Margaret Hamilton, Who Led Apollo Software Team, Dies at 90

Margaret Hamilton, the computer scientist who led the team that wrote the onboard flight software for NASA’s Apollo missions, died on 30 September 2026 in Cambridge, Massachusetts. She was 90. Her daughter, Lauren, confirmed the death. MIT announced the news on 7 October. Hamilton was the first woman hired as a programmer on the Apollo project at MIT’s Instrumentation Laboratory in 1965. She rose to direct the software engineering division that produced the code for the two 70-pound guidance computers—one in the command module and one in the lunar module.

Hamilton joined MIT in 1959 while putting her husband through law school. She worked on weather prediction software before moving to the Apollo contract. The laboratory had won the NASA award in 1961. She described being drawn by the fact that the work had never been done before. She brought her young daughter to the lab on weekends and evenings. She is credited with popularising the term “software engineering” to describe the complexity of the task and to place coding on equal footing with hardware design. She authored more than 130 publications and later founded her own company after leaving MIT in the mid-1970s.

The software’s reliability was tested during the Apollo 11 landing on 20 July 1969. As the lunar module Eagle descended, the Apollo Guidance Computer became overloaded by an unexpected radar switch. Hamilton’s priority display system alerted the crew and allowed the computer to continue the critical landing sequence rather than abort. President Barack Obama cited that moment when he awarded her the Presidential Medal of Freedom in 2016. “Our astronauts didn’t have much time, but thankfully they had Margaret Hamilton,” he said.

MIT’s interim head of the Department of Aeronautics and Astronautics, Olivier de Weck, called any description of her as a pioneer an understatement. She worked at a time when the field was in its infancy and both wrote advanced code and led a team that produced one of the most complex systems of its era. NASA Administrator Jared Isaacman noted that her work made the first journeys to the moon possible. The Smithsonian National Air and Space Museum’s Andrew Meade McGee said her coding foresight created the logical basis for many systems still used in aerospace.

Hamilton is survived by her daughter, a son-in-law, two grandsons, and four great-grandchildren. The software she directed guided every crewed Apollo flight. The methods she helped establish became standard practice in an industry that did not yet have a name when she began the work.