Later this year, NASA will launch a mission dedicated to studying the geocorona—Earth’s extended hydrogen atmosphere that glows faintly in ultraviolet light. The spacecraft was named the Carruthers Geocorona Observatory in 2022 to honor an astrophysicist whose pioneering work fundamentally changed our understanding of ultraviolet astronomy and Earth’s atmospheric structure.

George Robert Carruthers earned this recognition through decades of groundbreaking research at the Naval Research Laboratory (NRL), where he developed revolutionary instruments for space-based ultraviolet observations. His most famous achievement was creating the far ultraviolet camera that Apollo 16 astronauts deployed on the lunar surface in 1972, providing humanity’s first clear view of the geocorona from space. Yet, despite his important contributions to space science, Carruthers remained an intensely private individual whose complete story has only now been told in full.

David DeVorkin, senior curator emeritus of the history of astronomy at the National Air and Space Museum, has written a definitive biography with From the Laboratory to the Moon: The Quiet Genius of George R. Carruthers, published earlier this year in both hard-copy and open-access formats by MIT Press. A renowned scholar, DeVorkin brings exceptional credentials to this project, and many of his oral histories are held by AIP’s Niels Bohr Library and Archives, including some of those conducted for this book.

DeVorkin’s archival research and extensive interviews reveal the full story of how an African American farm boy rose to become one of America’s most respected space scientists.

The making of a space scientist

Carruthers was born in 1939 in Cincinnati, Ohio, the eldest of four children, and his family moved to a farm when he was five or six years old. His early fascination with space began with reading science magazines and science fiction, and with a telescope kit his father helped him buy around age twelve, sparking a lifelong passion for understanding the cosmos. But this peaceful childhood was soon upended when his father died of a cerebral hemorrhage. His mother, Sophia, moved the family close to relatives in Chicago’s South Side, where she hoped to find better opportunities for her children’s education.

In Chicago, despite financial hardships, Sophia Carruthers encouraged her son’s scientific interests. George devoured science fiction and excelled in mathematics and physics at Englewood High School. A pivotal experience came through the Adler Planetarium’s telescope-making program, where George ground and polished his own 4¼-inch mirror and constructed a simple wooden reflector. As DeVorkin notes, the planetarium and its library represented an “order of magnitude jump” over anything Carruthers had previously experienced in science. His teachers recognized his exceptional talent, even when it got in the way of class. DeVorkin writes that “his parents got critical letters from teachers that he was drawing spaceships in class rather than doing his schoolwork.”

Carruthers earned his bachelor’s degree in aeronautical engineering from the University of Illinois in 1961, followed by a master’s degree in nuclear engineering in 1962. He completed his PhD in aeronautical and astronautical engineering in 1964, also at Illinois, writing his thesis on “the recombination of atomic nitrogen behind shocks in the Mach number range 2 to 10,” a subject related to Carruthers’s interest in rocketry and relevant to the US government’s interest in missiles.

On graduation, Carruthers joined NRL in Washington, DC, where he would remain until his retirement. The 1960s were an extraordinary time to enter space science, as NASA was pushing toward the Moon and new technologies were opening unprecedented opportunities for astronomical observation. At NRL, Carruthers found himself at the center of these developments, working on cutting-edge projects.

According to DeVorkin, Carruthers’s genius lay in his ability to design and build sophisticated instruments that could capture ultraviolet light from space—wavelengths that are largely absorbed by Earth’s atmosphere and thus mostly invisible to ground-based telescopes. His work was both highly technical and deeply creative, requiring him to solve complex engineering problems while pushing the boundaries of what was scientifically possible.

His breakthrough achievement came with the Far Ultraviolet Camera/Spectrograph, pictured above, an elegant instrument that he designed for the Apollo 16 mission. Weighing just 53 pounds, this gold-plated camera represented years of meticulous development and testing. When astronauts John Young and Charles Duke positioned it on the lunar surface in April 1972, it became the first astronomical observatory on another world.

The images Carruthers’s camera captured opened new frontiers in astronomy. For the first time, scientists could see Earth’s neutral hydrogen corona—the geocorona—extending far beyond our planet’s atmosphere. The instrument also photographed nebulae, star-forming regions, and other deep space objects in ultraviolet light, revealing details of the universe otherwise invisible from Earth.

But the Apollo 16 camera was just one highlight in a prolific career. Carruthers designed ultraviolet instruments for numerous space missions, including Skylab and various sounding rocket flights. He held multiple patents and authored dozens of scientific papers that advanced understanding of stellar evolution, interstellar matter, and galactic structure.

A “not-so-hidden figure”

Carruthers’s achievements were all the more remarkable given the racial barriers he faced throughout his career. As one of the few African American scientists in the space program during the 1960s and 1970s, he worked in an overwhelmingly white field, during the height of the civil rights movement. Yet those who knew him described a man who preferred to let his work speak for itself rather than engage in public advocacy or confrontation.

As Carruthers’s career progressed and his achievements brought him increasing visibility, he gradually embraced a more public role as an advocate for diversity in science and engineering. Understanding that representation mattered, he began visiting schools, participating in science fairs, and encouraging young people—particularly students of color—to pursue STEM careers.

DeVorkin places Carruthers’s story within the broader context of space history scholarship, noting that, as Margaret Weitekamp and other scholars have observed, early histories of spaceflight did not address “questions of race and ethnicity.” He explains that more recent efforts have worked to correct this gap, particularly through works like Margot Lee Shetterly’s Hidden Figures , which brought recognition to the critical but overlooked contributions of black women at NASA.

But, as DeVorkin points out, Carruthers’s story defies an easy fit in this narrative, with his own employer, NRL, dubbing him their “not-so-hidden figure,” celebrating not only his scientific achievements but also “his later efforts making his world accessible to young students.”

DeVorkin’s biography reveals how Carruthers navigated challenges with dignity and determination. His dedication to his work became the stuff of NRL folklore—colleagues told stories of finding him in the lab at all hours, completely absorbed in solving technical problems. One amusing anecdote captures this intensity: while preparing for a launch at the White Sands Missile Range in New Mexico, when a secretary told him it was five o’clock, “George looked up, bleary eyed, and said ‘AM or PM?’” having lost all track of time in his work.

This ability to focus served Carruthers well. His instruments consistently performed flawlessly in space, earning him respect throughout the scientific community. Awards and recognition followed, including election to prestigious scientific societies and numerous honors from NASA and other organizations. The National Medal for Technology and Innovation, presented by President Barack Obama in 2013, represented a pinnacle of recognition.

George Carruthers passed away in 2020 at age 81, leaving behind a remarkable legacy of scientific achievement and mentorship. DeVorkin’s biography ensures that Carruthers’s contributions will not be forgotten.

Rebecca Charbonneau
American Institute of Physics
rcharbonneau@aip.org

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