Major Yuri Gagarin, the Russian astronaut, waves his greeting to spectators as he leaves the Soviet Embassy in London, United Kingdom on July 15, 1961, after his visit to Britain. He was mobbed by hundreds of onlookers and well-wishers as he drove from the embassy to London airport. (AP Photo/Dennis Lee Royle)

Soviet spaceman Yuri Gagarin waves after he arrived at the London Airport July 1, 19611 for a private visit as the guest of the Russian Trade fair. The welcoming committee was headed by a virtually unknown civil servant, secretary to Lord Hailsham's Science Ministry. Several newspapers criticized the Government for not giving Gararin a real hero's welcome even though he came on a private visit. (AP Photo)

Soviet cosmonaut Yuri Gagarin waves as he arrives at a London airport, Jul. 11, 1961. (AP Photo)

Yuri Gagarin and Nikita Khrushchev at Vnukovo airport during his welcome in Moscow after his flight on April 14, 1961. (AP Photo/ITAR-TASS)

This photo, released by TASS. the official Soviet news agency, shows the blastoff of the space vehicle Vostok 1, carrying Soviet Major Yuri Gagarin on his recent space flight. The blunt-nosed rocket rises through the clouds after launching from an undisclosed site, April 12, 1961, somewhere in the Soviet Union. (AP photo/Tass)

People gather on the Red Square, 12 April 1961, to celebrate the flight of Soviet Cosmonaut Yuri Gagarin, the first human to travel in space aboard Vostok I and the first to orbit the Earth. Yuri Gagarin died in a plane crash on a MIG-15 on a routine training flight, 27 March 1968. He was given a state funeral and was buried in the Kremlin wall facing Red Square.

Soviet Air Force Major Yuri Gagarin, shown in an undated photo, became the first space traveler in history, April 12, 1961. Gagarin made the historic flight in the spaceship Vostok 1; traveled at 18,000 miles an hour and stayed in orbit for an hour and three quarters before making a safe landing in a predetermined area. (AP photo/TASS)

First Soviet cosmonaut Yuri Gagarin runs during a test in Star City, Russia, in Nov. 1959. In 108 minutes on April 12, 1961, the 27-year-old Gagarin made man's first orbit of the Earth. (AP Photo)