When Valerie Thomas, in the late 1970s, invented the illusion transmitter— a type of 3D display technology— she was also a leader of the National Aeronautics and Space Administration's (NASA) Landsat Earth imaging program. From a little girl in the US state of Maryland, she had defied the odds to become a scientist and computer-science innovator whose work helped shape one of the most successful and versatile satellite imaging programs that continues today.
Thomas' patented illusion transmitter, which can reproduce an image at a remote site using a camera and parabolic mirrors, is also still in use at NASA, and has had applications in television technology as well as imaging for surgical procedures.
These accomplishments are but highlights in the distinguished career Thomas began in 1964 as a recent college graduate—and one of the few Black women who worked at the agency. No stranger to adversity, in a 2019 NASA oral-history interview, she described how in those early days she had "not seen a computer except in science fiction movies."
Thomas was born in Maryland in February 1943. From an early age, she developed an interest in mechanics after watching her father at work repairing televisions, she said in a CTV News interview. Seeing the inner workings of a television, with all its wires and circuits, fascinated her. She wanted to know how everything worked together to produce an image on the screen. This was, in fact, her introduction to the world of optics where she would find success.
Being Black and female in mid-20th century America, however, Thomas' path was far from ordained. She told Oprah Daily about how her curiosity for electronics began. At age eight, Thomas visited her local library and came across a book titled The Boy's First Book on Electronics. Excitedly, she took the book home to show her father hoping they could work on the science projects within. Her enthusiasm was not reciprocated, and she returned the book never having started on any of its projects. The book's discriminatory title and the lack of encouragement at home sent a clear message. Electronics were not for girls.
As time passed, Thomas' career in science seemed even less likely. She attended an all-girls school that hardly taught science and mathematics. Instead, she was encouraged to learn sewing and hairdressing, as these were seen as more fitting skills for girls in the 1950s.
However, Thomas was not to be deterred from her passion for electronics. She enrolled at Morgan State University, a public historically Black research university, as a physics major—one of two women in her class. She excelled academically and was set on a path to being hired as a data analyst at NASA just two weeks after her college graduation. That path would lead to Landsat.
Originally titled the Earth Resources Technology Satellite when it began in 1970, Landsat is the longest-running satellite program at NASA. Operated jointly with the US Geological Survey, Landsat satellites capture images of Earth across multiple wavelengths, allowing researchers to track a multitude of changing conditions on the Earth's surface and in its atmosphere. "It was very exciting because it was the first time that multispectral images of the Earth were produced from satellite data," Thomas said in the NASA interview.
Landsat images are free to the public, and program data is used across many different industries from agriculture to urban planning. And that is thanks to Thomas' early development of Landsat digital media formatting.
As she described in the NASA interview, when Landsat first became operational, Thomas saw researchers were having difficulty trying to access the complex digital data stored on computer-compatible tapes. So, she tried to configure the data in a more accessible way.
"The scientists had difficulty in understanding how the digital data on the tape matched the visual images represented on the hardcopy or computer screen. I had experience in decommutation of scientific data and printing the information in an easily understandable format."
Thomas became the go-to person to consult on Landsat data. The program continues to provide useful data about Earth's surface and atmosphere, making it one of NASA's most important resources. In fact, Landsat 9 launched 27 September 2021 with the expectation that its data would be available by this issue of Photonics Focus.
In 1976, Thomas attended a scientific exhibition where she experienced a lightbulb moment that would lead to another career breakthrough. One of the exhibits featured a projection of a burning light bulb that looked extremely real. When Thomas examined the actual light bulb being projected, it was not only turned off, but unscrewed from the lamp. She wondered how this was possible.
In a 2021 interview with Revolt TV, she said, "When I tried to touch it, my finger went right through what appeared to be a bulb. That caused my mind to wonder, what is going on? How did that happen? I decided to go to the library to look for a book to explain that phenomenon."
The trick? Concave mirrors being used to make a projection. Thomas was fascinated and wondered how she could develop this idea further. Her big breakthrough came the following year with her invention of the illusion transmitter. The device she invented, patented in 1980, expands on television technology. That is, it takes an image created with flat mirrors behind a TV screen and, using concave mirrors, turns them into 3D projections.
Thomas believed that visualizing moving images in this way would be far more interesting and realistic. Although 3D displays were not new, the difference with Thomas' invention was that it did not require special glasses to see the projected images. Hers is one among a small percentage of patents owned by Black inventors; even fewer are owned by Black women.
And though the technology is used by NASA, Thomas' illusion transmitter was developed on her own time, as her career soared at the space agency.
After success with Landsat, for example, she was asked to lead a team of some 50 scientists for the Large Area Crop Inventory Experiment (LACIE), which used Landsat data to predict wheat yields on a global scale. Completed in just five months, it demonstrates the vast capabilities of Landsat to address global issues like agriculture.
From LACIE, Thomas worked her way up to become the associate chief of Space Data Operations at NASA. During the rest of Thomas' three-decade career at NASA, she was put in charge of managing more projects such as the Space Physics Analysis Network. The project improved connectivity between computer systems and became a key part of the early internet. Thomas also developed the Minority University-Space Interdisciplinary Network which enables minority students at different institutions to connect and work with NASA scientists.
Since retiring from NASA in 1995, Thomas has used her platform and success to inspire others, especially women and young Black students. She works with organizations like the National Technical Association, Science Mathematics Aerospace Research and Technology, Inc., Shades of Blue, and Women in Science and Engineering. Thomas, who received her masters and doctoral degree while working at NASA is now a substitute teacher at a high school in Baltimore where she inspires young students to develop their passion for science.
Vanessa Emeka-Okafor is a doctoral student and Bell Burnell Scholar, Astronomy and Astrophysics Group, University of Warwick, UK.