April 12 will mark the 50th anniversary of Russian cosmonaut Yuri Gagarin’s historic 108-minute flight into space, in which he completed a single Earth orbit, sparking a space race with the United States and becoming an international hero. Even so, Russia has felt it necessary to released top-secret documents to fight rumours that Gagarin was murdered by Soviet rulers, Reuters reports. Today, in Russia’s Star City, the world’s oldest space-flight training centre, still looks in some ways like a shrine to Gagarin, who died in a plane crash just seven years after his flight. A mural of Gagarin, who completed the space flight at age 27, leads into a museum filled with artifacts like his orange-brown space suit, gifts from dignitaries, and a recreation of his office. One photo shows his orbiter, scorched from the landing, lying in a Russian field, where he was famously offered milk and bread by a farmworker upon landing. Conspiracy theorists have said Gagarin was murdered on the orders of Soviet leader Leonid Brezhnev, but last week, the government declassified its archives to show Gagarin probably lost control of his jet after swerving to avoid a weather balloon.