She calculated the trajectory of man’s first trip to the moon, and was such an accurate mathematician that John Glenn asked her to double-check NASA’s computers. To top it off, she did it all as a black woman in the 1950s and ’60s, when women at NASA were not even invited to meetings.
And you’ve probably never heard of her.
Meet Katherine Johnson, the African-American woman who earned the nickname “the human computer” at NASA during its space race golden age.

see also http://www.nasa.gov/feature/katherine-johnson-the-girl-who-loved-to-count