Quote
A Saturday launch would occur at 1939 GMT (1539 EDT). An early weather forecast indicates a 40% chance of rain and a 30% chance of lightning on Saturday afternoon. "I'm hoping the weather's going to improve a little bit ... so we can get off on time," says astronaut Piers Sellers. If Discovery does not lift off on Saturday, its launch window shifts about 25 minutes earlier each day. This will give it a bigger chance of avoiding the afternoon thundershowers that are common in Florida in July. Discovery's window extends until 19 July.