February 11th is UNESCO’s International Day of Women and Girls in Science. As part of encouraging women and girls in science, technology, engineering and mathematics (STEM) fields, we highlight a few notable women who’ve made significant contributions to GNSS and satellite positioning: Gladys West, Claudia Alexander and Frances Northcutt.
Gladys West, the Mother of GPS
Without understanding Earth’s geometric shape, orientation in space and gravitational field, we wouldn’t be able to calculate locations and positions on Earth. The mathematical modelling that enabled the precise positioning upon which we all rely originated from Gladys West, an African American mathematician known as the “Mother of GPS.”
After graduating with a Bachelor of Science in Mathematics and later a Master of Mathematics, West was hired at the Naval Surface Warfare Center as a programmer in 1956, the second Black woman ever hired there. From the 1960s onwards, West was drawn to studying satellites and how they enabled modelling of things on Earth – she was the project manager for the Seasat radar altimetry project designing a satellite that could remotely sense oceans.
This interest grew in the ’70s and ’80s when she programmed an IBM computer to model Earth’s shape, including algorithms that took into account gravitational changes, tidal forces and more. It’s this modelling work that formed the base of the Global Positioning System. GPS launched in 1978, with West researching how to increase positioning accuracy throughout the ’80s. GPS became fully operational in 1993, and West retired in 1998 after 42 years working in satellite geodesy.
For most of the 20th century, West’s contributions to satellite positioning were relatively unknown until 2018. When her involvement with GPS was discovered, the BBC selected West as one of their 100 Women of 2018. She also won the award for “Female Alumna of the Year” from Virginia State University, where she had graduated in 1952. For her pioneering work in precise positioning technology, West was inducted into the Air Force Space and Missile Pioneers Hall of Fame in 2018, making her one of the most notable women in GNSS.
Claudia Alexander, understanding solar wind and planetary science
Geophysics is the underlying science in GNSS and satellite positioning. While geophysics investigates the Earth and the forces that act upon the planet, scientists can extrapolate these discoveries to understand what happens on other planets or objects in space. Claudia Alexander, a Canadian-born African American, used her geophysics and planetary science expertise in her work at NASA’s Jet Propulsion Laboratory.
Her masters’ thesis from the University of California, Los Angeles included studying the solar cycle variations in Venus’ ionosphere and how it interacted with solar wind. Alexander’s studies continued at the University of Michigan in her Ph.D. on the physics of space plasma. Her work expands our understanding of how the sun affects planets and their atmospheres, including Earth’s ionosphere.
While completing her degrees, Alexander continued working at NASA, becoming the Galileo Jupiter mission project manager during its final phase, discovering 21 new moons of Jupiter including identifying a thin ionosphere on the moon Ganymede. In addition to supervising the Galileo spacecraft’s decommission and dive into Jupiter’s atmosphere in 2003, Alexander led research on magnetospheres, space plasma, comets and the physics behind solar wind.
Her most recent contributions were developing NASA’s Deep Space Network, a communications network between NASA and space probes. The network enables a two-way delivery of data to unmanned spacecrafts for scientists to gather telemetry, track position and velocity of satellites, monitor Very Long Baseline Interferometry observations and more.
Alexander saw many accreditations for her work in geophysics and planetary science, including the Emerald Honor for Women of Color in Research & Engineering in 2003. She passed away in 2015 from breast cancer. To honour her legacy as one of many notable women in GNSS, the European Space Agency named a feature on the comet 67P/Churyumov-Gerasimenko after her during its Rosetta mission – notably, this was Alexander’s favourite comet.
Frances Northcutt at Orbital Control
GNSS positioning relies upon our understanding of orbits and our exploration of nearby space. A key figure in the scientific knowledge of orbits and nearby space is Frances Northcutt. Beginning her career as a human computer in 1965 with the aerospace company TRW Inc. with a mathematics degree from the University of Texas, Northcutt was contracted to support computing efforts in NASA’s Apollo program. Her mathematics skills were quickly recognized, and she was promoted to become a technical staff, NASA’s then-title for engineering roles.
At only 21 years old, Northcutt was the first woman to join NASA’s technical staff team and the first woman stationed in Mission Control. Her involvement was vital in the success of Apollo 8’s return to Earth. As the first crewed mission to orbit the Moon, Northcutt and her team’s fuel calculations were integral for a successful and accurate swing around the Moon back to Earth.
Northcutt demonstrated her expertise again during Apollo 13 and its challenging mission to return home after an oxygen tank exploded. With the necessary maneuvers computed and simulated, Northcutt and her team ensured the Apollo 13 crew returned home safely, earning those involved a Presidential Medal of Freedom Team Award for their work and placing Northcutt as one of the most notable women in GNSS history.
As one of the few women at TRW and NASA and one of the youngest, Northcutt pushed for improved pregnancy leave policies, affirmative action and other feminist efforts. She was active in the women’s liberation movement in the 60s and 70s, bringing policies and support for progressive legislation to the Houston city council. Her efforts were recognized when she was named the Women’s Advocate for the City in 1974 by the Houston mayor.
While science and engineering remain passions, Northcutt shifted her career endeavours to earn her law degree in 1984, practicing criminal law with an emphasis on civil rights. Her activism continued as a board member for the National Organization for Women, becoming president of the Texas NOW chapter in 2019.
Women at the forefront of innovation today
From lead engineers to product managers, women play a key role in scientific innovation and the development of GNSS technologies. Here is a small snapshot at some of the notable women currently making GNSS history at Hexagon | NovAtel and across the Hexagon Autonomy & Positioning division.
Jennifer Busser, Product Manager of Correction Services at NovAtel, graduated with a Bachelor of Science in Geomatics Engineering in 2018. She balances these technical skills with a passion for connecting people to the world of GNSS positioning, as seen in her Intro to GNSS episode on Reducing GNSS Errors.
After earning her Bachelor of Science in Geomatics Engineering in 2004, Sheena Dixon would join Hexagon | NovAtel and eventually become Hexagon’s Autonomy & Positioning division’s Segment Manager of New Markets. During that time, Dixon contributed to scientific innovations including Boeing’s Unmanned Little Bird (ULB) program in 2012, which involved testing and demonstrating a highly precise navigation system for vertical takeoff and landing of an unmanned aerial system on a marine vessel. This project was featured in the 2013 May/June issue of InsideGNSS, accessible here.
Sandy Kennedy, Hexagon’s Autonomy & Positioning division’s VP of Innovation, graduated with her Master of Science in Geomatics Engineering in 2002, focusing on integrating GPS and inertial navigation sensors. But her first patent did not have any inertial components: “Method for positioning using a GPS in a restrictive coverage environment” (US 7529770). You can read more about her early GNSS+INS work in the 2005 publication, “Integration of Inertial Measurements with GNSS – NovAtel SPAN Architecture” (S. Kennedy and J. Hamilton, in Proc. Symposium Gyro Technology, Stuttgart, Sept. 2005).
Graduating with a Master of Science in Geomatics Engineering specialization in position, navigation and location in 2016, Laura Norman works as a geomatics engineer in the safety critical systems department at Hexagon | NovAtel. With her current focus on GNSS integrity, she has played a key role in several publications and research projects, including this presentation on Integrity Performance for Precise Positioning in Automotive. Norman was elected as a technical representative on the Institute of Navigation’s 2021-2023 council.
Encouraging women and girls in STEM
Below are resources to continue supporting and encouraging women and girls to pursue scientific careers and interests.