Yuri's Night is an international celebration held every April 12 to commemorate milestones in space exploration. It is named for the first human to launch into space, Yuri Gagarin, who flew the Vostok 1 spaceship on April 12, 1961. In 2011, the fiftieth anniversary of Gagarin's flight, Yuri's Night was celebrated at over 567 events in 75 countries on seven continents. Yuri's Night is often called the "World Space Party". The launch of STS-1, the first Space Shuttle mission, is also honored, as it was launched 20 years to the day after Vostok 1, on April 12, 1981.
