In 1943, Duchess Harris' grandmother began working at NASA. She was one of 11 black women mathematicians hired when there were no more qualified white men — many were off to war — nor white women available to work on beating the Soviet Union in the space race.

Few knew they were there. But astronaut John Glenn did. He sought them out to verify others' calculations. They were that good.

Their story is told in the movie "Hidden Figures," starring Janelle Monae, Taraji P. Henson and Octavia Spencer. It opens Friday.

Harris, a professor and chair of American studies at Macalester College in St. Paul, has written a book about how those black women resisted racism and sexism to support their families and, she said, "to advance a country where they were not full citizens." That book, which is aimed at middle-school students, is called "Hidden Human Computers: The Black Women of NASA."

Harris' grandmother, Miriam Daniel Mann, died two years before Harris was born, but Harris grew up with the stories. We talked with her about these "human computers" and how their work only now is coming to light.

Q: Describe the work done by your grandmother and the 10 other women.

A: They worked with slide rules doing the calculations to measure the distance and arc for the astronauts' return. The most fascinating issue was not getting them there; it was their return to Earth [such as hitting the right re-entry trajectory]. Were they going to be able to come back safely?

Q: They had human computers ­double-check the work of the electronic computers?

A: Yes, times have changed.

Q: You write that when a heavy workload caused black computers to be brought over to work with their white counterparts, they noted that everyone worked together well. Can racism become a nonissue when people with the same skills work toward the same goal? Or does it just get set aside in the service of the job?

A: For people who just wanted to get the work done, they could put racism aside. What a lot of people don't understand about the segregated South is that NASA was not allowed to put the racism aside. [By law, NASA had to provide segregated cafeterias, work areas, bathrooms.] …

Eventually, that led to the difference between white feminism and black feminism. When the war ended, the white men came back and were able to get good jobs. White women went to the suburbs and were able to stay home. When black men came back from the war, they didn't have an easy time getting jobs and weren't able to use their GI Bills to get homes in the suburbs. So my grandmother kept working at NASA until 1966 because the family needed the money. The black women never left.

Q: How did the stories of what your grandmother accomplished become real for you?

A: In college, I really started understanding what segregation was, not just socially, but legally. NASA saw that it was in their best interest that no one knew, so the women had a separate entrance and worked in a separate building and had separate bathrooms.

Some white computers never knew there were black computers doing the same work. I said to my mother, "This makes no sense." She said the government wanted to beat the Russians so much, they did whatever they could.

Q: You wrote about how your grandmother removed the "Coloreds" sign from the segregated cafeteria, only to have it reappear the next day.

A: She did, but when you see the movie, Kevin Costner [who plays the head of a NASA division] is given credit for taking the sign down. [In the movie, it's a bathroom sign.] My godmother saw an early screening and called. When she asked, "Are you sitting down?" I thought, "Oh, no." That's one reason I'm in collaboration with the BBC as part of an online educational project. They've showcased my digital archives on their website. I'm an academic, so I want historical accuracy.

Q: You've written, with Sue Bradford Edwards, another book for middle-schoolers, "Black Lives Matter," about the growth and history of that movement. Is there an intersection of the messages in each of these books?

A: The intersection is that it's important for people to know that we have done everything, but people also need to know what the obstacles have been. And that everyone wasn't brought along for the journey.

For my family, my grandfather was a college professor, my grandmother had a college degree. I'm third-generation, college-educated and still in my 40s. What is that if not the black elite? For me to act as if it isn't is disrespectful for black people who didn't have those opportunities.

Q: Are you frustrated that it's taken so long for this story to come to light?

A: I am an optimist, and I'm just delighted that it's all happening. I understand why it took so long. My life actually parallels my grandmother's life. I mean, it's taken this long for a black woman to write the story that this even happened. We need to liberate all of this. Without the humanities, this story could not be celebrated.

Kim Ode • 612-673-7185