This 15 kopeck stamp from the Soviet Union, issued in 1986, commemorates Cosmonautics Day (День Космонавтики), celebrated annually on April 12. The design honors Yuri Gagarin, the first human to journey into outer space in 1961 aboard Vostok 1. The artwork features a stylized bust of Gagarin set against cosmic imagery — Earth, satellites, and a rocket ascending into orbit — symbolizing Soviet achievements in space exploration. The bold blue-violet tones and radiant composition embody national pride in the USSR’s pioneering role during the Space Age.