Former Ohio Sen. John Glenn, best known for his exploits as an astronaut in the 1960s, has been hospitalized.

Glenn’s health has declined in recent years, and the last surviving member of NASA’s Project Mercury was losing his eyesight, and had undergone open heart surgery in 2014, Cleveland.com reported.

Glenn, 95, has been at The James Cancer Hospital at Ohio State University since last week.

NASA selected Glenn for its Project Mercury program in the late 1950s, after he had flown combat missions in World War II and the Korean War.

Once back stateside, Glenn joined Scott Carpenter, Gordon Cooper, Gus Grissom,Wally Schirra, Alan Shepard and Deke Slayton to form the Mercury Seven, a moniker that still oozes space-race nostalgia and was captured in the novel and film “The Right Stuff.” 

He wasn’t the first in space, but in 1962, he became the first American to orbit the earth.

Following his retirement from NASA, the Ohio native served four terms in the Senate and ran for president briefly in 1984, losing the nomination to Walter Mondale in the Democratic primaries. 

Glenn was the chairman of the Committee on Governmental Affairs, and sat on the Foreign Relations and Armed Services committees. In 1978, President Jimmy Carter awarded him the Congressional Space Medal of Honor.

After retiring from government, Glenn and his wife Annie moved to Columbus, Ohio, where he had helped establish Ohio State’s Institute of Public Service and Public Policy, now the John Glenn College of Public Affairs. 

Buckeye State lawmakers have expressed concern over Glenn’s hospitalization.

Ohio senior Sen. Sherrod Brown released a statement Wednesday after hearing the news.

“Connie and I ask Ohioans to join us in sending our love to John and Annie Glenn and their children,” Brown said, “and to respect their family’s privacy at this difficult time.”

Brown’s Republican colleague Sen. Rob Portman tweeted a similar show of support, writing “Jane and I send our thoughts and prayers on a speedy recovery to our dear friend John Glenn.”