It has been half a century since Yuri Gagarin, the first space traveller, made the historic journey that put the Soviets ahead of the Americans in the space race.<br /><br />A mission to celebrate the 50th anniversary of human space flight has blasted off from Kazakhstan. <br /><br />The goal is to explore the potential for longer manned missions.<br /><br />With the US shuttle programme due to end this summer, NASA has agreed to pay Russia almost 63 million dollars per astronaut in the coming years. <br /><br />Al Jazeera's Neave Barker reports.