A fresh fuel leak has disrupted the launch of the space shuttle Endeavour, Nasa officials say, BBC reported.
The shuttle is due to launch on Wednesday morning, but hydrogen gas has leaked from a vent line on the space shuttle's external fuel tank.
A previous fuel leak postponed the shuttle's launch on Saturday.
The shuttle's seven crew is to fly to the International Space Station (ISS) to deliver the last element of a Japanese laboratory aboard the station.
If the launch is again postponed, the next international space station construction mission will not take place until next month.