John H. Glenn Jr., 95, whose 1962 flight as the first U.S. astronaut to orbit the Earth made him an all-American hero and propelled him to a long career in the U.S. Senate, died Thursday, the last survivor of the original Mercury 7 astronauts.

Sen. Glenn died at the James Cancer Hospital in Columbus, Ohio, where he had been hospitalized for more than a week, said Hank Wilson, communications director for the John Glenn School of Public Affairs of Ohio State University.

To the world, Sen. Glenn was an almost mythic American who placed an exclamation point on his space career with his triumphant return aboard the shuttle Discovery in October 1998. At 77, he became the world's oldest astronaut, back in the heavens after a 36-year hiatus.

Tributes poured in Thursday for the former astronaut and senator. Politicians, astronauts, educators and others repeatedly called him a hero, with many mentioning the phrase that first sent him into orbit:

"Godspeed, John Glenn."

  CHARLES DHARAPAK / AP
On May 29, 2012, President Obama awarded the Medal of Freedom to John Glenn, former astronaut and senator.

"When John Glenn blasted off from Cape Canaveral atop an Atlas rocket in 1962, he lifted the hopes of a nation. And when his Friendship 7 spacecraft splashed down a few hours later, the first American to orbit the Earth reminded us that with courage and a spirit of discovery there's no limit to the heights we can reach together," President Obama said. "The last of America's first astronauts has left us, but propelled by their example we know that our future here on Earth compels us to keep reaching for the heavens. On behalf of a grateful nation, Godspeed, John Glenn."

Duty, sacrifice, and valor

John Herschel Glenn Jr. was born on July 18, 1921, in Cambridge, Ohio, and grew up in nearby New Concord, then a town of about 1,000. His father owned a plumbing-and-heating business and his mother, Clara, taught elementary school.

Both parents were devout Presbyterians who instilled a strong religious spirit in their son, typical in the bustling, business-oriented community, a "dry" town that banned the sale of alcohol. In that atmosphere of faith and free market, Sen. Glenn grew up believing in principles of duty, sacrifice, and valor.

As a child, the boy known to his friends as "Bud" loved planes and the idea of flight, spending hours collecting models and attending air shows. At age 3, he met a 4-year-old girl named Anna Margaret Castor, whom everyone called "Annie." They became playmates and in the eighth grade started going steady. On April 6, 1943, they married, later becoming parents of two children, David and Carolyn.

From his youth, Sen. Glenn's success and prominence seemed almost preordained.

He was an honor student in high school, president of the junior class, and lead actor in the senior play. He lettered in football, basketball, and tennis even though he was not a particularly good athlete. After graduation, Sen. Glenn and his future wife enrolled at nearby Muskingum College, beginning classes in 1939.

Thrilled with flying

When Nazi Germany invaded surrounding countries that year, Sen. Glenn volunteered for civilian-pilot training at the airport in New Philadelphia, Ohio.

His parents were disappointed, hoping he would eventually take over his father's plumbing business. They worried about his fascination with such a dangerous pursuit as flying and feared he would eventually be sent into combat. Sen. Glenn, however, was thrilled with flying - receiving his pilot's license on July 1, 1941, five months before Pearl Harbor plunged America into World War II.

Sen. Glenn joined the Marines, who eventually sent him to Hawaii and into the war, where he flew 59 combat missions in the South Pacific. He decided to make his career in military service. In 1953, Sen. Glenn saw combat again during the Korean War, flying 63 missions. He shot down an enemy MiG during his first day in his F86 Sabrejet and two more in the next eight days, earning the nickname of the "MiG Mad Marine."

Sen. Glenn always was ambitious, a near-fanatical climber of the Marine Corps ladder. When the Korean War ended in July 1953, he enrolled at the Test Pilot School at the Naval Air Test Center in Maryland.

In 1956, he was assigned to the fighter-design branch at the Navy Bureau of Aeronautics, spending the next three years as a test pilot. In that capacity, Sen. Glenn set the transcontinental speed record in July 1957, the first pilot to make a coast-to-coast flight faster than the speed of sound.

Yet even bigger challenges beckoned.

In April 1959, Sen. Glenn was chosen as one of the original seven Mercury astronauts - the step that would rocket him to worldwide fame.

The seven brush-cut pilots were all super-achieving, ultracompetitive fliers, each determined to be the first man in space. Sen. Glenn, at ease with the art of self-promotion, did all he could to stand out from the others. During the astronauts' first news conference, he recited a mom-and-apple-pie line to the press. When a reporter asked who among them believed they would safely return to Earth, six astronauts raised one hand; Sen. Glenn raised two.

Still, Sen. Glenn was stunned when Alan B. Shepard Jr. was chosen for the first Mercury flight, leading America in the space race against the Soviet Union. Yuri Gagarin had become the first man in space on April 12, 1961, and Shepard followed scarcely a month later on May 5. The Russians won round two as well, sending Gherman Titov into a full day of orbits in August 1961. The United States quickly announced that Sen. Glenn would become the first American in orbit, a feat unlike any that had come before in this country.

It wasn't simply that space flight was new and perilous. Americans, watching on their black-and-white television sets, had become uncomfortably accustomed to the sight of test rockets blowing up on the launching pad, disintegrating in balls of fire and smoke.

"It's difficult to remember now how impossibly dangerous space flight seemed," the newsman Walter Cronkite wrote in Newsweek as Sen. Glenn prepared for his 1998 flight. "The stakes couldn't have been higher, nor the risks greater: We were in a cold-war space race, we thought then, for control of the very heavens."

'Oh, that view is tremendous'

On Feb. 20, 1962, Sen. Glenn lifted off from Cape Canaveral, his Friendship 7 capsule boosted skyward by a Mercury-Atlas rocket. He was 40, the oldest of the seven astronauts.

"Oh, that view is tremendous!" Sen. Glenn exulted as he sped along, 100 miles above the Earth, cruising at 17,500 mph.

He flew over a vastly different America, one that today seems young and naive today, a country without ZIP codes or Beatles albums, where John F. Kennedy was president and his brother Bobby was the attorney general. It was an era when Americans felt more secure about their lives and their destiny, bravery was in vogue, military service had not been tainted by Vietnam, and politics was unsullied by Watergate.

NASA
A camera on board the Friendship 7 spacecraft photographs astronaut John Glenn during his historic flight on Feb. 20, 1962.

The flight that made Sen. Glenn internationally famous nearly ended in catastrophe. The automatic controls failed, and Sen. Glenn had to manually maneuver the capsule down after three orbits. His ship reentered the atmosphere white-hot, the mission-control operators unsure whether the heat shield was coming loose. Sen. Glenn and his machine were in danger of being incinerated.

In the 1983 movie The Right Stuff, based on Tom Wolfe's best-selling history of the 1960s space effort, Sen. Glenn (played by Ed Harris) is depicted as humming "The Battle Hymn of the Republic" as his craft plummeted toward Earth. That was untrue, though there's no question Sen. Glenn faced the crisis with right-stuff composure.

His five-hour flight ended successfully when he splashed down in the Atlantic Ocean.

 VINCENT P. CONNOLLY / AP
Astronaut John Glenn and President John F. Kennedy inspect the Friendship 7, the Mercury capsule that Glenn rode into orbit. Kennedy presented a Distinguished Service medal to Glenn at Cape Canaveral, Fla., on Feb. 23, 1962.  In the background is Vice President Lyndon Johnson.

The nation rejoiced, with Sen. Glenn ushered to the White House and feted in ticker-tape parades - with real ticker-tape. Muskingum, which had withheld Sen. Glenn's degree over a residency dispute, was moved to grant him his bachelor of science in engineering. Sen. Glenn was so bright a national star that President Kennedy wouldn't risk putting him on another flight.

Launching a political career

Sen. Glenn became friends with Kennedy, and soon decided to launch his own political career. But his 1964 run for the Senate was aborted by a bad fall in the bathtub, which left him with a concussion and inner ear injury, and unable to campaign.

He retired from the Marines as a colonel in 1965, taking a job as vice president of Royal Crown Cola and then becoming president of Royal Crown International. He ran for the Senate in 1970, losing in the Democratic primary, and ran again in 1974. That time, Sen. Glenn won the nomination and the seat, claiming 65 percent of the vote to defeat Ralph Perk, the Republican mayor of Cleveland.

TANNEN MURRAY / AP
Sen. John Glenn (D., Ohio), with his wife, Annie Glenn, campaigns for president on Jan. 18, 1984, in Jackson, Miss.

In 1980, he was reelected by the largest margin in Ohio history. Three years later, Sen. Glenn sought the land's highest office, announcing his candidacy for president. His campaign for the Democratic nomination began with great hope but never took off, lanced by his wooden campaign appearances and bland speaking style.

"I admit to being dull," Sen. Glenn joked at the time. "But I'm not boring."

He dropped out of the race in March 1984. The eventual Democratic nominee, Walter F. Mondale, lost the presidential election to incumbent Ronald Reagan.

All-American image tarnished

Sen. Glenn was elected to a third six-year Senate term in 1986, and faced his first major political turmoil in 1990-91. He became the subject of a Senate Ethics Committee investigation into his role as one of the "Keating Five," senators who received large campaign donations from the savings-and-loan kingpin Charles Keating and later did favors from him. Sen. Glenn's assistance included a well-documented meeting in which he told regulators to either take action against Keating's banks or get off their backs.

Ultimately, the committee concluded there was no evidence Sen. Glenn did anything wrong initially, though it found he "exercised poor judgment" in organizing a lunch between Keating and House Speaker Jim Wright eight months after Sen. Glenn learned of Keating's legal problems.

If Sen. Glenn's all-American image was tarnished nationally, it remained aglow in the Buckeye State. His 1992 reelection made him the first popularly elected Ohio senator to win four consecutive elections.

Sen. Glenn was a liberal who supported education and health care, and a leader on issues regarding the control of nuclear weapons. He put out his own newsletter on the dangers of nuclear proliferation.

In 1997, the liberal Americans for Democratic Action gave Sen. Glenn a score of 80 out of 100 on his voting record. The American Conservative Union scored him at zero. Yet Sen. Glenn always maintained he was a moderate, someone who cared about issues that most affected the lives of everyday people in his home state.

"I would hope it comes out that people think I represented the three-fourths of people who are in the middle of the spectrum in Ohio and represented them well," he said.

The world's oldest astronaut

On Feb. 20, 1997, the 35th anniversary of his orbital flight, Sen. Glenn announced that he would not seek a fifth term, citing his age - he would be in his 80s if he served all six years. Less than a year later, on Jan. 15, 1998, he was back in the news for another, altogether extraordinary announcement: He was returning to space, having persuaded NASA to make him the world's oldest astronaut.

For the first time in years, the nation's attention turned to the space program, captivated by the romantic notion of a legendary astronaut returning to the scene of his greatest glory.

Sen. Glenn's job title would be "payload specialist," and he insisted his value to the mission was medical research, not public relations. Scientists hoped to find clues to the mechanisms of aging by putting a senior citizen into an environment known to bring on similar changes.

Sen. Glenn subjected himself to a rigorous schedule of geriatric tests on the flight, giving blood and urine, taking pills to measure protein production, injections to study muscle atrophy, and even swallowing a small transmitter to measure his core body temperature. He slept with electrodes in his scalp and a respiration sensor under his nose.

"I'm very proud to have been part of the beginning of the space program and I'm proud to be back," he said before liftoff.

Critics suspected that Sen. Glenn was a pawn in a NASA publicity stunt to revive lagging enthusiasm for the space program and surmount the lingering trauma of the 1986 Challenger disaster. "It's about John keeping his name in the paper," contended former Apollo astronaut Edgar Mitchell. "He wants to keep life interesting for himself."

Sen. Glenn's wife and children staunchly opposed the flight - they feared for his safety. "Do I want him to do it? No," his daughter told Newsweek. "Would I ask him not to do it? Never. This is who he is."

Former astronaut and Philadelphia native Scott J. Horowitz met Sen. Glenn when he returned to space, and considered him a hero. Horowitz, now an aerospace consultant in Utah, grew up in the 1960s and had been following Sen. Glenn's career since childhood.

"My generation grew up with the space program, which was a phenomenal motivator," Horowitz said.

Horowitz was stationed at the Johnson Space Center when Sen. Glenn prepared for his shuttle flight. He said he was impressed to see him in fine form.

"He was in incredibly good shape," he recalled. "He was gung-ho, doing all the stuff in the training and smiling about it. He hadn't lost a lot of his edge. Obviously he was a bigger-than-life individual. It's sad every time you lose one of your heroes."

President Bill Clinton attended the shuttle liftoff on Oct. 29, 1998, the first president to witness a space launch since Richard M. Nixon sat in pouring rain to watch Apollo 12 go up in November 1969.

Discovery and its crew settled into orbit 345 miles above the Earth, converting their ship into a laboratory for more than a week of science experiments that ranged from astronomy to zoology. "John has a smile on his face, and it goes from one ear to the other one, and we haven't been able to move it yet," shuttle commander Curtis Brown reported a few hours into the mission.

Sen. Glenn was euphoric. "Zero G, and I feel fine," he said in his first radio transmission to mission control, echoing the words he spoke during his orbital flight.

An orator in orbit

During one part of the flight, Sen. Glenn shared his love of space, science, and exploration by answering questions from children who spoke to him via radio hookup from two museums and John Glenn High School in Ohio.

"Much of what we'll learn in the future will come from space," Sen. Glenn told high school students at the Newseum in Arlington, Va. "It's going to be a tremendous benefit to all the young people today."

Sen. Glenn told a student in New Concord to study as hard as possible and be ready to grab opportunities. "I was lucky to have some good opportunities in my lifetime, this being one of them, and had the background to make the best out of it," he said.

Something about being in orbit brought out the orator in Sen. Glenn, not a particularly elegant speaker during his 40-year public career. In space, he was surprisingly eloquent in attempting what astronauts say is nearly impossible: describing the beauty of Earth from space.

No one expected that several days of experiments on a fit former jet pilot who exercised regularly would solve the mystery of aging. But scientists believed they might learn from Sen. Glenn's willingness to subject himself to the double stress of natural old age and the artificially induced aging of space flight. And it was clear that Sen. Glenn had again pushed the envelope, this time by changing the perception of what older Americans could and could not do.

"No one is going to look at Granddad the same way when John Glenn gets back," said gerontologist Robert Butler.

After his final mission, Sen. Glenn intended to have his life's mementos shipped to Ohio State, which is building a $20 million institute in his name. There are plans to turn his childhood home into a museum, though Sen. Glenn balked when asked how he'd liked to be remembered.

"This may sound strange, but I've never really sat back and thought about it," he told Newsweek. "I'm not done yet."

Sen. Glenn is survived by his wife and children.

Sen. Glenn's body will lie in state at the Ohio Statehouse in Columbus for a day, and a public memorial service will be at Ohio State's Mershon Auditorium, with dates to be announced, according to the Columbus Dispatch. Burial at Arlington National Cemetery will be private.

@JeffGammage

Staff writer Tom Avril contributed to this article, which also contains information from the Associated Press.