Biography of Emmett Chappelle, American Inventor

Emmett Chappelle

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Emmett Chappelle (born October 24, 1925) is an African-American scientist and inventor who worked for NASA for several decades. He is the recipient of 14 U.S. patents for inventions related to medicine, food science, and biochemistry. A member of the National Inventors Hall of Fame, Chappelle is one of the most distinguished African-American scientists and engineers of the 20th century.

Fast Facts: Emmett Chappelle

  • Known For: Chappelle is a scientist and inventor who received over a dozen patents while working for NASA; he devised ways for scientists to measure plant health and detect bacteria in outer space.
  • Born: October 24, 1925 in Phoenix, Arizona
  • Parents: Viola Chappelle and Isom Chappelle
  • Education: Phoenix College, University of California at Berkeley, University of Washington
  • Awards and Honors: National Inventors Hall of Fame
  • Spouse: Rose Mary Phillips
  • Children: Emmett William Jr., Carlotta, Deborah, and Mark

Early Life

Emmett Chappelle was born on October 24, 1925, in Phoenix, Arizona, to Viola White Chappelle and Isom Chappelle. His family farmed cotton and cows on a small farm. As a child, he enjoyed exploring the desert environment of Arizona and learning about nature.

Chappelle was drafted into the U.S. Army right after graduating from Phoenix Union Colored High School in 1942 and was assigned to the Army Specialized Training Program, where he was able to take some engineering courses. Chappelle was later reassigned to the all-Black 92nd Infantry Division and served in Italy. After returning to the United States, he went on to study electrical engineering and earn his associate's degree from Phoenix College. He then earned a B.S. in biology from the University of California at Berkeley.

After graduating, Chappelle went on to teach at the Meharry Medical College in Nashville, Tennessee, from 1950 to 1953, where he also conducted his own research. His work was soon recognized by the scientific community and he accepted an offer to study at the University of Washington, where he received his master's degree in biology in 1954. Chappelle continued his graduate studies at Stanford University, though he did not complete a Ph.D. degree. In 1958, Chappelle joined the Research Institute for Advanced Studies in Baltimore, Maryland, where his research on single-celled organisms and photosynthesis contributed to the creation of an oxygen supply system for astronauts. He went on to work for Hazelton Laboratories in 1963.

Innovations at NASA

In 1966, Chappelle began working at NASA's Goddard Space Flight Center in Greenbelt, Maryland. His work as a research chemist supported NASA's manned space flight initiatives. Chappelle pioneered a way to develop the ingredients ubiquitous in all cellular material. Later, he developed techniques that are still widely used for the detection of bacteria in urine, blood, spinal fluids, drinking water, and foods. Chappelle's research helped NASA scientists develop a way to remove soil from Mars as part of the Viking program.

In 1977, Chappelle turned his research efforts toward the remote measurement of vegetation health through laser-induced fluorescence (LIF). Working with scientists at the Beltsville Agricultural Research Center, he advanced the development of LIF as a sensitive means of detecting plant stress.

Chappelle was the first person to identify the chemical composition of bioluminescence (the emission of light by living organisms). Through his studies of this phenomenon, he proved that the number of bacteria in water can be measured by the amount of light given off by that bacteria. He also showed how satellites can measure luminescence levels to monitor the health of crops (growth rates, water conditions, and harvest timing) and enhance food production. Chappelle used two chemicals produced by fireflies—luciferase and luciferin—to develop a technique for detecting adenosine triphosphate (ATP), an organic compound found in all living organisms:

"You start out with the fire fly which you have to obtain by the way. Either you catch it yourself or you pay the little kids to run around catching them for you. Then you bring them into the lab. You chop off their tails, grind them up and get a solution out of these ground-up tails...You add adenosine triphosphate to that mixture and you get light."

Chappelle's method for identifying ATP is unique in that it works outside of earth's atmosphere—meaning it could, in theory, be used to identify extraterrestrial life. The field of exobiology—the study of life beyond the planet Earth—owes much to Chappelle's work. The scientist himself, in an interview with The HistoryMakers, said he is inclined to believe there is life beyond Earth: "I think it's likely. It's not life as we know it here on Earth. But I think it's likely that there's, there are organisms up there that reproduce."

Chappelle retired from NASA in 2001 to live with his daughter and son-in-law in Baltimore, Maryland. Along with his 14 U.S. patents, he has produced more than 35 peer-reviewed scientific or technical publications and nearly 50 conference papers. He has co-authored and edited numerous other publications on a variety of subjects.


Chappelle earned an Exceptional Scientific Achievement Medal from NASA for his work. He is a member of the American Chemical Society, the American Society of Biochemistry and Molecular Biology, the American Society of Photobiology, the American Society of Microbiology, and the American Society of Black Chemists. Throughout his career, he has mentored talented minority high school and college students in his laboratories. In 2007, Chappelle was inducted into the National Inventors Hall of Fame for his work on bioluminescence. He is often included on lists of the most important scientists of the 20th century.


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Bellis, Mary. "Biography of Emmett Chappelle, American Inventor." ThoughtCo, Feb. 16, 2021, Bellis, Mary. (2021, February 16). Biography of Emmett Chappelle, American Inventor. Retrieved from Bellis, Mary. "Biography of Emmett Chappelle, American Inventor." ThoughtCo. (accessed June 5, 2023).