Forty years ago today, Soviet cosmonaut Yuri Gagarin became the first man to fly in to space. It was a short trip: one 108-minute circumnavigation of Earth, but it changed human history. When humankind escaped the bounds of the earth's atmosphere, our views of the world and our place in it changed forever.

Gagarin, who died in 1968 at the age of 34, was a former farm boy who fit the image of a Soviet "hero of the people." He was a down-to-earth figure, capable of being fashioned into the new Soviet man. Or maybe not: After his death, Gagarin was revealed to be less perfect than his press releases suggested, fond of both women and wine. In many ways, however, that seemed more fitting for the former carpenter's son who shouted "Let's go" when he climbed into the capsule for his historic flight.

Gagarin's mission was the fourth consecutive triumph for the Soviet space program. On Oct. 4, 1957 Soviet scientists put Sputnik, the first satellite, in orbit. A month later, Laika, a dog, became the first living creature in orbit. Two years on, a Soviet satellite made the long voyage to the dark side of the moon.