On July 20, 1969, Apollo 11 was just minutes away from touching down on the surface of the moon. Engineers in Houston, TX, and in the lab at MIT, including a young software engineer named Margaret, were anxiously waiting to see if their brand-new computer software would hold up. So far, everything with the lunar module’s on-board computers had gone according to plan, with no major hiccups. So the engineers in Houston were startled when error messages suddenly began popping up. The computer, built with software written by a team of engineers from MIT headed by Margaret, was being overwhelmed with a series of unnecessary tasks rather than performing its real job of landing the lunar module. The panicked astronauts sent a message back to Houston. Should they abort the landing? Would the computer fail at the last minute?
Margaret was born Margaret Heafield on August 17, 1936 in Paoli, Indiana. As a young girl, she excelled in science and math, both subjects not considered typical for women to like. She attended Earlham college in 1958 to get a bachelor’s degree in mathematics. While she was there, she met her husband, James Cox Hamilton. After Margaret graduated, she was accepted to the lab at MIT as a software engineer. The plan for Margaret was to work three years to support her husband’s degree at Harvard Law, and then the pair would switch so Margaret could pursue a graduate degree in abstract math. However, Margaret would soon find herself caught up in one of the biggest revolutions to ever sweep the technology industry.
During her time at MIT, she got her first introduction to the world of software engineering. She worked on projects such as SAGE, which was a computer program designed to search for “unfriendly” aircraft, a very early form of homeland security. Margaret called her work on SAGE as a “jumping-off point”, where she became interested in the importance of software reliability. This early work under pressure undoubtedly served her well during her next major project: creating software for the Apollo 11 moon mission.
In 1961, MIT’s instrumentation lab received the contract for the Apollo guidance and control systems. In order to take advantage of what she saw as a once-in-a-lifetime opportunity, Margaret put her plans for a graduate degree on hold and applied for a position with the Apollo program. She was hired on the spot. As Margaret recalled, it was like the “Wild West.” She and her colleagues were coding programs for takeoff, navigation, flight plans, and the moon landing, all without a guidebook or a clear set of rules. There were no classes in computer science and no precedent for the programs Margaret was creating. As she said of herself and her fellow engineers, they “had no choice but to be pioneers.”
In 1965, Margaret was put in charge of all onboard flight software for the Apollo mission. As a female engineer at NASA in the 1960’s, Margaret was already unique. As a female engineer at NASA in the 1960’s responsible for a major coding project like Apollo, Margaret was unprecedented. She was also unusual in the fact that she was a working mother in the 1960’s. While working on the Apollo program, Margaret would often bring her young daughter, Lauren to the lab at night and on the weekends. Margaret was often asked how she could stand to leave her child all day while she was at work. But to Margaret, the work that she was doing was important, and so she created a balance that allowed her to spend time with her daughter and to give her absolute best at her job.
The flight software that Margaret’s team was coding had to be absolutely perfect. The astronauts needed to be able to rely on it to get them safely to the moon and back, something no one had ever attempted to do before. Coding in Margaret’s day was slightly more complicated than typing it out on the computer. Every line of the program had to punched in a stack of cards, which would then be run through a massive computer overnight. The picture on the left shows Hamilton standing next to a massive stack of code written for the Apollo program. Every line of that code had to be tested and retested according to the rigorous standards Margaret put in place. As she and the other programmers knew, there would be no second chances if the software failed mid-flight.
This intense testing proved invaluable when the time came for the moon landing. As the computer’s error messages were popping up, Margaret and the other engineers knew that the software would not fail. It had been programmed specifically to perform the most important task in case of a shutdown. In this instance, that task was landing the lunar module. Houston advised the astronauts to continue with the landing process, and history was made.
Margaret Hamilton is a true modern pioneer. She excelled in science during a time when women were often excluded from tech jobs, particularly in the brand-new field of computer science. Engineers like Margaret Hamilton were responsible for contributing to a massive leap in software technology that resulted in the basis for the computers we have in the present day. In 2016, Margaret was awarded the Presidential Medal of Freedom by President Obama for her contributions to the Apollo mission. Today, Hamilton is the creator of Hamilton Technologies, a tech company in the same neighborhood as MIT, where she got her start as a software engineer. She has encouraged hundreds of women and girls to enter the tech industry, where their accomplishments have the chance to be just as important and legendary as Hamilton’s.