On February 24, 2020, NASA took to Twitter to mourn the loss of Katherine Johnson, a pioneering mathematician who calculated rocket trajectories and Earth orbits for America’s earliest space missions. Johnson died in her retirement home at 101, and NASA celebrated her life, honoring her “legacy of excellence that broke down racial and social barriers.”

Johnson made the most of limited educational opportunities. Her fascination and gift for numbers allowed her to accelerate academically. In an era where most towns did not offer classes for African-Americans after eighth grade, Johnson entered high school at just 10 years old and graduated with degrees in mathematics and French at 18.

Her career with NASA’s predecessor, the National Advisory Committee for Aeronautics, began in 1953. When NASA was formed, Johnson calculated the trajectory of Alan Shepard’s 1961 journey into space, the first in US history. She also verified the calculations for John Glenn’s orbit around Earth just a year later – another first for the country. Glenn asked for Johnson specifically and refused to take off until she gave the green light after looking over the numbers made by new electronic computers.

Despite the importance of computers at NASA, Johnson’s reputation for her skill and accuracy led her to perform calculations in 1969 for the historic Apollo 11 voyage to the moon. Until her retirement in 1986, Johnson continued to help NASA develop its Space Shuttle program and Earth Resources Satellite.

Johnson was awarded the Presidential Medal of Freedom in 2015 by Barack Obama, who cited her in his State of the Union address as an example of the country’s spirit of discovery.

The pivotal roles of Johnson and other African-American women at NASA were portrayed in the award-winning 2016 film, Hidden Figures. Her expertise, leadership, and bravery made it possible for American astronauts to take their first steps in space that they now follow on their journey to Mars.