It all started with a mysterious photograph.
In 2011, Mary Gainer worked as a historic preservationist for Nasa, and she stumbled on a 1943 picture of a thousand people standing in a huge building.
Scattered here and there was something unexpected: Women, some white and some black, in knee-length skirts and pompadour hairdos. There were too many to be secretaries, so who were they?
Another person was on a similar hunt - only Margot Lee Shetterly was a step ahead. Shetterly's father was a scientist who worked at Langley, so growing up in the 1970s and 80s, she was aware of the history of black women at Nasa.
"I knew them, and my dad worked with them. They went to our church and their kids were in my school," she says. "It was my husband who was like, 'What is this story? How come I've never heard about it?' "
This was a special story, she suddenly realised: black women living in Jim Crow-era Virginia hired by Nasa to do maths and research that would launch men into space.
Shetterly started poking around and linked up with Gainer, whose intern was compiling oral histories from former employees and their families. The stories of these math whizzes would become the book
, on which the movie is based.
Everyone knows what a computer looks like. But in the middle of the last century it looked different.
Women who used pencils and paper to calculate data from wind tunnel tests, among other research, were called computers. The female computers became invaluable as the needs for aircraft advancements gave way to a different kind of battle: beating, Russia to the moon.
The women who had these jobs may not have felt remarkable. They were happy to have work that paid better than the alternatives - teaching and nursing. The jobs were classified as "subprofessional," even though they entailed specialised math skills.
One such woman was Katherine G. Johnson. At 98, she still lives in Hampton, and she has emerged as the most high-profile of the "computers".
At Nasa, she worked on the life-or-death task of determining launch timing. Her calculations helped propel Alan Shepard into space and guided him successfully back to Earth; they landed Neil Armstrong on the moon and brought him home.
When Shetterly asked about her accomplishments, Johnson, a prodigy who graduated high school at 14, told her again and again, "I was just doing my job."