People have always dreamt of travelling in space and reaching other planets. At the beginning of the 20th century a famous Russian scientist Tsiolkovsky said that mankind will not live on planet Earth forever. His predictions came true half a century later, when the first artificial satellite was launched. It was on October 4, 1957. The satellite was called Sputnik-1. However, the most important event in space exploration took place in on April 12, 1961, when spaceship “Vostok” with a man on board was launched into space. This first man who overcame gravitation was Yuri Gagarin. After successful orbiting, he returned to the Earth. This flight encouraged many other Russian cosmonauts to explore the outer space. Among them, Titov, Nikolaev, Tereshkova, Leonov, Savitskaya and others.