A three-man crew blasted off from a space centre in southern Kazakhstan on board a Russian-made Soyuz craft for a half-year stay at the International Space Station.

Two astronauts who were teaching maths and science to middle school students just five years ago went on a spacewalk together, but could not free a jammed equipment shelf no matter how hard they tried.

Nasa, confronted again with orbiting junk, ordered the astronauts aboard the linked space station and shuttle Discovery to move out of the path of a piece of debris.