We guarantee your reaction to this will be: why didn’t we hear about this before?

Imagine, it’s the Jim Crow South, mid-20th century. Black girls – women but they were called girls then – were working at Langley Research Center in Hampton, Virginia. But they weren’t maids or service staff. They were doing the math that made planes safer and, in a few years, they were the human computers that helped put men on the moon. As black women at the time, they had two glass ceilings to break through. Math was considered “women’s work,” if you can believe it.

Listen to this NPR interview with Margot Lee Shetterley, a Hampton, Va., native and daughter of a former Langley scientist, who discusses her new book Hidden Figures: The American Dream and the Untold Story of the Black Women Mathematicians Who Helped Win the Space Race. The book has already been adapted for big screen; the film starring Taraji P. Henson, Octavia Butler and Janelle Monae premieres in January.

From the interview:

You know, the Russians had got a real head start into space, America was playing catch up. And this was also a moment where electronic computers were taking over the task of much of the calculating that was necessary for these increasingly complex missions.

But as sort of a hand off moment between human computers and electronic computers, John Glenn asked Katherine Johnson — he actually asked “the girl” — all of the women working at that time were referred to as “girls.”

And he said: “Get the girl to do it, I want this human computer to check the output of the electronic computer and if she says they’re good, you know, I’m good to go as part of one of my pre-flight check lists.”

So the astronaut who became a hero, looked to this black woman in the still segregated south at the time as one of the key parts of making sure his mission would be a success.