Why a spacewalk is no cakewalk

Cosmonauts put through grueling training regime before blastoff

STAR CITY, Russia - Wearing helmets weighing 100 kilos, spinning in a centrifuge and exercising while weightless: Russian cosmonauts and astronauts from abroad have to undergo a grueling training process before blasting off into space.

Helped by an instructor at the famed Star City outside Moscow, cosmonaut Sergei Ryazansky slowly puts on his helmet as he hangs from the ceiling suspended by a thick metal cord and practices opening a lock while wearing a thick spacesuit.