Apollo moon mission scientist, Margaret Hamilton, dead at 90

Margaret Hamilton, a computer scientist whose software guided NASA’s Apollo program, has died at 90, according to Massachusetts Institute of Technology, or MIT.

MIT announced Wednesday that Hamilton, best known for leading the software engineering team at MIT’s Instrumentation Lab during NASA’s Apollo program, died on Sept. 30. Hamilton authored over 130 publications and worked at MIT from 1959 until the mid-1970s, before becoming a successful computing entrepreneur and CEO.

President Barack Obama recognized her with the 2016 Presidential Medal of Freedom, noting that Hamilton’s software architecture led to giant leaps for humankind, writing the code that helped America set foot on the moon.

How did she save the Apollo mission? Hamilton told Hack the Moon, an educational campaign to highlight the contributions of engineers to lunar missions, that her daughter accidentally triggered a pre-launch program called P01 during a simulator flight. That led Hamilton to suggest software changes to prevent the same error during a real mission. Hamilton’s warning was initially dismissed, but when astronaut Jim Lovell made the same mistake during Apollo 8, Hamilton’s team fixed the problem, and her changes were added—an early example of so-called defensive programming.

Hamilton’s most famous contribution to the Apollo program came during the Apollo 11 mission to land on the moon in July 1969, according to MIT. Shortly before the Eagle module was set to land on the lunar surface, the onboard computer detected an error: The computer overloaded due to a hardware switch fault, effectively jeopardizing the system’s ability to handle the complicated landing procedure. But Hamilton and her team engineered software that was able to streamline operations, shutting down low-priority background tasks to focus solely on mission-critical operations. Because of her quick thinking, Mission Control greenlit the first manned lunar landing, making it possible for Neil Armstrong and Buzz Aldrin to walk on the moon.

Hamilton is survived by a daughter, her son-in-law, two grandsons, four great grandchildren, and three siblings, according to MIT.