Today Gagarin became the first human to travel into space

On 12 April 1961, Gagarin became the first human to travel into space in Vostok 3KA-2 (Vostok 1) and return. His call sign in this flight was Kedr (Cedar). During his flight, Gagarin famously whistled the tune "The Motherland Hears, The Motherland Knows". The first two lines of the song are: "The Motherland hears, the Motherland knows/Where her son flies in the sky". This patriotic song was written by Dmitri Shostakovich in 1951 (opus 86), with words by Yevgeniy Dolmatovsky.

There are speculations in the media that from orbit Gagarin made the comment, "I don't see any God up here." There are, however, no such words in the full verbatim record of Gagarin's conversations with the Earth during the spaceflight. In a 2006 interview a close friend of Gagarin, Colonel Valentin Petrov, stated that Gagarin never said such words, and that the phrase originated from Nikita Khrushchev's speech at the plenum of the Central Committee of the CPSU, where the anti-religious propaganda was discussed. In a certain context Khrushchev said, "Gagarin flew into space, but didn't see any God there". Colonel Petrov also said that Gagarin had been baptized into the Orthodox Church as a child.

While in orbit Gagarin was promoted "in the field" from the rank of Senior Lieutenant to Major, and this was the rank at which TASS announced him in its triumphant statement during the flight.[citation needed]

Gagarin being safely returned, Nikita Khrushchev rushed to his side and Gagarin issued a statement praising the Communist Party of the Soviet Union as the "organizer of all our victories". Khrushchev saw Gagarin's achievement as a vindication of his policy of strengthening the Soviet Union's missile forces at the expense of conventional arms. This policy antagonized the Soviet military establishment and contributed to Khrushchev's eventual downfall.

After the flight, Gagarin became an instant, worldwide celebrity, touring widely with appearances in Italy, Great Britain, Germany, Canada, and Japan to promote the Soviet achievement.

In 1962, he began serving as a deputy to the Supreme Soviet. He later returned to Star City, the cosmonaut facility, where he worked on designs for a reusable spacecraft. Gagarin worked on these designs in Star City for 7 years.

Gagarin became Lieutenant Colonel (or Podpolkovnik) of the Soviet Air Force on June 12, 1962 and on November 6, 1963 he received the rank of Colonel (Polkovnik) of the Soviet Air Force.