On Feb. 20, 1962, John Glenn blasted into the history books when he became the first American to orbit Earth.
The three-orbit flight of Friendship 7 electrified the nation with good cause, 10TV's Jerry Revish reported.
The U.S. was in the depths of the Cold War and seemed to be losing the space race to the Soviet Union.
"They were claiming superiority to the United States and saying they could prove it because their rockets were successfully launching and going around the Earth, at a time when ours were too often blowing up on the launch pad," Glenn said.
Glenn reflected on what happened in 1962 from his office at The Ohio State University with Revish.
Glenn said that the astronauts were used to danger. They were all pilots who pushed the limits to test new kinds of aircraft.
"They had talked at one time about having sea divers and frogmen and people who had been in dangerous situations," Glenn said. "(President Dwight) Eisenhower was the one who made the decision that they were going to be military test pilots."
The pilots knew the strengths of the spacecraft they would fly.
"We were back and forth to the McDonald plant in St. Louis where they were putting the whole thing together," Glenn said. "We worked closely with the engineers and they came and briefed us. So we were an integral part of the team putting the whole thing together."
According to Glenn, the astronauts also knew its weaknesses and insisted that astronauts not be passengers, but pilots -- with a control stick -- not just an autopilot.
Though the flight date had been set and scrubbed 10 times, the control stick became critical once Glenn finally blasted off.
"At the end of the first orbit, the automatic control system went out. And had a foul-up, and I could take over manually and fly that, which I did," Glenn said.
Without it, Glenn would have streaked off-course, at 17,500 mph. As it was, he barely made it into orbit.
"I had about -- I think it was, they figured - 1 ¾ seconds of fuel remaining," Glenn said. "It was very tight on whether you're going to make it into orbit or not."
While orbiting, Glenn performed a series of experiments. Scientists had no idea if the human body could tolerate space flight. Eye doctors worried that zero-gravity might alter the shape of the eyes.
"Your vision might change enough, you might not even be able to see the instrument panel, to make an emergency re-entry if you had to," Glenn said. "They taped up a miniature eye chart that was up at the top of the instrument panel. I was supposed to read that every 20 minutes during flight, to see whether I was going to change or not."
In the second orbit, there was more trouble, Revish reported. At the base of the capsule was the heat shield, to prevent Glenn from burning up on re-entry when he plunged down through the Earth's atmosphere.
"There had been an indication going down to the ground that the heat shield was loose," Glenn said.
On the ground, NASA's Mission Control did not want to give the bad news to Glenn. He said he insisted on knowing what was wrong with his aircraft.
The retro pack sat in the middle of the heat shield. Mission Control decided to leave the retro pack in place, hoping it would keep the heat shield on.
"There were chunks of the retro pack that were breaking off and coming back past the window, flaming as it came by," Glenn said. "It made for a very spectacular re-entry from where I was, watching these chunks come off."
At the time, Glenn said that he did not know what was burning up and whether he would live or die. Neither did the world watching below.
Twenty-five minutes after splashdown, Glenn was picked up by a U.S. destroyer.
"I don't think any of us thought it would receive the amount of attention it did," Glenn said. "It sort of took over."
Glenn received honors in Ohio and in his hometown of New Concord, along with a a tickertape parade on Broadway. He was the new American hero.
In 1964, Glenn decided to leave the U.S. Marines to enter politics. He made it into space and back safely, but during his first run for the U.S. Senate he was suddenly left incapacitated for nine months. Glenn was trying to adjust a bathroom mirror in his rental apartment on East Broad Street when the mirror slipped from his hand.
"It broke over my head, and the next thing I knew I was sort of on one knee on the floor," Glenn said. "When it hit me, I fell an on the metal rail along the bathtub. I hit my head right above the left ear here."
Glenn spent six weeks in a hospital, nine months more recuperating from intense dizziness that affected his balance. He was determined to run for the Senate again. After he won in 1974, he served as an Ohio senator for 24 years and even made a presidential bid. Through it all, Glenn retained his passion for space. He asked to join a Space Shuttle crew.
"If I thought I was going to be eligible for this, I'd have to pass all the physicals that anybody else did," Glenn said.
In 1998, NASA announced that Glenn would fly on Discovery. A crew of seven shot into a blue Florida sky and orbited the earth. At 77, Glenn was aboard. He was the only one of the original seven astronauts to ride the Space Shuttle.
Glenn said that the purpose of the entire space program had changed by 1998, and the concentration of the mission was conducting basic research.
"We had 83 different research projects on one flight," Glenn said.
NASA scientists knew that astronauts experienced changes in their bodies that were similar to the aging process. Glenn volunteered to help test changes in bones and in the immune system.
"Twenty-one different body parameters were being recorded. Brain waves, spandex vest that would give you rate of respiration and volume, EKGs," Glenn said. "(I) did that continually for four days."
Glenn said that the early days in space sparked the imagination of a generation, and encouraged more children to study science. In 50 years, what scientists learned from the space program produced advances in everything, from medicine to computers.
"With that little combination of educated people and the research that was done, we just leapfrogged ahead of the rest of the world," Glenn said.
Glenn now has an office at Ohio State in the John Glenn School for Public Affairs, where he encourages young people to enter politics and change the world for the better.
His wife, Annie, has been with him since early childhood. This spring, they will celebrate 69 years of married life.
"You have to pick a woman that you look up to and is better than you are," Glenn said. "I've spent 68 years trying to catch up."
Both John and Annie are 90. They can look back to when John was in the Marines, a test pilot, a Mercury astronaut, a senator and a shuttle astronaut, but they would rather look forward.
"We've had a wonderful life and are having a wonderful life," Glenn said.
The shuttle fleet retired last July. Glenn said that he looks forward to the return of American manned space flight when private companies take over in a few years.
The only way astronauts are now currently accessing the International Space Station is by Russian rockets.