U.S. Sen. John Glenn, who was the first U.S. astronaut to orbit Earth and later spent 24 years representing Ohio in the Senate, has died at 95. He returned to space in 1998 at age 77.

WASHINGTON — He became a hero as the first American to orbit the Earth and then served as a longtime U.S. senator. But John Glenn, who died Thursday at age 95, continued to defy gravity decades after his initial flight.

The last survivor of the original Mercury 7 astronauts flew into space again at age 77. To his crewmates on the space shuttle Discovery in 1998, the legend-turned-senator had to be called John. Or else.

“He didn't want any special treatment as a U.S. Senator,” said crewmate Scott Parazynski. “He said, 'Don't call me Senator Glenn. I'm going to ignore you if you call me that. It's just John. Or it's payload specialist 2.'”

John Herschel Glenn Jr., who died at the James Cancer Hospital in Columbus, Ohio, had two major career paths that often intersected: flying and politics, and he soared in both of them.

Before he gained fame orbiting the world, he was a fighter pilot in two wars, and, as a test pilot, he set a transcontinental speed record. He later served 24 years in the Senate from Ohio. A rare setback was a failed 1984 run for the Democratic presidential nomination.

His long political career enabled him to return to space in the shuttle Discovery in 1998, a cosmic victory lap that he relished and turned into a teachable moment about growing old. He holds the record for the oldest person in space.

More than anything, Glenn was the ultimate and uniquely American space hero: a combat veteran with an easy smile, a strong marriage of 70 years and nerves of steel. Schools, a space center and an airport were named after him. So were children.

In 1957, the Soviet Union leaped ahead in space by putting the Sputnik 1 satellite in orbit, and then launched the first man in space, cosmonaut Yuri Gagarin, in a 108-minute orbital flight in 1961. After two suborbital flights by Alan Shepard Jr. and Gus Grissom, it was up to Glenn to be the first American to orbit the Earth.

“Godspeed, John Glenn,” fellow astronaut Scott Carpenter radioed just before Glenn thundered off a Cape Canaveral launch pad, now a National Historic Landmark, to a place America had never been. At the time of that Feb. 20, 1962, flight, Glenn was 40 years old.

During the four-hour, 55-minute flight, Glenn uttered a phrase that he would repeat frequently throughout life: “Zero G, and I feel fine.”

“It still seems so vivid to me,” Glenn said in 2012 on the 50th anniversary of the flight. “I still can sort of pseudo feel some of those same sensations I had back in those days during launch and all.”

Glenn's ride in the cramped Friendship 7 capsule had its scary moments. Sensors showed his heat shield was loose after three orbits, and Mission Control worried he might burn up during re-entry when temperatures reached 3,000 degrees. But the heat shield held.

Glenn returned to space in a flight in 1998 aboard the Discovery. He got to move around aboard the shuttle for far longer — nine days, compared with just under five hours in 1962 — as well as sleep and experiment with bubbles in weightlessness.

Flying with the Mercury legend “was like playing basketball with Michael Jordan or doing astrophysics with Albert Einstein,” his crewmate Parazynski recalled.

Glenn was born July 18, 1921, in Cambridge, Ohio, and grew up in New Concord, Ohio.

Glenn was married to his childhood sweetheart, Anna Margaret Castor, who he wed in 1943. They had two children, Carolyn and John David.