Katherine Johnson calculated rocket trajectories for NASA’s early crewed spaceflights at the Langley Research Center.
Johnson joined the National Advisory Committee for Aeronautics, later NASA, in 1953. She performed trajectory analysis for missions including Alan Shepard’s 1961 Freedom 7 flight, the first U.S. crewed spaceflight, and John Glenn’s 1962 orbital mission.
Before Glenn’s flight, Johnson checked the electronic computer’s orbital calculations by doing the mathematics herself. Glenn reportedly asked that she verify the numbers before he flew, illustrating the importance of independent calculation during the transition from human computing to electronic computers.
Johnson also contributed to Apollo 11 mission planning and the Space Shuttle program. She is sometimes grouped with NASA’s “human computers” without distinction, but her specialty was celestial navigation and trajectory mathematics.