Ariane 5 Rocket Poised For 4:50 PM Launch

The countdown to a second attempt to launch an Ariane 5 rocket is under way at a South American spaceport as Europe aims to send a huge cargo carrier on a supply run to the International Space Station.

The powerful Ariane 5 and its cargo -- an Automated Transfer Vehicle the size of a double-decker bus -- is scheduled to blast off at 4:50 p.m. The rocket and its payload must be launched at that precise time to put the cargo carrier on course for the international outpost. Otherwise, the launch would have to be put off until Thursday.

You can watch the action live here in The Flame Trench. Click the NASA TV box on the right to launch our NASA TV viewer and live coverage of the launch attempt.

Mission managers have sorted out a data system problem that halted countdown to an initial launch attempt on Tuesday four minutes and one second before a planned liftoff.

Officials say there is heavy rain in areas around the Guiana Space Center in French Guiana and that there is a chance lightning might prompt a launch delay.

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