Women in STEM: Katherine Johnson

This month, we are highlighting NASA mathematician Katherine Johnson, who was instrumental to the early success of NASA. Johnson was a human “computer,” using math to calculate launch angles and trajectories for the early NASA spaceflights. She was instrumental in John Glenn’s first orbit of the Earth and worked for the space program for 33 years.

Engineers from those groups formed the core of the Space Task Group, the NACA’s first official foray into space travel. Johnson, who had worked with many of them since coming to Langley, “came along with the program” as the NACA became NASA later that year. She did trajectory analysis for Alan Shepard’s May 1961 mission Freedom 7, America’s first human spaceflight.

In 1960, she and engineer Ted Skopinski coauthored Determination of Azimuth Angle at Burnout for Placing a Satellite Over a Selected Earth Position, a report laying out the equations describing an orbital spaceflight in which the landing position of the spacecraft is specified. It was the first time a woman in the Flight Research Division had received credit as an author of a research report.

In 1962, as NASA prepared for the orbital mission of John Glenn, Johnson was called upon to do the work that she would become most known for. The complexity of the orbital flight had required the construction of a worldwide communications network, linking tracking stations around the world to IBM computers in Washington, Cape Canaveral in Florida, and Bermuda.

The computers had been programmed with the orbital equations that would control the trajectory of the capsule in Glenn’s Friendship 7 mission from liftoff to splashdown, but the astronauts were wary of putting their lives in the care of the electronic calculating machines, which were prone to hiccups and blackouts.

As a part of the preflight checklist, Glenn asked engineers to “get the girl”—Johnson—to run the same numbers through the same equations that had been programmed into the computer, but by hand, on her desktop mechanical calculating machine. “If she says they’re good,’” Katherine Johnson remembers the astronaut saying, “then I’m ready to go.” Glenn’s flight was a success, and marked a turning point in the competition between the United States and the Soviet Union in space.

When asked to name her greatest contribution to space exploration, Johnson would talk about the calculations that helped synch Project Apollo’s Lunar Module with the lunar-orbiting Command and Service Module. She also worked on the Space Shuttle and the Earth Resources Technology Satellite (ERTS, later renamed Landsat) and authored or coauthored 26 research reports. She retired in 1986, after 33 years at Langley. “I loved going to work every single day,” she said. In 2015, at age 97, Johnson added another extraordinary achievement to her long list: President Barack Obama awarded her the Presidential Medal of Freedom, America’s highest civilian honor.