John Glenn, the first American to orbit the Earth and a former U.S. senator and war hero, has been hospitalized for more than a week, an official said on Wednesday.

Glenn, 95, is at the James Cancer Hospital at Ohio State University but does not necessarily have cancer, said Hank Wilson, spokesman at the university’s John Glenn College of Public Affairs, which Glenn helped found.

“When you’re 95, it’s always considered serious,” said Wilson, who did not have further details about Glenn’s condition or his prognosis.

Glenn, the last surviving member of the original seven “Right Stuff” Mercury astronauts, had a knee replacement operation in 2011 and underwent heart surgery in 2014.

Glenn was credited with reviving U.S. pride after the Soviet Union’s early domination of manned space exploration, as he became the first American to orbit the Earth on Feb. 20, 1962. Reaching speeds of more than 17,000 miles per hour, he circled the globe three times in just under five hours in the Friendship 7 capsule. Glenn instantly became a hero, receiving a ticker-tape parade in New York City and the Space Congressional Medal of Honor from President John Kennedy.

His experiences as a pioneer astronaut were chronicled in the book and movie “The Right Stuff,” along with the other Mercury pilots.

Glenn also became the oldest astronaut ever, returning to space at the age of 77 on Oct. 29, 1998.

Before he went into space, Glenn already had a reputation as one of the best test pilots in the country, setting a transcontinental speed record by flying from Los Angeles to New York in three hours and 23 minutes in July 1957. It was the first transcontinental flight to average supersonic speed.

He also earned six Distinguished Flying Crosses and flew more than 150 missions as a fighter pilot in World War Two and the Korean War.

Born in Cambridge, Ohio, Glenn served in the U.S. Senate as a moderate Democrat from Ohio from 1974 to 1999.

(Reporting by Kim Palmer; Writing by Ben Klayman; Editing by Matthew Lewis)

Hulton Archive via Getty Images 23rd January 1962: American astronaut John Glenn Jr smiles while wearing a spacesuit and helmet in front of the Mercury Atlas 6 spacecraft 'Friendship 7', Cape Canaveral, Florida. Glenn was launched on February 20, making him the first American in orbit.

Interim Archives via Getty Images Close-up of American astronaut John Glenn as he smiles while aboard the USS Randolph, after the completion of his Friendship 7 mission to orbit the earth, February 21, 1962.

MPI via Getty Images 1961: Astronaut John Herschell Glenn Jr, who became the first American to carry out a space orbit of the earth in the Project Mercury capsule Friendship 7.

Central Press via Getty Images 31st May 1966: John Herschel Glenn, the first American astronaut to orbit the earth, outside the Savoy Hotel during a lecture tour just beginning in Britain.

AFP via Getty Images US astronaut John Glenn poses, on January 20, 1962 during a training session before his 20 February 1962 NASA's Mercury program space flight aboard in the Mercury capsule Friendship 7 in which he became the first American to orbit the Earth.

ullstein bild via Getty Images John Glenn, 1960

ROBERTO SCHMIDT via Getty Images US astronaut and senator John Glenn waves as he leaves the Operations and Check out building at the Kennedy Space Center, FL, October 29th in route to board the US space shuttle Discovery.

Joe McNally via Getty Images Astronaut John Glenn poses for a photo with Discovery crew in October of 1998 in Houston, Texas.

Print Collector via Getty Images John H Glenn, American astronaut, May 1998.

Robert R. McElroy via Getty Images American politician and former astronaut Senator John Glenn gives a 'thumbs up' sign as he leans out of the door during his campaign for the Democratic Presidential nomination, Massachusetts, January 5, 1984.

John B. Carnett via Getty Images Former U.S. Senator John Glenn, the first American to orbit the Earth, could pave the way for civilians in space.