Margaret Hamilton, the computer scientist who led development of the onboard flight software for NASA's Apollo program, died on September 30 at the age of 90, according to MIT News, which announced her death on October 7. The cause of death was not disclosed. Hamilton worked at MIT from 1959 until the mid-1970s, rising from a temporary meteorology programming job to lead the Software Engineering Division of the Instrumentation Lab. By 1968 she was assistant director in charge of the Command and Service Module team, with more than 400 people working on Apollo's software under her direction.

Hamilton is credited with popularizing the very term "software engineering." According to MIT News, she began using the phrase to distinguish software from hardware engineering, and told El Pais in 2018 that at first "it was considered to be quite amusing. It was an ongoing joke for a long time. They liked to kid me about my radical ideas." CNN notes she is credited as one of the founders of the field, helping establish it as a professional practice. Over her career she authored more than 130 publications. In 1976 she founded Higher Order Software, then Hamilton Technologies a decade later, whose flagship product is the Universal Systems Language, built on error prevention and fault tolerance. She received the NASA Exceptional Space Act Award in 2003 and the Presidential Medal of Freedom in 2016.

Hamilton was the first programmer hired for MIT's Apollo project and its first female programmer, joining in 1965 after answering a newspaper ad seeking people to develop software to "send man to the moon." The 2003 NASA award nomination, per CNN's report, highlighted that her "concepts of asynchronous software, priority scheduling, end-to-end testing, and man-in-the-loop decision capability... became the foundation for ultra-reliable software design." Draper, the lab that spun out of MIT after Apollo, said in a statement that she helped ensure astronauts "landed safely on the lunar surface and safely returned home." For spaceflight readers, her legacy is the reliability engineering that every crewed mission since has inherited — the idea that software must defend itself when everything else fails. MIT called her a "computing pioneer" whose influence reached far beyond the missions.

Tributes poured in from across the space community following MIT's announcement. MIT's Olivier de Weck said that calling Hamilton a pioneer "would be a dramatic understatement," noting she led a team using nascent technology to build "one of the most complex systems humanity had ever achieved." According to The Guardian, Hamilton is survived by her daughter Lauren, a son-in-law, two grandsons and four great-grandchildren. Per the report by Marta Kowalska at news.lavx.hu, a memorial service will take place in the spring in Cambridge, Massachusetts, and Hamilton's honors also included the Computer History Museum Fellow Award in 2017 and the 2015 addition of the Apollo software to GitHub. In 2017 she even became an official Lego Minifigure in the Women of NASA set. Her life's arc — from Indiana-born mathematician to the woman who wrote the code that put America on the moon — closes one of spaceflight's founding chapters.