Credit: NASA

Katherine Johnson has passed at the age of 101.

Katherine Johnson, a former mathematician for NASA who was known as a “human computer” during her career, passed away today. Johnson’s passing was announced on Twitter by NASA Administrator Jim Bridenstine.

Johnson was a driving force behind several of NASA’s most famous missions, calculating flight paths for the first moon landing and the space shuttle program. She originally worked at the National Advisory Committee for Aeronautics in 1953, where she calculated trajectories for the very first human space flight in 1961, a mission named Freedom 7. In situations where snap calculations were required, NASA techs would often retrieve Johnson to do the math by hand because they trusted her mind more than that of a computer. When John Glenn flew Friendship 7 in 1962, he personally requested Johnson to double-check the computer’s calculations before the launch.

In 2015, Johnson was awarded the Presidential Medal of Freedom by President Barrack Obama in a ceremony at the White House. “In her 33 years at NASA, Katherine was a pioneer who broke the barriers of race and gender, showing generations of young people that everyone can excel in math and science, and reach for the stars,” Obama said.

In 2016, Johnson was portrayed by Taraji P. Henson in Hidden Pictures, an Oscar-nominated film about the work of black women who made vital contributions to NASA’s work during the Space Race.