The Soviet Union has beaten the USA in the race to get the first man into space.
At just after 0700BST, Major Yuri Alexeyevich Gagarin was fired from the Baikonur launch pad in Kazakhstan, Soviet central Asia, in the space craft Vostok (East).
Major Gagarin orbited the Earth for 108 minutes travelling at more than 17,000 miles per hour (27,000 kilometres per hour) before landing at an undisclosed location.
The Soviet leader Nikita Khrushchev has congratulated Major Gagarin on his achievement.
He sent the cosmonaut a message from his holiday home on the Black Sea.
“The flight made by you opens up a new page in the history of mankind in its conquest of space,” Mr Khrushchev said.
The Soviet news agency, Tass, made the first official announcement of Major Gagarin’s flight at just before 0800BST.
Radio Moscow then interrupted its schedule to give details to a jubilant nation.
Major Gagarin’s safe return has laid to rest worries that space flight would be fatal for humans.
It is also a blow to the Americans who had hoped to be the first to launch a man beyond Earth’s atmosphere.
However, President Kennedy has congratulated the Soviets on their achievement.
It would be some time before the United States caught up with the Soviets in the fields of rocket boosters, the president added.
Rumours that a Soviet launch attempt was imminent began some days ago.
It was the culmination of two years of highly secretive training for Yuri Gagarin, 27, who beat off thousands of other hopefuls.
The previously obscure army major has returned to earth a national hero.
He has already been awarded the title of “Master of Radio Sport of the Soviet Union” and a big reception for him at the Kremlin in Red Square is being planned.
Courtesy BBC News
In context
The USSR notched up a series of space firsts beginning with the launch of the world’s first man-made satellite, Sputnik, in 1957.
Later the same year they sent a dog called Laika into space.
Valentina Tereshkova became the first woman cosmonaut in 1963 and two years later Alexei Leonov became the first man to perform a space walk.
However, the Americans did beat the Soviets to the Moon with the flight of Apollo 11 in July 1969.
Yuri Gagarin became an international icon but was disappointed to be banned from more space missions because the Soviet state considered him too valuable a propoganda asset to risk his life.
In 1968 he was killed in a plane crash just outside Moscow in what some people believed were suspicious circumstances.