After weathering tropical depression Ernesto at the launch pad, the shuttle Atlantis is set for launch from the Kennedy Space Center at 12:29 p.m. EDT on Wednesday, Sept. 6

Commander Brent Jett and his five crewmates will travel to the International Space Station to install a new 17-ton segment of the station's truss backbone, adding a new set of giant solar panels and batteries to the complex. Three spacewalks are planned.