African American mathematician Katherine Johnson began working at the National Advisory Committee for Aeronautics in 1953 in a position that was classified as “subprofessional,” not far outranking a secretary or janitor.

Nevertheless she persisted: using a slide rule or mechanical calculator in complex calculations her job was to check the work of her superiors — engineers who, unlike her, were white and male.
Her title was “computer.”

Mrs. Johnson, who died Feb. 24 at 101, went on to develop equations that helped the NACA and its successor, NASA, send astronauts into orbit and, later, to the moon. In 26 signed reports for the space agency, and in many more papers that bore others’ signatures on her work, she codified mathematical principles that remain at the core of human space travel.

In 2015, President Barack Obama awarded her the Presidential Medal of Freedom — the country’s highest civilian honor. The next year, her research was celebrated in the best-selling book “Hidden Figures” by Margot Lee Shetterly and the Oscar-nominated film adaptation starring Taraji P. Henson, Octavia Spencer and Janelle Monáe.