Shuttle launch rescheduled for today

Nasa will try today to launch space shuttle Discovery on its final voyage, although stormy weather could force yet another delay.

Mission managers met into the evening to discuss an electrical problem that forced the latest postponement.

They concluded the circuit breaker trouble no longer exists and the shuttle is safe to fly.

But forecasters warned there is an 80% chance that thunderstorms will keep Discovery on the pad. Lift-off is scheduled for 3.29pm (7.29pm Irish time).

The decision came as dark storm clouds rolled over the launch site in Florida, putting some launch preparations on hold.

Managers will reconvene before daybreak to assess the weather, before loading the shuttle's fuel tank.

"If the forecast tomorrow morning is still as bad as it is today, there's a chance" that today's launch attempt will be called off, mission management team chairman Mike Moses said last night.

"It's too early to make that call right now."

Discovery's flight to the International Space Station was first stalled by gas leaks last week.

Then a problem cropped up on Tuesday with a computerised controller for one of the main engines. At this point, the mission is running three days late.

The space agency has until Sunday to launch Discovery. Otherwise, it will have to wait until December because of sun angles.