At 5 p.m. EDT, the countdown entered a planned hold at the T-19 hour mark and will resume at 9 p.m.
Following a meeting of the Mission Management Team this morning, STS-135 countdown and weather updates were provided at prelaunch news conference. Panelists included Mike Moses, Mission Management Team chair and space shuttle launch integration manager, Mike Leinbach, shuttle launch director, and Kathy Winters, shuttle weather officer.
“We had a really smooth Mission Management Team meeting today,” said Moses. “The vehicle is in fantastic shape.” In regard to the launch-day weather forecast, he added, “Before we go load the propellants into the tank we’ll take a look at the weather and make sure it’s really a good day to try that, and so at that point we’ll be making a decision.”
“The countdown so far is going extremely well,” reported Leinbach. “We’re not tracking anything at all that would prevent an on-time liftoff Friday morning.”
“We have a tropical wave that’s out in the Caribbean,” explained Winters. “That wave is actually going to come into Florida along with a lot of tropical moisture that’s down to the south, and it’s all going to roll into Florida in the next couple of days.” Based on these conditions, Winters predicted an 80 percent chance of weather preventing tanking operations, with a 70 percent chance of it standing in the way of launch at 11:26 a.m. EDT on Friday. The forecast for the following days improves to 60 percent no-go on Saturday and 40 percent on Sunday.