Margaret Hamilton, the software engineer who led development of Apollo's onboard flight software, died on September 30 at age 90. She joined MIT's Instrumentation Laboratory in 1965 and initially wrote software for uncrewed missions, including the abort procedure. A small program she named "Forget It" became notable when an uncrewed flight actually aborted, making her an "overnight expert."
Her team's software was critical during Apollo 11's descent. The guidance computer raised "executive overflow" alarms, but the software's restart protection allowed essential landing tasks to continue. Hamilton had earlier pushed for safeguards against operator error after her daughter crashed a simulation, but was initially overruled; an astronaut later made a similar mistake on Apollo 8, prompting changes.
Hamilton began calling herself a "software engineer" because coding wasn't taken as seriously as other engineering disciplines. After Apollo, she founded companies focused on fault-tolerant software and created the Development Before the Fact methodology and Universal Systems Language. In 2016, she received the Presidential Medal of Freedom.