The History Column: Katherine G. Johnson
The 2016 movie Hidden Figures gave the general public a fascinating glimpse into the world of NASA’s African American female ‘computers’ (mathematicians). Margot Shetterly’s book, upon which the movie was based, explores the lives and careers of several of these women, one of whom was Katherine Johnson. This author is indebted also to Katherine Johnson’s excellent autobiography that she wrote at the age of 100!
Born on August 26, 1918, near the city of White Sulphur Springs, West Virginia, Katherine Coleman displayed her academic giftedness at an early age. After a single summer in kindergarten at age 4 she was immediately placed into the second grade, later skipped the fifth grade and started high school at the age of 10. At the age of 18, Katherine graduated from West Virginia State College (now West Virginia State University) having dual-majored in mathematics and French.
After 16 years of public-school teaching, getting married and starting a family, Katherine was hired by NACA (predecessor to NASA) at their facility in Hampton, Virginia and joined the West Area Computing group in 1954. The West Area group consisted of African Americans, whereas the East Area Computing employees were White. Labor requests for particularly challenging mathematical tasks were typically sent to the West Area since the African Americans were only hired if they had graduated from college with a high GPA and NACA particularly recruited those who had earned honors in math. By contrast, no college education was required for those hired into the East group.
Katherine excelled in the work and made it her mission to understand the science and engineering behind it. She became a well-respected and highly valued member of the team of engineers she worked with. She started working in the Maneuver Loads Branch of the Flight Research Division and assisted with pioneering work characterizing the effects of wake turbulence. After the Space Race began, she supported NASA’s Mercury, Gemini and Apollo programs. Later work included interplanetary missions and work that anticipated the development of large space structures such as the International Space Station.
One of her strengths was the computation of spacecraft flight trajectories. In the preparations leading up to John Glenn’s orbital flight in 1962, Katherine and engineer Ted Skopinski worked out the spherical trigonometry needed to ensure that an orbiting vehicle would arrive at a desired position after a small number of orbits (the desired position being the start of the de-orbiting maneuver to ensure the vehicle landed at a chosen location). The critical parameter was the azimuth angle (angle with respect to truth north of the vehicle’s horizontal velocity vector component) at burnout (point at which the thrusters stopped). This angle is denoted by ψ in the figure on the next page. The mathematics would be fairly straightforward if the Earth was spherical. However, when the oblateness of the Earth is considered, simple closed-form expressions are no longer possible and an iterative procedure was derived. The resulting paper not only provided a key piece of the theoretical foundation for Glenn’s successful flight, it also was the first research report published from NASA’s Flight Research Division co-authored by a woman.
Katherine Johnson retired from NASA in 1986 and spent much of the ensuing years encouraging young people, especially women, to go into STEM fields. She died on February 24, 2020 at the age of 101, having left a distinguished legacy of the accomplishments that are possible when a talented person is given the chance to be educated and to contribute.
Further information may be found in:
Shetterly, M., Hidden Figures, William Morrow, New York, 2016.
Johnson, K., Reaching for the Moon – The Autobiography of NASA Mathematician Katherine Johnson, Atheneum Books for Young Readers, New York, 2019.
Skopinski, T. and Johnson, K., ‘Determination of azimuth angle at burnout for placing a satellite over a selected Earth position,’ Technical Note D-233, NASA, September 1960.
Authored by Michael Braasch
Ohio University