

Thankfully, Hamilton and her colleagues’ priority-driven software turned off unnecessary background tasks to make room for top-priority tasks, and the mission was able to carry on. “I was not concentrating on the mission per se, I was concentrating on the software,” she explained in an interview with Makers in 2017. “All of a sudden, it was like everything you did on Apollo to that point in time, it just all happened in front of you. People say that before they’re no longer here, they see their life. I could see the Apollo life. Just, my god, look what happened. We did it. It worked.”

Landing on the Moon - Margaret Hamilton MAKERS Moment

No issues were ever found in any of the Apollo guidance software overseen by Hamilton, according to the Wall Street Journal’s Robert Lee Hotz. What’s more, Hamilton popularized the term software engineering.

“I fought to bring the software legitimacy so that it—and those building it—would be given its due respect, and thus I began to use the term ‘software engineering’ to distinguish it from hardware and other kinds of engineering, yet treat each type of engineering as part of the overall systems engineering process,” Hamilton told El Pais’ Javier Pedreira in 2017, per a translation cited by MIT. “When I first started using this phrase, it was considered to be quite amusing.”

In 1976, Hamilton founded the software company Higher Order Software. A decade later, she founded her second software company, Hamilton Technologies. She is an author of more than 130 publications, according to MIT.

In 2003, she was honored with a NASA Exceptional Space Act Award for her scientific and technical contributions. Hamilton also won the Computer History Museum Fellow Award in 2017 and the Intrepid Lifetime Achievement Award in 2019, and she was inducted into the National Aviation Hall of Fame in 2022. The Smithsonian’s National Air and Space Museum awarded her the 2025 Michael Collins Trophy for lifetime achievement.

Hamilton was even immortalized in Lego’s now-retired Women of NASA set. She is survived by three siblings, her daughter, son-in-law, two grandsons and four great-grandchildren.

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