The weather outlook for Friday morning's targeted launch of Discovery calls for a 70 percent chance of acceptable conditions at NASA's Kennedy Space Center in Florida. Liftoff would be at 12:22 a.m. Meteorologists will watch the conditions carefully throughout the countdown, with the greatest expected concern being for anvil clouds and thunderstorms within 20 nautical miles of the Shuttle Landing Facility. The mission management team will evaluate analysis of a fill-and-drain valve problem before Discovery's massive external tank is loaded with propellant. The valve issue developed during Tuesday's countdown and forced a postponement of the launch of the STS-128 mission.
