Margaret Hamilton, whose software helped land Apollo astronauts on the moon, has died

By Jackie Wattles, CNN

(CNN) — Margaret Hamilton, the groundbreaking researcher who helped create the field of software engineering and whose code helped land NASA’s Apollo astronauts on the moon to win the 20th century space race, has died. She was 90.

Hamilton’s former employer, the Massachusetts Institute of Technology, confirmed her death in a post from the department of aeronautics and astronautics. She died September 30, MIT reported. The cause of her death was not disclosed.

It was during her time working at MIT, where she took a job in 1959 and remained until the mid-1970s, that Hamilton managed the Software Engineering Division of the MIT Instrumentation Laboratory. The division landed a contract with NASA in 1961. She ultimately led a team of 100 engineers that designed the software to guide NASA’s Apollo missions.

Through her work, Hamilton is also credited as one of the founders of the field of software engineering — a term she popularized — by helping to establish it as a professional practice.

“To say Margaret Hamilton was a pioneer — to say she was ahead of her time — would be a dramatic understatement,” said Olivier de Weck, the Apollo Program Professor and interim head of the MIT Department Aeronautics and Astronautics, in a statement. “She was a software engineer at a time when that field was in its infancy, and she not only developed advanced code herself but also led a team in using that nascent technology to develop one of the most complex systems humanity had ever achieved.”

Hamilton was honored in 2016 with the Presidential Medal of Freedom by President Barack Obama for her contribution to science and space travel.

Pioneering error prevention

Hamilton was born in Paoli, Indiana, in 1936, according to MIT, and studied at the University of Michigan before receiving her degree in mathematics from Earlham College in Indiana. She took a job at MIT while her husband studied law at Harvard.

While working to develop critical onboard software for the spacecraft — both command modules and lunar landers — that completed NASA’s historic Apollo flights — Hamilton is credited with making the system more robust and accident-resistant.

One oft-cited failsafe she introduced was “the Lauren error,” according to MIT, which was named for her daughter and discovered when the then-4-year-old was fiddling with an Apollo command module simulator.

“She liked to play astronaut because she saw me playing that way in certain simulations we would run,” Hamilton later recalled in an oral history project. “This was in a hardware simulation because we wanted to try how the software worked with all the other things — the astronaut, the hardware. So I remember one time when Lauren’s simulation crashed and I thought, ‘Oh my god, how did that happen?’’’

So, Hamilton programmed backstops to prevent an astronaut from running into the same problem mid-flight, an issue that would have yielded far more dire consequences in space.

NASA pointed to one notable example where Hamilton’s work helped ensure mission success: During the famed 1969 Apollo 11 mission, Hamilton’s software overrode an errant attempt to swap the flight computer’s primary processing to a radar system.

The software’s intervention, which occurred just three minutes before the first ever touchdown on the lunar surface, “permitted the mission to safely continue,” NASA said.

After its work on Apollo, the MIT Instrumentation Lab spun off to become the Charles Stark Draper Laboratory, now known as Draper Laboratory.

Hamilton did not join the company, setting off instead to form her own company, but Draper’s CEO, Jerry Wohletz, said in a statement in MIT’s Wednesday announcement that Hamilton left an “indelible mark.”

“Through her leadership and contributions,” Wohletz said, “she helped ensure that Apollo astronauts landed safely on the lunar surface and safely returned home. We will honor her legacy at Draper forever.”

In 2003, Hamilton was also awarded NASA’s Exceptional Space Act Award.

The technologist who nominated Hamilton for the honor, Paul Curto, said at the time, “I was surprised to discover she was never formally recognized for her groundbreaking work.”

“Her concepts of asynchronous software, priority scheduling, end-to-end testing, and man-in-the-loop decision capability, such as priority displays, became the foundation for ultra-reliable software design,” he said.

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