Octavia Spencer could not believe that 'Hidden Figures' was a true story.
The actress plays Dorothy Vaughan in the drama about three African-American women who were on the team that helped to launch astronaut John Glenn into orbit in the 1960s and was shocked that she had never heard of the women before.
She told The Wrap: "Honestly, I thought it was historical fiction because I had grown up with the narrative of what happened in the space race and we've seen so much archival footage, I thought the fact that we never heard of these women, it had to be fiction. And then I felt compelled to be part of the story because I feel like these women are unsung heroes."
And Taraji P Henson - who plays NASA mathematician Katherine Johnson - admitted she felt a duty to star in the movie.
She said: "This movie I had to do, I just felt like it was my duty. We always celebrate the astronauts, but we don't celebrate the mathematicians behind it. But I didn't know that these women existed and I was like, 'Why are we just learning about them?' And I couldn't wait to meet Katherine Johnson, she's still very much alive. She's 98 now.
"What struck me most was her humility. She found the 'we' in 'I.' Because John Glenn asked for Katherine in a time when it was very difficult for women, especially black women - [we] couldn't even vote. She focused on solutions, not problems."
The movie, which has been directed by Ted Melfi, also stars Janelle Monáe.