Woman of the Day mathematician and aerospace engineer Mary Jackson born OTD 1921 in Virginia, the first black woman engineer at NASA and a real trailblazer. Mary’s aptitude for STEM subjects became apparent at an early age. She graduated from high school with honours and earned her degrees in physical science and mathematics at the age of 21. After graduation, she taught maths for a year at a segregated school in Maryland. At that time, segregation was firmly established and it ruled and restricted Mary’s opportunities in work and in life in a way that seems incomprehensible today, or should. In 1951, Mary became a research mathematician, a “human computer” at the National Advisory Committee for Aeronautics (NACA) in Langley, Virginia (the predecessor to NASA) and in 1953, she moved to the Compressibility Research Division of NACA, home of the first wind tunnel. The women provided data later essential to the early success of the US space programme. Compressibility is the property of air that allows it to change its density and pressure when it is subjected to a force or a change in speed. It is a major issue as aircraft approach Mach 1 because when the air around your aircraft moves faster than the speed of sound, it can’t adjust to the shape of your aircraft, and it forms shock waves. At work, segregation continued to rule Mary’s life. President Franklin D. Roosevelt had signed Executive Order 8802 prohibited discrimination in the defence industry in 1941. The federal courts had ruled segregation unlawful everywhere in the USA in 1956, but desegregation did not begin in Virginia until early 1959 and Virginia state law still enforced segregation in the workplace: separate restrooms and cafeterias designated “white” or “colored.” In the NACA cafeteria, white people could choose their meals and sit in a dining room. Black people had to ask a cafeteria worker for what they wanted and take their food back to their desks. After months of unequal treatment, Mary had had enough and thought about resigning but an intervention by a supervisor changed her mind. He saw her potential as a future engineer and invited her to work for him while she took engineering classes. Since Virginia’s schools were still segregated, she had to obtain special permission to take classes with white students. "Every time we get a chance to get ahead, they move the finish line." In 1958, Mary was promoted to aeronautical engineer in 1958 soon after NASA took over from NACA and became NASA's first black female engineer, specialising in wind tunnel and real-world aircraft flight experiments. Her goal was to understand air flow including thrust and drag forces in order to improve American planes. Despite further early promotions, Mary was denied management-level positions so in 1979, she took a demotion to become manager of the women’s programme at NASA to improve opportunities for all women at NASA. Setting a classic example of “If you can see it, you can be it”, this expert on wind tunnels helped African American children in her community in the 1970s to create a miniature wind tunnel for testing airplanes. "We have to do something like this to get them interested in science. Sometimes they are not aware of the number of black scientists, and don't even know of the career opportunities until it is too late." This remarkable woman died in 2005 at the age of 83. Sixteen years later, NASA’s HQ in Washington DC was renamed the Mary W. Jackson NASA Headquarters.