Yuri Gagarin. First man in space. For the rest of history his name will rank -- perhaps with Columbus, Magellan, Marco Polo and Neil Armstrong's -- among the world's greatest explorers. He was, after all, the first ever to leave the world behind.
On the morning of April 12, 1961, Gagarin, then 27, flew Vostok 1 on a single orbit of the Earth. It took him 108 minutes. He launched from the Baikonur Cosmodrome in the Soviet Union, reached a maximum speed of about 17,500 mph and an altitude of 203 miles, and was a hero by the time the sun rose over the eastern United States.
But flying as he did in the most chilling years of the Cold War, his trip was kept secret by the Soviet government until it was almost over. So myths and mystery abound about his flight, even today. Below, some surprising facts about Yuri Gagarin's flight, and a few falsehoods we hope to help debunk. Ten, nine, eight....
7. Gagarin Was Not the First
Even now, 50 years later, conspiracy theories abound: that the Soviets launched men as early as 1958 but could not get them back down, that a cosmonaut was killed in a launch attempt only five days before Gagarin's flight.
For lack of records from early Soviet space program, we may never know for sure, but Western students of space flight seem to agree that Gagarin was genuinely the first to fly in space.
So why did theories take root? Perhaps because everyone loves a good spy story, but also because the Soviets were so famously secretive (the name of Vostok's designer, Sergei Korolyev, was unknown in the United States until after his death).
"During the Cold War, everything that we knew about Gagarin was filtered through the official Soviet media or through rumor and hearsay in the West," wrote Asif A. Siddiqi, a Fordham University historian of the early space age, in an email from Moscow to ABC News. "Many people in the West didn't trust the former while there was never any reason to trust the latter."
6. Gagarin Was Almost Killed in Space
This is true, though it took the Russians 30 years to release the records showing what happened. Vostok 1 was a two-part spacecraft, with a spherical crew compartment for Gagarin, and an equipment module in back for rocket engines, fuel and support equipment.
As Gagarin neared the end of the flight, engines in the equipment module fired as scheduled to slow him out of orbit -- but the section failed to disconnect from the crew compartment for re-entry into the Earth's atmosphere. There was nothing anyone could do. With the two sections still mated, the ship might tumble out of control on the way down and crash in pieces.
Fortunately for Gagarin, the cables holding the two sections together gave way as the ship was buffeted violently by the upper layers of the air. Vostok landed safely in central Russia. Gagarin ejected from his capsule a moment before and parachuted to the ground on his own.
5. The Soviets Were Afraid Gagarin Would Go Crazy in Space
Before Gagarin buckled in for his famous journey, even those closest to the mission worried about what would happen to a man in space. Would he lose consciousness? Would he go mad?
"There were all kinds of wild fears that a man could lose his mind in zero gravity, lose his ability to make rational decisions," Oleg Ivanovsky, who oversaw the construction and launch of Gagarin's spacecraft, told The Associated Press. Even though Vostok's operation was automatic, controllers wondered if weightlessness could cause Gagarin to go crazy and try to take over command of the capsule. As added protection, the engineers added a three-digit security code that Gagarin would have to enter to command the spacecraft.
Ultimately, the point was moot. Gagarin's spacecraft launched -- and landed -- safely.
4. Gagarin Really Was Crazy
Well, no, he wasn't crazy, but he was preternaturally calm about risking his life. Russian accounts show that Korolyev, the chief designer, was so anxious about Gagarin's flight that he had chest pains, and didn't sleep the night before.
Gagarin, on the other hand, declined a sleeping pill and is reported to have slept well. Shortly before launch, his pulse was measured at 64 beats per minute. Not a sign of a worried man.
3. First Atheist in Space?
After the flight, Gagarin was widely quoted in the West as having said from space, "I don't see any God up here."
Not quite. Soviet leader Nikita Khrushchev said something similar after he welcomed the returning hero to Moscow. Gagarin, for his part, said he hummed a patriotic song in orbit:
"The Motherland hears, the Motherland knows/Where her son flies in the sky."
2. All the Soviets Really Wanted Was to Beat the U.S.
Partly true. Siddiqi writes that the Soviet target date for launching Vostok was determined by publicity about NASA's Project Mercury, which planned to launch its first man early in 1961. Gagarin beat Alan Shepard into space by all of 23 days.
But Vostok had been in the planning since at least 1959. And by sheer luck for the Soviets, the Americans had a rocket failure in 1960 that caused them to order one extra test flight -- in March 1961 -- before launching Shepard in May. If not for that, the Americans would have been first.
There is some irony here. True, Apollo 11 ultimately beat the Soviets to the moon in 1969. But the U.S. astronaut program has searched for direction since then, and the Obama administration has ordered a pause after the space shuttles finish assembly of the International Space Station this year. For several years after, the only way for Americans to launch into space may be on board Russian Soyuz spacecraft.
1. Yuri Gagarin, National Icon
By the mid-1960s, two space heroes stood above all others in the world's imagination: the American John Glenn and the Soviet Gagarin. Both were so popular that their governments worried about losing them by letting them fly again.
Glenn got the message. He left NASA after his Friendship 7 flight in 1962, running for the Senate and, later, the presidency. Only when his political career was winding down did he persuade NASA to let him ride the space shuttle Discovery in 1998. By then he was 77.
Gagarin was different, and he let his bosses know it.
"They basically thought he was too politically valuable to risk on a second flight," said Robert Pearlman, editor of the website CollectSpace.com. "He kept pushing it back into their faces that he wanted to fly."
Gagarin was killed in a jet accident in 1968, reportedly while training for a space mission. He was only 34 years old.
ABC News' Ki Mae Heussner contributed reporting for this story.