The bold story of Katherine Johnson, an African-American mathematician who worked for NASA during the space race and was depicted in the filmHidden Figures.You've likely heard of the historic Apollo 13 moon landing. But do you know about the mathematical genius who made sure that Apollo 13 returned safely home?As a child, Katherine Johnson loved to count. She counted the steps on the road, the number of dishes and spoons she washed in the kitchen sink, everything! Boundless,