Katherine Johnson
Mathematician whose calculations for Nasa put the first American into space – and man on the Moon
KATHERINE JOHNSON, who has died aged 101, was the human “computer” charged with calculating the paths of the flights that sent Americans into space and – eventually – put Neil Armstrong on the Moon. At the Langley Research Center in Hampton, Virginia, she was one of a team of young female mathematicians, many of them former teachers, who performed the time-consuming calculations that determined a spacecraft’s orbit trajectory. The centre was run by the National Advisory Committee for Aeronautics (NACA), the precursor to Nasa, which had pursued a policy of hiring women since the 1930s – in part to free up male aeronautical engineers for other research projects.
In the days before sophisticated computer programmes, these human “computers” relied on slide rules and graph paper to crunch their data. Many, Katherine Johnson included, were black women, hired in the wake of Franklin Roosevelt’s executive order prohibiting racial discrimination in the national defence industry.
In 1958, the same year that NACA became Nasa, Katherine Johnson secured a promotion to the administration’s all-white, all-male Space Task Force, which was gearing up to launch the first American citizen, Alan Shepard, into orbit. The calculations for this mission, Katherine Johnson recalled, were “Easy … it was just a matter of shooting him up and having him come back down.”
She went on to plot the trajectory for John Glenn’s complete orbit around the Earth in 1962. Glenn had asked for her personally, as he doubted the ability of Nasa’s enormous, newly purchased mechanical computer to do the job. As a further reassurance, Katherine Johnson produced navigational charts for astronauts to use in the event of a systems failure.
By the time of the Apollo mission to the Moon, in 1969, the mathematical tasks involved had become rather more complicated. Katherine Johnson’s job was to calculate the trajectories that would put a craft into lunar orbit, drop a lander safely on to the Moon’s surface, and return the mission to Earth. The high-stakes nature of the work was compounded by its sheer novelty; forced, quite literally, to write the first textbook on lunar landings, Katherine Johnson and her colleagues often had to rely on instinct. She was cheered on in this by the astronauts whose lives were in her hands, one of whom assured her: “I’ll take Kate’s hunches anytime.”
On the day of the landing itself she was attending a sorority meeting in Pennsylvania, and watched the event on television – along with half a billion people around the world. Only a few women in the room knew of the crucial role she had played in the mission. Nasa later presented her with a souvenir flag that had returned from the Moon with Neil Armstrong and his crew. Later still, aged 97, she received the Presidential Medal of Freedom, America’s highest civilian honour, from Barack Obama.
The youngest of four children, she was born Katherine Coleman on August 26 1918 in White Sulphur Springs, West Virginia. Her father Joshua held various jobs as a lumberman and farm hand, while her mother Joylette had worked as a teacher.
Though Joshua had received no formal schooling past the age of 12, he could solve mathematical problems at great speed and was determined that all his children should benefit from a college education. To this end, every September the whole family moved 120 miles to a rented house in an area where there was a black high school. They would return to Sulphur Springs in the summer to do the harvest work that provided their main income.
Early on, it was apparent that Katherine’s gift with numbers surpassed even her father’s. She was enrolled at high school aged 10; four years later she started at West Virginia State College, where she took every mathematics course available. She graduated in 1937 and worked for a time as a teacher in Marion, Virginia, where Jim Crow’s racial segregation laws were more rigidly enforced than they had been in her home town. It was not until 1952 that she learnt of opportunities for black female mathematicians at Langley Research Center, where she was initially put to work analysing the data from the black boxes of crashed aircraft.
At that time the job of junior “computer” was classed as an “unprofessional” one, meaning that women fulfilling the role were paid far less than their male counterparts, the “professional” junior engineers. Undeterred, Katherine Johnson soon won the right to sit in on the engineers’ meetings.
“At first they said no,” she recalled. “I said, “Is there a law?’” In 1953 she and a colleague were “loaned out” from the computing pool to assist with calculation in NACA’S flight research division – the nucleus of the American space programme. The loan became a permanent position on the Space Task Force.
In all, Katherine Johnson co-wrote 26 scientific papers during the 1960s and 1970s, several of which established key principles for successful manned flights. Determination of Azimuth Angle at Burnout for Placing a Satellite over a Selected Earth
Position (1960) provided a theoretical basis for John Glenn’s 1962 trip, as well as being the first paper from Nasa to have a woman’s name on it.
In the later years of her career she was charged with tracking the progress of various unmanned satellites. One of these, the Earth Resources Satellite, was used to detect the presence of minerals below the surface of the Earth. She retired in 1986, after 33 years of service, with three Nasa special achievement awards to her name.
Despite these accolades, the extent of Katherine Johnson’s role was scarcely acknowledged by the mainstream media during her professional career. Only one New York paper covered her story after Alan Shepard’s return to Earth (under the heading “Negro Math Expert Helped Launch US Spaceman”). It was not until her ninth decade, when footage of her various talks on the role of women in science began to gain traction online, that her celebrity extended beyond Nasa. Annie Leibovitz photographed her for Vanity Fair, while the BBC included her in its 2016 list of the 100 most inspiring women worldwide.
In 2017 Hidden Figures, a film celebrating the achievements of Katherine Johnson (played by Taraji P Henson) and her fellow NACA mathematicians Dorothy Vaughn and Mary Jackson, was released to considerable attention.
Katherine Johnson’s first husband was James Francis Goble, whom she married in 1939. They had three daughters. He died of a brain tumour in 1956 and she married, secondly, Lt-col James Johnson, a Korean War veteran.