Billy Hesterman

When Neil Armstrong took that first historic step onto the Moon in 1969, the world knew his name. Far fewer people knew the name of the woman whose work helped make sure he got there alive. Her name was Margaret Hamilton, and today we learned that she has died at the age of 90. Hamilton was a mathematician and computer scientist who led the team at MIT responsible for developing the onboard flight software for NASA's Apollo missions. At a time when computers were enormous, their capabilities were limited, and software engineering was barely recognized as a profession, she was helping invent the technology that would carry human beings to another world. And she wasn't just writing code. She was anticipating disasters that nobody else had thought about. During the final descent of Apollo 11, as Armstrong and Buzz Aldrin approached the lunar surface, the spacecraft's computer suddenly began sounding alarms. It was being overwhelmed with tasks, and there was a real possibility that the landing would have to be aborted. But Hamilton and her team had anticipated something like this. Their software was designed to recognize which tasks were essential and which could wait. When the computer became overloaded, it automatically discarded less important work and concentrated on keeping the spacecraft flying. The landing continued. Armstrong and Aldrin reached the lunar surface. And history was made. One of the most famous photographs of Hamilton shows her standing beside an enormous stack of printed computer code, nearly as tall as she was. It represented the extraordinary amount of work that went into making those missions possible. She also helped popularize the term "software engineering," insisting that developing computer programs deserved the same professional recognition as other branches of engineering. It was an idea that some of her colleagues initially laughed at. Today, virtually every aspect of modern life depends on the discipline she helped establish. In 2016, President Barack Obama awarded Hamilton the Presidential Medal of Freedom, recognizing her extraordinary contributions to science and human achievement. Margaret Hamilton never walked on the Moon. She never wore a spacesuit or became a household name like the astronauts whose lives depended on her work. But when humanity accomplished something that had seemed impossible for thousands of years, her fingerprints were all over it. She helped us reach the Moon, and her legacy will live on in the technology we use every single day. Rest in peace, Margaret Hamilton.