On the morning of February 20, 1962, Katherine Johnson sat at her metal desk at NASA's Langley Research Center, a sharp pencil balanced between her fingers. The room hummed with the distant whir of the IBM mainframe, but her attention was fixed on the stack of handwritten equations spread before her. Astronaut John Glenn had personally requested that she re-calculate the orbital insertion numbers for his Friendship 7 mission —he trusted her mathematics over the computer's. She worked methodically, her steady loops and curves filling the graph paper, recalculating each trajectory component as the countdown ticked outside.

The air smelled of paper and coffee. Every decimal she confirmed brought the launch closer to certainty. Her hand never trembled. When she finally set down her pencil, the numbers matched perfectly, and she nodded. John Glenn would fly, and he would return. Katherine Coleman was born in White Sulphur Springs, West Virginia, in 1918. From an early age, she displayed an uncanny ability with numbers. By the time she was ten, she had sailed through elementary school and entered high school, a feat made possible by her parents' insistence on education despite the limited opportunities for African Americans in the segregated South.

Her father, a farmer and handyman, taught her the value of persistence. Her mother, a former teacher, nurtured her curiosity. Katherine graduated from West Virginia State College at eighteen with degrees in mathematics and French. She took a teaching job, but her real passion lay in solving complex problems. In 1953, a relative told her about openings at the National Advisory Committee for Aeronautics, and she applied. She was hired as a 'computer' —a human calculator— in the West Area Computing unit, a segregated group of Black women mathematicians. But the work itself was not the only challenge.

By the time she was ten, she had sailed through elementary school and entered high school, a feat made possible by her parents' insistence on education despite the limited opportunities for African Americans in the segregated South.

The West Area Computers were relegated to a separate building, forced to use separate bathrooms and dining facilities. Katherine and her colleagues were often given only the rawest data and expected to produce accurate results without full context. Despite these obstacles, she refused to let discrimination dim her focus. In 1956, she was temporarily assigned to the Flight Research Division, where she began to work directly with engineers on flight dynamics. Her supervisors quickly noticed that she asked sharp questions and spotted errors that others missed. Within a few years, she had been permanently transferred, one of the first Black women to break into the all-male white technical teams.

This transition was a quiet revolution —a shift not only of her career but of the rigid boundaries at Langley. When the speed of the Space Race intensified after the Soviet launch of Sputnik, Katherine's skills became indispensable. She contributed to the trajectory analysis for the Mercury missions, calculating the launch windows and return paths for astronauts like Alan Shepard. Her work on the 1961 mission that carried Shepard into space laid the groundwork for her later involvement with John Glenn. She used her understanding of analytic geometry and celestial mechanics to compute the precise points where the spacecraft would re-enter Earth's atmosphere.

Each calculation had to account for the Earth's rotation, the capsule's velocity, and the pull of gravity. She did it by hand, line by line, verifying the computer's outputs because she recognised that a machine could not flag its own errors. When a glitch briefly appeared in the computer data for Glenn's flight, it was her independent numbers that the flight director trusted to proceed. Even as her reputation grew, the struggle was not over. Colleagues sometimes doubted a Black woman's ability to grasp complex engineering. Katherine responded by delivering impeccable results, again and again.

She learned to navigate the institutional racism with grace and determination, finding allies among the engineers who valued her work. She once remarked that she didn't have time to focus on the barriers —she was too busy solving problems. This resilience was not born of naivety; she was acutely aware of the injustices, but she chose to channel her energy into proving her worth through her calculations, knowing that each accurate number chipped away at a stereotype. Her quiet steadfastness became a form of resistance that opened doors for those who came after her, including the women who would later become engineers and astronauts themselves.

Katherine Johnson's contributions extended far beyond Friendship 7. She went on to calculate the trajectories for the Apollo lunar module's rendezvous with the command module, helping to put Neil Armstrong on the Moon. She also worked on the Space Shuttle program and co-authored 26 research reports, breaking barriers each time. In 2015, President Barack Obama awarded her the Presidential Medal of Freedom, and she lived to see her story told in a book and a major motion picture, inspiring a new generation. One concrete detail: she was the first woman in the Flight Research Division to be credited as an author on a research report —a small but significant acknowledgement that her intellectual property was valued equally with her male colleagues.

But perhaps her most enduring impact is not in the record books but in the imaginations of young people who saw that a Black girl from West Virginia could help send astronauts to the stars. Katherine Johnson demonstrated that excellence and perseverance can overcome even the most unfair obstacles. A fun fact: she was known for her love of intricate puzzles and crosswords, which she completed in ink to show she never made mistakes. When she died in February 2020 at the age of 101, she had lived to see the world name NASA facilities, schools, and scholarships after her. Her life remains a powerful example that numbers, when combined with courage, can change the world and that sometimes the most important calculations are the ones that defy expectations.