Margaret Hamilton, Apollo Computer Programmer, has Died

The Woman Whose Software Guided the Apollo Missions Has Died

Margaret Hamilton, the first female programmer hired to work on the space project at M.I.T., was 90.

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https://www.nytimes.com/2026/10/07/obituaries/margaret-hamilton-dead.html?unlocked_article_code=1.HFE.LyzK.61NCdD3ArbP7&smid=url-share

By Trip Gabriel  NYT

Published Oct. 7, 2026Updated Oct. 8, 2026, 9:09 a.m. ET

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Margaret Hamilton, who led the 100-person team that wrote the onboard software for the Apollo missions, guiding Neil Armstrong and Buzz Aldrin to a safe landing on the moon, died on Sept. 30 in Cambridge, Mass. She was 90.

Her death, in a hospital, was confirmed by her daughter, Lauren.

Ms. Hamilton was a young mathematician at the Massachusetts Institute of Technology in the early 1960s, putting her husband through law school by working in a computer lab. When she learned that M.I.T. was designing in-flight computers for the moon mission, she eagerly joined the team.She was the first female programmer hired to work on the Apollo project, housed at M.I.T.’s Instrumentation Laboratory, in 1965. Her skills led to her promotion to director of software engineering on the project, which developed the two 70-pound onboard computers for the Apollo flights: one in the command module, which carried the astronauts from Earth, and the second in the lunar module, which set down on the moon’s surface.

Ms. Hamilton, who would bring her young daughter to work on weekends and evenings, is credited with popularizing the term “software engineering” to describe the complexity of the work her team did, thus elevating software coding to a status equal to hardware design.

A 1969 photograph of the 5-foot-4 Ms. Hamilton standing beside a head-high stack of printed code developed for the moon landing has been widely shared on social media in recent years.

Primary navigation for the Apollo flights was guided from Houston on mainframe IBM computers. But the onboard Apollo Guidance Computer that the M.I.T. lab created was a crucial cog.

Developing its software was a major lift in an era when computers had limited memory. The onboard computers contained only 72 kilobytes of storage memory (an iPhone 16, by comparison, can have more than seven million times as much storage).

As Apollo 11’s lunar module, Eagle, touched down on the moon on July 20, 1969, Ms. Hamilton, then 32, was patched into Mission Control in Houston from M.I.T.

Ms. Hamilton directed the software engineering for the onboard computer of the Apollo 11’s lunar module, seen here, with the astronaut Buzz Aldrin Jr. stepping onto the moon’s surface. Credit...Neil Armstrong/NASA, via Associated Press

“I was not concentrating on the mission per se, I was concentrating on the software,” she recalled in a 2017 interview for the Computer History Museum. She compared the moment before touchdown to the instant before death when a person’s life is said to flash before them. “I could see the Apollo life, just: ‘Look what happened. We did it. It worked,’” she recalled. “It was exciting.”

But it almost didn’t happen. As Eagle neared the moon, its onboard computer famously flashed alarms, and Mission Control was faced with a decision about whether to abort the landing.

One of the astronauts, according to some historians, flipped a switch that overloaded the computer’s processing unit, which set off the alarms. Ms. Hamilton had foreseen just such an event. Her software told the onboard computer to prioritize essential tasks and cancel less important ones. The alarm was the signal that the procedure had occurred. Houston chose to continue the mission, and Eagle’s computer guided it to a safe landing on the Sea of Tranquillity.

“If the computer hadn’t recognized this problem and taken recovery action, I doubt if Apollo 11 would have been the successful moon landing it was,” Ms. Hamilton wrote in a 1971 letter to a computer magazine, Datamation.

Ms. Hamilton worked on the six lunar landing missions from 1969 to 1972. Her programming also contributed to Skylab, America’s first space station, launched in 1973, and to the early design of the space shuttle. She left M.I.T. to found a company, Higher Order Software, in 1976, as well as a second firm a decade later, Hamilton Technologies.

In 2016, President Barack Obama awarded Ms. Hamilton the Presidential Medal of Freedom. Its citation reads that her work for NASA “set the foundation for modern, ultrareliable software design and engineering.”

In 2019, on the 50th anniversary of the moon landing, Google trained more than 100,000 mirrors at its Ivanpah solar power farm in the Mojave Desert to create a nighttime portrait in reflected moonlight of Ms. Hamilton, bigger than Central Park.

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Margaret Hamilton is mentioned frequently in the book "Sumburst and Luminary" by Don Eyles.  

See: https://soldersmoke.blogspot.com/search?q=Eyles

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