On July 20, 1969, during the Apollo 11 mission, the lunar module Eagle faced a critical problem. As it descended toward the moon, the onboard computer began flashing warning signals. With only 30 seconds of fuel left, the mission was on the brink of failure. But thanks to the software created by Margaret Hamilton and her team, the system was able to handle the situation and guide Neil Armstrong and Buzz Aldrin to land safely.

This was a huge accomplishment, especially considering how basic computers were in the 1960s. The Apollo spacecraft’s computer only had 72 kilobytes of memory—far less than what we use on modern phones. Programmers had to use punch cards to input data, and the computers were so big that they took up entire rooms. Despite these limitations, Hamilton and her team developed software that could prioritize important tasks and fix errors automatically.

Margaret Hamilton, just 32 years old at the time, led the software development team at MIT. Her journey to NASA started with her love for math and problem-solving. After graduating, she worked at MIT on weather prediction software and systems to track enemy aircraft. When she heard NASA was hiring programmers for the moon missions, she knew she had to be part of it, even though it meant postponing graduate school.

Hamilton’s work was not just about coding; she focused on making the software handle unexpected problems. For example, her young daughter once accidentally crashed a simulator by pressing the wrong button. Hamilton suggested adding safety features to prevent such mistakes, but her idea was dismissed because “astronauts wouldn’t make mistakes.” Later, during the Apollo 8 mission, an astronaut made the same mistake, proving Hamilton’s idea was right. This led to updates in the software for future missions.