On April 12, 1961, Soviet cosmonaut Yuri Alekseyvich Gagarin became the first human being to travel into space. Aboard spacecraft Vostok 1, Gagarin orbited the Earth at a maximum altitude of 187 miles. His space flight lasted roughly under 2 hours. Back on Earth, he became an instant hero and celebrity. Gagarin traveled the world to spread the word of Russia's successful space trip. Gagarin died on March 27th, 1968 in a routine training flight that ended in a fatal crash. There are many speculations and conspiracy theories about the reason why his aircraft failed.