April 12

Cosmonautics Day is a holiday celebrated in Russia and some other former USSR countries on April 12. This holiday celebrates the first manned space flight made on April 12, 1961 by the 27-year-old Soviet cosmonaut Yuri Gagarin. Gagarin circled the Earth for 1 hour and 48 minutes aboard the Vostok 1 spacecraft. Coincidentally, it is also the anniversary of the first Space Shuttle launch that occurred 20 years after the historic Vostok flight.
The holiday was established in the Soviet Union one year later, on April 9, 1962. In modern Russia, it is celebrated in accordance with Article 1.1 of the Law "On the Days of Military Glory and the Commemorative Dates in Russia". Gagarin's flight was a major success for the Soviet space program, and opened a new era in the history of space exploration. Gagarin became a national hero of the Soviet Union and eastern bloc and a famous figure around the world. Major newspapers around the globe published his biography and details of his flight. Moscow and other cities in the USSR held parades, the scale of which were second only to WWII Victory Parades. Gagarin was escorted in a long motorcade of high-ranking officials through the streets of Moscow to the Kremlin where, in a lavish ceremony, he was awarded the highest Soviet honour, the title of Hero of the Soviet Union, by the Soviet leader Nikita Khrushchev.

Until today the commemoration ceremony on Cosmonautics Day starts in the city of Korolyov, near Gagarin's statue. Participants then proceed under police escort to Red Square for a visit to Gagarin's grave in the Kremlin Wall Necropolis, and continue to Cosmonauts Alley, near the Monument to the Conquerors of Space. Finally, the festivities are concluded with a visit to the Novodevichy Cemetery.
On April 7, 2011 United Nations General Assembly adopted a resolution declaring April 12 as the International Day of Human Space Flight.