Katherine Johnson, the stereotype-shattering mathematician whose calculations helped sling NASA astronauts into space, died February 24 at age 101.

“Katherine G. Johnson refused to be limited by society’s expectations of her gender and race while expanding the boundaries of humanity’s reach,” Barack Obama said when he awarded Johnson the Presidential Medal of Freedom in 2015.

For decades, Johnson, an African-American woman, was among NASA’s largely uncelebrated pioneers. Her exquisite facility with analytic geometry formed the foundation for NASA’s most daring space missions of the 1960s, including the first crewed flights to the moon. But like the other black women who worked for NASA at the time, Johnson remained mostly unknown outside of the space agency—until 2016, when Margot Lee Shetterly