_(2).jpg)
Margaret Hamilton
1936–2026 · Computer scientist and software engineer
A computer scientist who led the team that wrote the onboard flight software for NASA's Apollo missions, including the landing of Apollo 11 on the Moon.
“There was no choice but to be pioneers.”
Why is this scientist famous?
Leading the team that wrote the Apollo flight software and helping establish software engineering as a discipline.
Hamilton led the MIT team responsible for the Apollo command-module and lunar-module onboard flight software. During Apollo 11, the guidance computer's overload-handling design allowed it to keep the highest-priority landing tasks running despite repeated alarms. She helped establish software engineering as a recognised discipline and is credited with popularising the term.
Margaret's story
Early Life
Born in Paoli, Indiana, Hamilton studied mathematics at Earlham College and originally planned to do graduate work in abstract mathematics. In 1959 she took a job at the Massachusetts Institute of Technology (MIT) to support her husband through law school, intending to return to graduate school later. Instead, she found herself working on weather prediction software — one of the first computerised forecasting systems — and never looked back.
Apollo and the AGC
In 1965 Hamilton joined MIT's Instrumentation Laboratory, which was developing the Apollo guidance system for the National Aeronautics and Space Administration (NASA). She later led the Software Engineering Division and was responsible for the onboard flight-software effort for the Apollo command and lunar modules. The Apollo Guidance Computer had 2,048 words of erasable memory and 36,864 words of fixed memory, so its software had to be compact and highly reliable.
Saving Apollo 11
During the Apollo 11 lunar landing on 20 July 1969, the guidance computer was overloaded by unnecessary rendezvous-radar activity and triggered repeated alarms. The asynchronous executive and restart protections developed for the Apollo software allowed the computer to resume its highest-priority tasks, while mission-control specialists correctly judged that the landing could continue. Hamilton led the onboard flight-software team and made important contributions to its error-detection and recovery approach.
Legacy
Hamilton is credited with popularising the term 'software engineering' at a time when software was not taken seriously as an engineering discipline. She later founded two software companies and received the NASA Exceptional Space Act Award in 2003. In 2016, President Barack Obama awarded her the Presidential Medal of Freedom, the highest civilian honour in the United States, for her contributions to the Apollo programme and to the field of software engineering.
What did they discover?
Apollo Guidance Software
Led development of the onboard software for the Apollo Guidance Computer, used in all Apollo missions including Apollo 11 — the first crewed Moon landing.
Priority Scheduling
Hamilton's team developed Apollo flight software that used priority-based task handling and restart protection, allowing the computer to resume its most important work during an overload.
Software Engineering as a Discipline
Helped establish software engineering as a respected field, insisting on rigorous testing, error detection, and system-level design decades before these became standard practice.
Amazing facts
She popularised the term 'software engineering' at a time when the field was not considered real engineering.
The Apollo Guidance Computer had only 4 KB of RAM — less than a single email today.
The overload-handling and restart protections in the Apollo flight software helped the guidance computer continue its highest-priority landing tasks during the Apollo 11 alarms.
She received the Presidential Medal of Freedom from President Obama in 2016.
She was 32 years old when she led the software team for the first Moon landing.
A famous photograph shows her standing next to a stack of Apollo code printouts taller than she is.
Timeline
Born in Paoli, Indiana
Began programming weather prediction software at MIT
Joined the MIT Instrumentation Laboratory for the Apollo programme
Apollo 11 landed on the Moon using her team's software
Founded Hamilton Technologies, her own software company
Received the NASA Exceptional Space Act Award
Received the Presidential Medal of Freedom
Awards & honours
Related Super Scientists
Katherine Johnson
1918–2020 · Mathematician
Calculating and verifying trajectories for historic NASA missions, including Alan Shepard's first American spaceflight, John Glenn's orbital mission and Apollo 11.
Ada Lovelace
1815–1852 · Mathematician
Publishing influential 1843 Notes on Charles Babbage's Analytical Engine, including a detailed algorithm for calculating Bernoulli numbers and a visionary description of uses beyond arithmetic.
Grace Hopper
1906–1992 · Computer Scientist & Naval Admiral
Developing one of the earliest compilers and pioneering word-based programming languages that helped make computers easier to program.
