Katherine Johnson, who died Monday at 101, is remembered as a "NASA mathematician, trailblazer in the quest for racial equality, contributor to our nation's first triumphs in human spaceflight and champion of STEM education."
As a "human computer," Johnson famously double-checked the numbers for astronaut John Glenn's 1962 orbital mission. Glenn himself asked for Johnson to re-run the computer calculations prior to his launch. This came at a pivotal moment in the space race between the US and the Soviet Union. Glenn became the first American to orbit the Earth.
She received the Presidential Medal of Freedom in 2015.
Johnson's work and legacy came into sharper focus for many in the 2016 book Hidden Figures: The American Dream and the Untold Story of the Black Women Who Helped Win the Space Race. The nonfiction book was adapted into the 2016 movie Hidden Figures.
"When asked to name her greatest contribution to space exploration, Katherine Johnson talks about the calculations that helped synch Project Apollo's Lunar Lander with the moon-orbiting Command and Service Module," NASA says in a biography of Johnson.
NASA quoted Johnson in a statement issued at the time of the Presidential Medal of Freedom honor: "I counted everything. I counted the steps to the road, the steps up to church, the number of dishes and silverware I washed … anything that could be counted, I did."
Johnson's life counted, immeasurably.