West's work on modeling the Earth's shape assisted with the development of GPS, today used by an estimated 4 billion people.

Gladys West, GPS pioneer and one of NASA's famed 'Hidden Figures,' dies at 95

Source: space
Source Link: https://www.space.com/space-exploration/gladys-west-gps-pioneer-and-one-of-nasas-famed-hidden-figures-dies-at-95