Emmett Chappelle: Illuminating Paths Forward

There is nothing quite like the sight of a firefly to spark curiosity and motivate us to investigate our world. As you enjoy watching fireflies dot the landscape with twinkling lights on warm summer nights, it’s the perfect opportunity to explore the science behind this phenomenon and discover the inspiring inventors who have led the way toward understanding and harnessing the power of bioluminescence, or light emission from living organisms.

One of these innovative role models is National Inventors Hall of Fame^® Inductee Emmett Chappelle. Among the most impactful scientists of the 20th century, he not only studied fireflies and used the chemicals they produce to detect signs of cellular life, but he also made a variety of discoveries that have transformed scientific fields including biochemistry, space exploration, medicine and food science. Read on to learn more about how Chappelle changed the world.

From Buffalo Soldier to Biochemist

Chappelle was born in Phoenix, Arizona, in 1925. At the time, Phoenix was a largely agricultural city, and Chappelle was born into a farming family. He attended a segregated, single-room primary school followed by an all-Black public high school, where he graduated at the top of his class in 1942.

After graduating, Chappelle was drafted into the U.S. Army and assigned to the Army Specialized Training Program, and he was able to take a few engineering courses and pursue more advanced training.

Chappelle served in the 92nd Infantry Division, known as the “Buffalo Soldiers” — the only Black infantry unit that saw combat in Europe during World War II. In a 2014 letter he wrote to Ivan J. Houston, author of “Black Warriors: The Buffalo Soldiers of World War II,” Chappelle stated:

“My work is described on the internet. But so much of who I became — and who I am now — was determined by my years as a Buffalo soldier. Ivan, a great deal of African American experience is unknown, unrecorded and lost. History is, after all, written by the victors. Black Warriors is a contribution of great value to revealing the truth...[it] has brought me more joy than I can say.”

Chappelle spent four years in the Army and was wounded twice. Following his service, he returned to the U.S. and continued his studies. He completed his bachelor’s degree in biology in 1950 at the University of California, Berkeley, and taught biochemistry at Meharry Medical College in Nashville until 1953. While teaching, Chappelle conducted his own research in the field, leading him to complete his master’s degree in biochemistry one year later at the University of Washington.

Making Vital Discoveries

In 1958, Chappelle began working at the Research Institute for Advanced Studies in Baltimore, followed by Hazelton Laboratories in 1963 and the NASA Goddard Space Flight Center in 1966.

During his time at Hazelton and NASA, Chappelle pioneered a great deal of research in the field of bioluminescence. He discovered that all living cells are capable of bioluminescence in the presence of the same chemical combination found in fireflies.

Following this discovery, Chappelle developed a process to test for cellular life that involved combining two chemicals produced by fireflies: luciferin and luciferase. When combined, these chemicals will produce light as long as the chemical adenosine triphosphate (ATP) is present. ATP essentially provides chemical energy for cells to function and is therefore found in all living organisms.

Chappelle’s illuminating work became the building block for many important innovations. For instance, he worked alongside fellow biochemist Grace Picciolo to develop a system for NASA’s Viking lander to discover if life could exist on other planets. Chappelle and Picciolo’s system involved the lander collecting a small amount of planetary soil, grinding it into dust and adding the same bioluminescent chemicals used in his firefly tests. If the soil glowed, a photometer would measure it and the light would be proof that cellular life could exist outside Earth.

Beyond this breakthrough, Chappelle also used his inventive skills to prove that the number of bacteria in water could be measured by the amount of light emitted from that bacteria, allowing medical tests to detect infections in blood and urine. He also developed a way for satellites to measure luminescence levels to monitor the health of crops and help enhance food production. No matter the task, Chappelle found a way to use his skill set to help make improvements in many arenas.

Inspiring the Future

Chappelle retired from NASA in 2001, after 34 years at Goddard. He had earned 14 U.S. patents and NASA’s Exceptional Scientific Achievement Medal for his work. Throughout his career, he also mentored high school and college students from marginalized and underprivileged communities.

A 1995 edition of U.S. Black Engineer and Information Technology Magazine described Chappelle in this way:

“Even with such technical ability, his greatest asset is his personality. His laboratory is always buzzing with students working alongside him. Chappelle wears his prestige like casual clothing, never letting it interfere with how he relates to people. These characteristics may seem unlikely for a great scientist, but for Chappelle’s peers, acquaintances and the students for whom he is a mentor, he simply is the world-renowned Emmett Chappelle.”

In 2020, the Society for Research on Biological Rhythms (SRBR) announced that the Trainee and Young Faculty Diversity Enhancement fellowships would be renamed the Emmett Chappelle Awards. These awards are intended to promote the participation of underrepresented attendees at the SRBR meeting, and provide awardees with tools and opportunities to help them become the next leaders who could make illuminating discoveries.

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