40 percent chance of liftoff for space shuttle

Clouds of concern gathered for Thursday night's liftoff of the space shuttle Discovery as NASA downgraded launch chances to 40 percent due to weather. "The forecast has trended for the worse right now," said Kathy Winters, shuttle weather officer. An expected cloud ceiling at 3,000 feet (900 meters) was the biggest obstacle for getting Discovery off the ground at 9:35 p.m. EST (1435 GMT) Thursday.