Katherine Johnson(1918 — 2020)
Katherine Johnson
États-Unis
8 min read
African-American physicist, mathematician, and space engineer
Frequently asked questions
Key Facts
- Katherine Johnson naît en 1918 en Virginie-Occidentale dans une Amérique ségrégationniste qui lui interdit l'accès à de nombreuses écoles.
- Elle intègre la NASA (alors NACA) en 1953 comme 'calculatrice humaine', effectuant à la main des calculs de trajectoires spatiales.
- En 1962, John Glenn exige personnellement que Katherine Johnson vérifie les calculs de l'ordinateur avant son orbite autour de la Terre.
- Elle contribue aux calculs de trajectoire de la mission Apollo 11 qui permet à l'Homme de marcher sur la Lune en 1969.
- Elle reçoit la Médaille présidentielle de la Liberté en 2015 ; ses travaux sont portés à l'écran dans le film 'Les Figures de l'ombre' (2016).
Works & Achievements
Katherine Johnson manually calculated the ballistic trajectory for the first crewed American spaceflight. This calculation, completed in a matter of hours, allowed Alan Shepard to become the first American in space.
John Glenn refused to launch for his orbital flight until Katherine had personally verified the IBM computer's calculations. Her manual verification confirmed the data, and Glenn completed three orbits around the Earth.
The first official research report co-signed by Katherine Johnson at NASA, covering the equations for placing a satellite into orbit. It marked a first for a woman in the agency's flight research division.
Katherine Johnson contributed to the equations enabling Apollo 11's lunar landing and the safe return of the astronauts to Earth, representing the pinnacle of a career dedicated to space exploration.
During her final years at NASA, Katherine worked on trajectory calculations for the Space Shuttle program, contributing to the new generation of reusable space vehicles.
Anecdotes
Katherine Johnson had such mastery of orbital calculation that, during the Apollo 11 mission in 1969, astronauts and engineers would systematically verify her results by hand before trusting the computers. John Glenn, before his orbital flight in 1962, refused to launch until Katherine had personally checked the trajectories calculated by the machines.
Admitted to West Virginia University at just 18 years old, Katherine Johnson was one of the first three Black students accepted as part of the institution's desegregation. She earned her bachelor's degree in mathematics and French in 1937, graduating with honors before she had even turned 20.
At NASA (then called NACA), calculations were performed by 'human computers' — women tasked with doing the mathematics by hand. Katherine worked in a separate section reserved for African Americans, with segregated bathrooms and a separate cafeteria. Despite this, the exceptional quality of her work quickly earned her a place among the white engineering teams, breaking racial and gender barriers simultaneously.
Katherine Johnson co-authored a research report in 1960 on orbital trajectory equations, becoming one of the first women in the flight research division to sign an official NASA report. This technical document, titled 'Determination of Azimuth Angle at Burnout for Placing a Satellite Over a Selected Earth Position', remains a foundational contribution to astronautics.
In 2015, at the age of 97, Katherine Johnson received the Presidential Medal of Freedom from President Barack Obama, the highest civilian honor in the United States. She said her secret was simple: 'Love what you do and do it with excellence.' Her story was brought to the screen in 2016 in the film Hidden Figures, revealing to the general public the crucial role of these forgotten mathematicians.
Primary Sources
This report presents equations and procedures for determining the azimuth angle at burnout required to place a satellite over a selected earth position at a specified time.
Katherine Johnson's mathematical genius helped ensure that the United States won the Space Race. She calculated the trajectory for Alan Shepard, the first American in space, and was asked personally by John Glenn to run the numbers for his own historic Earth orbit.
We needed to be assertive as women in those days — assertive and aggressive — and the degree to which I was able to be, I'm happy to say, was rewarded.
Johnson contributed to the calculations for the trajectory analysis used for the first American crewed spaceflights, including Freedom 7 and Friendship 7, and later for the Apollo lunar missions.
Key Places
Katherine Johnson's hometown, in a state where access to secondary and higher education was extremely limited for Black children. Her father drove 200 km every year to allow her to continue her studies.
Katherine earned her bachelor's degree here at age 18, then became one of the first three Black students to join the graduate programs during desegregation in 1939.
The site of Katherine Johnson's entire career at NASA (1953–1986). It is here that she calculated the trajectories for America's first space missions, in buildings still marked by racial segregation.
Launch site for the Mercury, Gemini, and Apollo missions whose trajectories Katherine Johnson had calculated. Each liftoff represented the realization of her mathematical equations.
In 2017, NASA renamed the Langley computing building in her honor, officially recognizing the contribution of African-American women to the conquest of space.
Liens externes & ressources
Références
Œuvres
Calcul de la trajectoire du vol Freedom 7 d'Alan Shepard
1961
Vérification des trajectoires du vol Friendship 7 de John Glenn
1962
Rapport : Determination of Azimuth Angle at Burnout for Placing a Satellite Over a Selected Earth Position
1960
Calculs de trajectoire pour la mission Apollo 11
1969
Calculs pour le programme de navettes spatiales
1970-1986






