“On 12 April 1961, the Vostok 3KA-3 (Vostok 1) spacecraft with Gagarin aboard was launched from Baikonur Cosmodrome. Gagarin thus became both the first human to travel into space, and the first to orbit the Earth. His call sign was Kedr (Russian: Кедр, Siberian pine or Cedar).
The radio communication between the launch control room and Gagarin included the following dialogue at the moment of rocket launch:
Korolev: "Preliminary stage..... intermediate..... main..... lift off! We wish you a good flight. Everything is all right."
Gagarin: "Поехали!" (Poyekhali!—Let's go!).
Gagarin’s informal poyekhali! became a historical phrase in the Eastern Bloc, used to refer to the beginning of the Space Age in human history.”