George Carruthers built his first telescope from a kit in 1949, when he was 10 and living in rural Ohio. Fascinated by space, he devoured magazine articles about space travel.
If the unknown was going to be explored, he wanted to be a part of it.
Two decades later, as an astrophysicist and engineer — one of the few at the time who were Black — he would design an advanced telescopic device that was used during the Apollo 16 mission in 1972 to produce ultraviolet photographs of the geocorona, Earth’s outermost atmosphere, as well as stars, nebulae and galaxies.
“In March 1610, Galileo Galilei reported the first use of a telescope to view mountains and maria on the moon,” Dr. Carruthers and Thornton Page, his collaborator on the project, wrote in a NASA report in late 1972. “On April 21, 1972, the Apollo 16 commander positioned a somewhat more complex optical instrument at the Earth from the moon and obtained several remarkable photographs showing atmospheric rather than surface features.”
Dr. Carruthers, who went on to design even more telescopes that flew aboard NASA spacecraft, died on Dec. 26 in a hospital in Washington. He was 81. His brother Gerald said the cause was congestive heart failure.
A slight, reserved man who often rode his bicycle to work, Dr. Carruthers started at the United States Naval Research Laboratory in 1964 and brought to it his fascination with telescopes.
In 1970, one of his telescopic creations, which had been sent into space on an unmanned rocket from the White Sands Missile Range in New Mexico, proved the existence of molecular hydrogen between stars and galaxies. Molecular hydrogen, which is vital to how stars are formed, had until then been notoriously difficult to detect.
By then, Dr. Carruthers was working on the Apollo mission and leading a team that built the lightweight, gold-plated Far Ultraviolet Camera/Spectrograph, which the astronauts John Young and Charles M. Duke Jr. would deploy on the Descartes Highlands.
On each of their moonwalks during their 71 hours on the moon, Mr. Young and Mr. Duke switched the telescopic device on. “Once the astronauts set it on an object, they could move away and work, then come back and change the direction of the camera,” the space historian David H. DeVorkin, senior curator of the National Air and Space Museum, said in a phone interview.
The device was left behind when the astronauts departed. “He was a great tool builder who applied himself to scientific questions,” said Mr. DeVorkin, who is writing a biography of Dr. Carruthers. “He didn’t come up with new questions, but he and his science were very practical.”
In 1973 Dr. Carruthers received the Helen B. Warner Prize from the American Astronomical Society as the year’s outstanding astronomer under 35. In 2013, President Barack Obama presented Dr. Carruthers with the National Medal of Technology and Innovation, the nation’s highest honor for technological achievement.
When Dr. Carruthers was honored by NASA during Black History Month in 2016, Charles F. Bolden Jr., the space agency’s administrator, said, “He has helped us look at our universe in a new way by his scientific work and has helped us as a nation see ourselves anew as well.”
George Richard Carruthers was born on Oct. 1, 1939, in Cincinnati. His father, also named George, was an engineer at Wright-Patterson Air Force Base, near Dayton, Ohio. His mother, Sophia (Singley) Carruthers, was a postal worker. The family moved northeast to Milford, a farming community, in the 1940s.
“When I was about 8 or 9 years old, I got a Buck Rogers comic book from my grandmother, and that was, of course, long before there was any such thing as a space program,” Dr. Carruthers said in an oral history interview with the American Institute of Physics in 1992. “Since it was science fiction, nobody took spaceflight seriously in those days, back in the late ’40s, early ’50s.”
His father died when he was 12, and his mother moved the family to Chicago, where George took telescope-building classes at the Adler Planetarium and found inspiration in articles about the future of space exploration in Collier’s magazine written by experts like the German-born master rocket builder Wernher von Braun, the science writer Willy Ley and the astronomer Fred Whipple.
Dr. Whipple’s suggestion that there could be advantages to astronomical work from space confirmed George’s interest.
“Most of the astronomers at the planetarium,” Dr. Carruthers said in the oral history interview, “thought that was nonsense, that astronomy is done with ground-based telescopes, and you shouldn’t waste your time thinking about going into space.”
In October 1957, during his first semester at the University of Illinois at Urbana-Champaign, the Soviet Union launched Sputnik, the first artificial earth satellite. He and other members of the school’s astronomy club watched Sputnik as it passed overhead. More important, Sputnik’s success legitimized Dr. Carruthers’s desire for a career in spaceflight engineering.
After graduating from the university in 1961 with a bachelor’s degree in aeronautical engineering, he continued at the school, receiving a master’s in nuclear engineering and a doctorate in aeronautical and astronautical engineering.
In his first eight years at the naval laboratory, his increasingly sophisticated telescopic devices flew on numerous unmanned rockets. One, in 1973, observed the Comet Kohoutek in from Skylab, the first United States space station; on another mission, a device of his unexpectedly captured a meteor disintegrating in Earth’s atmosphere; on still another, his handiwork was aboard the Spartan satellite that was released by the space shuttle Discovery in 1995 to seek the material from which new stars and planets form.
But his Apollo 16 telescope was his most significant achievement; he was at the Johnson Space Center in Houston during that mission.
“We could actually hear them talking about our instrument,” Dr. Carruthers told an interviewer for a space center oral history in 1999. Mr. Young, he recalled, “was using a sight on the side of the camera to point it at the Earth in order to set the reference for all of the other targets that we were going to be using, and he verified that he had sighted the Earth and it was in the center of his field of view.”
Dr. Carruthers retired from the naval laboratory in 2002.
In addition to his brother Gerald, he is survived by his wife, Debra (Thomas) Carruthers, and another brother, Anthony.
In retirement, Dr. Carruthers taught earth and space science at Howard University, where he had been involved since the 1990s as an evaluator for the school’s NASA-funded Center for the Study of Terrestrial and Extraterrestrial Atmospheres.
At night he took students to the school’s Locke Hall observatory to look at stars and planets from a telescope. He also helped high school students build telescopes in a summer outreach program at the university.
“He had a very reticent personality, and you’d have to draw him out to make him talk,” Prabhakar Misra, a professor of physics at Howard, said by phone. “But when he interacted with students — which was his passion — he became a different person.”