Gladys West
Born in the town of Sutherland, a rural area of Virginia, under the name Gladys Mae Brown, she understood very early on that education was the only way to escape years of hard work in the fields.
From childhood she was an outstanding student and earned a full scholarship to study mathematics at Virginia State College (now Virginia State University), where she graduated at the top of her class.
1950s America wasn't a friendly environment for an African American woman to pursue science. Even so, West continued her studies and earned a master's degree in mathematics at Virginia State University, the same institution where she had done her undergraduate degree. Decades later, well into her scientific career, she would also complete a doctorate at Virginia Tech.
Her first job was as a math teacher, and it was in that context that a colleague told her about an opening for a mathematician programmer at a U.S. Navy research center, specifically the Naval Proving Ground in Dahlgren, Virginia, known today as the Naval Surface Warfare Center Dahlgren Division.
There, West began working with some of the most advanced scientific computers of the time. One of her first projects involved participating in a study on the orbital relationship between Pluto and Neptune, a problem that required millions of calculations to accurately model their trajectories. This kind of work helped her build expertise in scientific computing and numerical analysis, skills that would later prove key to her research with satellite data.
The True Shape of the Earth and the Cold War
During the 1950s and 60s, the United States and Russia were in the middle of the Cold War. The fight for scientific, technological, military and space dominance was at its peak. One of the challenges at the time was precise navigation of the Earth. Back then, measurements of geographic positions could be off by several kilometers, which was a very critical problem when evaluating strategy in this demanding Cold War.
The central problem was that, at the time, we didn't know the exact shape of the Earth, which looks like a sphere at first glance, but technically isn't: it's a GEOID. It's slightly flattened at the poles, wider at the equator, and also has irregularities caused by variations in gravity, mass distribution, mountains, oceans and the density of materials beneath the surface.
West and her team worked analyzing large datasets from geodetic satellites. One of the most important was GEOS-3, launched in the 1970s to study Earth's gravitational field and measure ocean height using radar altimetry. The satellite sent information about variations in the gravitational field, ocean surface measurements, orbital data and altimetry observations. The scientific challenge was integrating all that data into a coherent mathematical model of the Earth.
Keep in mind that this work was done at a time when computers took up entire rooms and had limited resources, so every calculation had to be designed in detail. First, the satellite data needed to be processed and corrected to eliminate errors. Then Earth's gravitational field was modeled using spherical harmonics, a mathematical technique for describing complex functions on the surface of a sphere. Those calculations were used to build geodetic models that related satellite positions to precise coordinates on the planet's surface. With each iteration, those models reduced errors and improved precision. These advances would prove fundamental to satellite navigation systems.
The Global Positioning System calculates positions by measuring how long it takes signals from several satellites to arrive; with at least four signals it's possible to determine latitude, longitude, altitude and correct the receiver's clock. But these calculations only work correctly if the mathematical model of the Earth is accurate. West's work contributed precisely to refining those models, increasing the precision of the positioning systems used today by millions of devices.