The clock keeps ticking towards Atlantis‘ Wednesday launch, with an 80% chance of good weather. NASA reports:

Ready to Fly
STS-115 Commander Brent Jett and Pilot Christopher Ferguson take to the skies in the specially configured Shuttle Training Aircraft to simulate landing the shuttle. Landing practice is part of pre-launch preparations. NASA PHOTO NO: KSC-06PD-2032At the launch readiness news conference on Monday afternoon, Wayne Hale, shuttle program manager, said that even though the tropical weather put them behind earlier in the week, thanks to hard work by the launch team, the vehicle is ready for liftoff and “we are looking forward to a really good mission.”

LeRoy Cain, launch integration manager, reported that after reviews by the mission management team, “At the end of the day we did our readiness poll to continue from here toward launch and we got a “go” from all the elements and we feel like we’re in very good shape.”

Shuttle Launch Director Mike Leinbach said the countdown is going smoothly and they are looking for a good, on-time liftoff on Wednesday.

U.S. Air Force First Lt. Kaleb Nordgren of the 45th Weather Squadron at Cape Canaveral Air Force Station provided an update on the prospects for launch-day weather issues. Conditions continue to look favorable, with only a 20 percent chance of a “no go” due to weather at the liftoff time of 12:29 p.m.

The countdown officially began at 8 a.m. Sunday, at the T-43 hour mark, which includes over 30 hours of built-in hold time prior to a targeted 12:29 p.m. launch on Wednesday. The launch time is the middle point in the launch window that extends for 10 minutes.

NASA mission managers agreed to make 3 launch attempts this week.