103-year-old J. Cary Nettles of Columbia, Tennessee, helped put Buzz Aldrin and Neil Armstrong on the moon.

Apollo 11 Launch
Credit: Ralph Crane/Getty Images

These days, J. Cary Nettles spends his time tinkering around his house in Columbia, Tennessee. The 103-year-old divides his waking hours between rebuilding steamer train engines in his basement, talking on HAM radio, and watching his beloved Atlanta Braves.

Nettles, believed to be the nation's oldest living rocket scientist, didn't always lead such a run-of-the-mill life. During his tenure at NASA, the now-white haired Louisiana native helped save the U.S. space program that put a man on the moon 50 years ago.

Back in 1961, when President John F. Kennedy announced his intent to win the race to land astronauts on the moon, the U.S. has a serious problem. As The Tennessean reports, the country's test rockets were either blowing up on the launch pad or shortly after liftoff.

At the time, Nettles ran the country's largest supersonic wind tunnel in Ohio, where NASA (then the National Advisory Committee for Aeronautics) experimented with the effects of high speeds on jets and rockets. Nettles and his team discovered that after the rockets were launched, hot exhaust was turning back into the rocket and destroying them. Their solution? An exhaust pipe on the bottom of the rocket like the ones on cars.

"The next day, I was the country's leading authority on rocket-based aerodynamics," Nettles told The Tennessean.

"We put a stove pipe on it," he explained. "Since I put the correction adaptation on the Atlas rocket, it has not failed from that source anymore."

NASA gave Nettles and his colleague Ed Jonash the Distinguished Service Medal in 1966—the same medal the astronauts got.

Nettles' solution ultimately helped the U.S. win the space race, beating the Soviets and getting man on the moon—two men in fact. On July 20, 1969, Neil Armstrong followed by Buzz Aldrin stepped off of Apollo 11 and onto the surface of the moon. Nettles watched it all on television.

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The next year, Nettles retired from NASA at 55 years old. He and his wife Marabel moved to a National Park in Arkansas.

"I had enough," he recalled to The Tennessean. "The excitement was too much."