Nasa delays launch of space shuttle Endeavour on mission STS-127

Nasa called off the launch of the space shuttle Endeavour with just hours to spare on Saturday morning amid alarm over a leaking fuel line.The space agency halted the countdown clock less than 7hours before the scheduled 7.17am lift-off from Kennedy Space Centre at Cape Canaveral, Florida, after highly volatile hydrogen gas was found to be escaping from the external tank during the final stages