Katherine Johnson, one of the NASA mathematicians portrayed in “Hidden Figures,” passed away Monday according to the administrator of NASA.

She was 101 years old.

NASA administrator Jim Bridenstime took to Twitter saying Johnson “was an American hero and her pioneering legacy will never be forgotten.”

In the 2016 Oscar-nominated film “Hidden Figures”, Johnson was portrayed by Taraji P. Henson. It is about trailblazing black women whose work at NASA was vital during the Space Race.

The film also features Octavia Spencer as mathematician Dorothy Vaughan and Janelle Monáe as engineer Mary Jackson.

Johnson started working at NASA’s predecessor, the National Advisory Committee for Aeronautics’ in 1953 at the Langley laboratory in Virginia. She did trajectory analysis for Alan Shepard’s 1961 mission Freedom 7, which was also considered by NASA as America’s first human spaceflight.

In addition, she was also the first woman in the Flight Research Division to be given credit as an author of a research report for her work with Ted Skopinski on defining the equations that describe an orbital spaceflight.

She was popularly known for her work that is an integral help to the first American orbital spaceflight piloted by John Glenn.

The 1962 flight needed the construction of a “worldwide communications network” connecting tracking stations around the world to computers in Washington, D.C., Cape Canaveral, and Bermuda.

But according to NASA, astronauts then weren’t sure about “putting their lives in the care of the electronic calculating machines, which were prone to hiccups and blackouts.” So Glenn told engineers to “get the girl,” referring to Johnson, to run the computer equations by hand.

Johnson remembered Glenn saying:

“If she says they’re good, then I’m ready to go.”

In a statement, NASA says:

“Glenn’s flight was a success, and marked a turning point in the competition between the United States and the Soviet Union in space.”

But according to NASA, whenever people asked Johnson to name her greatest contribution to space exploration, she always talks about the calculations that helped synch Project Apollo’s Lunar Lander with the moon-orbiting Command and Service Module.