On June 5, 1968, the day that his close friend, presidential candidate Robert F. Kennedy, was mortally wounded in the kitchen of the Ambassador Hotel in (Los Angeles, John Glenn and his wife, Annie, flew with five of RFK's 10 children back to the Kennedy home at Hickory Hill in McLean, Va. The next morning it was Glenn, having received the news in the middle of the night, who sat on their beds and gently woke each of the children to tell them their father had died. "It was one of the hardest things I ever did," he would later say.

Afterward, wandering in Kennedy's study, Glenn found a book on his friend's desk open to a passage by Ralph Waldo Emerson. He committed the words to memory, and in the years since has often used them as a parting thought in his public speeches: "If there is any period one would desire to be born in, is it not the Age of Revolution?"

John Glenn has not only lived in such a time, he helped define it. On a clear Florida morning in 1962, 10 months after Soviet cosmonaut Yuri Gagarin was hurled into orbit, Glenn, 40, riding in a cramped titanium capsule dubbed the Friendship 7, electrified the country by becoming the first American sent into space to circle the globe. If all goes as planned, on the morning of Oct. 29, 1998, Glenn, now 77 and at the end of a 24-year Senate career, will aim at yet another horizon. Taking his mid-deck seat on the shuttle Discovery and, courtesy of the Smithsonian Institution, carrying a scrap of wing fabric from the plane the Wright brothers first flew in 1903 at Kitty Hawk, N.C., Glenn will lift off from Cape Canaveral for a nine-day mission as the oldest human being ever launched into space. "It was an exciting time, an adventurous time," said the taciturn septuagenarian, recalling his historic flight at a January press conference announcing his return to space. "I can't help but stand here before you with a real sense of déjà vu."

There will be reminders of just how much time has elapsed since his original 4-hour, 55-minute flight. This time around, Glenn will take orders from Discovery commander Curt Brown, who was just shy of 6 years old at the time of Friendship's launch. And when Glenn returns, he will be welcomed by his two grandsons, 16 and 14, the very ages Glenn's own two children were when their father first ventured into space.

The flight has not been free of controversy. Glenn and his crew-mates have been visibly irked by complaints that his trip is little more than a public relations ploy by a space agency struggling with budget cuts and flagging public interest. "If we can motivate or excite more people about the space program, that can only help," says Brown. "But that's not what this flight is for." Explains Glenn, a member of the Senate's Committee on Aging: "The changes—balance problems, cardiovascular changes and muscle breakdown—that happen to astronauts in orbit also occur as a part of the aging process, and I thought it was a very valuable area of research."

To that end he will, during Discovery's voyage, provide blood and urine samples and wear 21 sensors monitoring everything from respiration to brain-wave patterns. By liftoff he will have spent more than 500 hours in training, shimmying down an escape pole, being dropped (in full gear) 25 feet into a pool of water and weathering multiple G-forces in a centrifuge. "Even learning how to use the toilet on the spacecraft is new," he said. "The last time, I wasn't up long enough [to need it]."

Few who know him doubt that Glenn still has the right stuff. "For privacy reasons I can't tell you what he went through on his physical, but it wasn't just a few blood samples," says NASA administrator Daniel Goldin, who made the decision to send him. "Let's just say he's the most tenacious human being on the face of the planet." And maybe the happiest. "The guy's so excited," says his buddy astronaut Gene Cernan, 64, "he might as well be 15 years old again."

It was in those simpler times that Glenn, the older of two children, first took an interest in flight. Born in Cambridge, Ohio, shortly before his father, John Herschel, a plumbing-and-heating store owner, and mother, Clara Sproat, a former schoolteacher, moved to nearby New Concord, Glenn spent hours making model airplanes as a boy. "I used to fly them, and they'd crash," he says, "and I'd put them back together and fly them again." One day at a small grass airstrip, when a man in a real plane offered them a ride, "Dad decided it would be great if we went up, so he and I sat together in the little back seat, strapped in the open cockpit. I was fascinated with aviation from then on."

That and Annie Castor, daughter of a local dentist. "John wasn't popular with the girls, because he only had one," says childhood friend Lloyd White, a retired Methodist minister. By eighth grade, Glenn and Annie were going steady and marching together in the school band; he on trumpet, she on trombone. One thing she liked about him was that he wasn't bothered by the severe stutter that she later conquered as an adult. "John was always very patient about my speech," she told PEOPLE in 1980. "All the time we went together, he never mentioned it."

After enrolling at Muskingum, a Presbyterian college in New Concord, Glenn got his pilot's license and planned to do medical research. But when, during his junior year, he heard about the bombing of Pearl Harbor on his car radio, he came to two decisions: He would enlist in the Marines, and he would marry Annie—which he did, on April 6, 1943. "John only made one promise to me on that wedding day," she says. "He said life would never be dull."

He was a man of his word. After fighter training near San Diego, Glenn was off to the South Pacific, where he flew 59 combat missions. "My plane was hit five times," says Glenn, who earned 20 medals over his career, including 6 Distinguished Flying Crosses and the Congressional Space Medal of Honor. "Some were single bullet holes, but one took a big chunk out of the leading edge of the wing." After the war, the Glenns—now with an infant daughter, Lyn, and a 2-year-old son, David—touched down at a number of bases, landing in Corpus Christi, Texas. Before returning to war in Korea, Glenn trained on the Air Force's first jets. He flew 90 missions, and in the last nine days of the fighting shot down three MiGs. After the war, Glenn trained on supersonic jets, and in July 1957 set a record with a 3-hour, 23-minute flight from L.A. to New York in an F8U Crusader.

But his biggest flying challenge lay ahead. In 1958, while stationed at the now-defunct Navy Bureau of Aeronautics, he heard about NASA's fledgling space program. "They were looking for test pilots," he says, "and I had just come off that duty. So I applied." In April 1959, Glenn and six others were selected from a pool of some 130 applicants to become the Mercury 7 astronauts. True to Tom Wolfe's portrayal in his 1979 book The Right Stuff, the straitlaced Glenn "was very concerned, 24 hours a day, about what our reputation was," says fellow astronaut Gordon Cooper, 71, now a Van Nuys, Calif., aerospace consultant. "It was a bit higher priority with him than some of the rest of us."

Despite his eagerness to be the first in space, Glenn was passed over for the first two launches. "When Al Shepard was picked to be the first, John didn't say much. He just got sort of withdrawn," says longtime friend Tom Miller, now a retired lieutenant general. "When [Gus] Grissom got the second flight, I was afraid for him, he was so depressed." When he finally drew duty, a determined Glenn dropped 40 pounds to meet the capsule's critical weight limit. "His body was in good shape, but his eyeballs were set way back in his head," says Miller. "He looked like death warmed over." When the time came, Glenn and Annie spoke a farewell practiced over his years in the military. "I'm going down to the corner store and buy some chewing gum," Glenn would say. "Well," replied Annie, "don't take too long." Still, according to an account in LIFE, when Friendship 7 blasted off, Annie, who had once witnessed the launchpad explosion of an unmanned Atlas rocket, "put her head against her knees and sobbed."

His takeoff was flawless, but Glenn suffered a serious scare when it looked as if his heat shield might fail ("I saw big burning chunks of something coming back past the window," he recalls). Despite worldwide acclaim, Glenn did not return to space. Years later he learned that his friend President John F. Kennedy was responsible. "I don't know if he was afraid of the political fallout if I got killed," Glenn told TIME, "but by the time I found out, he had been dead for some time, so I never got to discuss it with him."

Instead, in 1964, inspired by the Kennedys, Glenn quit NASA and shifted his focus to a campaign for the Senate—at least until a bathroom fall damaged his inner ear and forced him to withdraw. Afterward, between becoming a vice president for the Royal Crown Cola Co. and an investor in several Holiday Inns, he lost a second Senate bid in 1970. "I may have been almost too well known," he says. At rallies, "some little kid in the front row would always ask, 'Mr. Glenn, do astronauts really drink Tang?' " He finally won his Senate seat in 1974, though a 1984 run for the Presidency failed miserably. "He would come to a fund-raiser and stand in a corner talking to Annie or a Secret Service guy, rather than going through the room begging people he didn't particularly respect for money," says Scott Miller, then his media consultant. "I admired him enormously, but he is one of the worst politicians."

Over four terms in the Senate, Glenn worked tirelessly as a member of the committees on armed services, aging, governmental affairs and intelligence, on what even he refers to as "MEGO issues—for 'My Eyes I Glaze Over,' " says former committee staffer Paul Light. In 1991 the only tarnish to his political career came in the form of a mild reprimand from the Senate Ethics Committee, which named him one of two senators who had used "poor judgment" in appearing to arrange political favors for Charles Keating, a California financier convicted of bilking his savings and loan out of more than $2 billion.

Having been an effective, if not preeminent, senator, Glenn announced his retirement in February 1997, on the 35th anniversary of his Mercury mission. "Although my health remains excellent and my passion for the job burns as brightly as ever," he said, "there is still no cure for the common birthday." What few knew was that two years earlier he had already begun lobbying to return to space.

Initially, the stiffest opposition to Glenn's final flight may well have come from his wife, who now supports his mission. "You might say I had given John to our country for almost 55 years," says Annie, now 78, "and I was ready to take him as my own." That time will come, Glenn promises, not long after he returns to Washington to vacate his Senate office just across the Mall from where his well-worn flight suit and battered Friendship 7 space capsule are on display at the National Air and Space Museum. Those artifacts, which may soon be joined by items from his final venture into space, will be the things by which John Glenn is remembered. Those and the words he ends his speeches with—a closing line from Emerson: "This time, like all times, is a very good one if we but know what to do with it."

Susan Schindehette
Margery Sellinger and Macon Morehouse in Washington, Laurel Brubaker Calkins in Houston and Lorna Grisby in Chicago

  • Contributors:
  • Margery Sellinger,
  • Macon Morehouse,
  • Laurel Brubaker Calkins,
  • Lorna Grisby.