Lightning was still visible in the skies over Cape Canaveral as the launch time approached.

'If we had 30 more minutes to go I think we would have a real good shot,' said NASA technician Mike Moses.

However, Discovery did not have that extra time due to a limited time window for the takeoff.

Delayed takeoffs are common with space shuttle missions. The last shuttle to blast off, Endeavour, only did so in July after five scrubbed missions due to technical problems and bad weather.

The current planned 13-day mission is designed to transport new equipment and experiments to the International Space Station (ISS). Astronaut Nicole Stott is expected to relieve Timothy Kopra aboard the ISS, and three spacewalks are planned for the mission.

Discovery's crew for this mission includes six Americans and Swede Christer Fuglesang, flying for the European Space Agency.