Crews at Launch Complex 37 are preparing to roll back a mobile processing tower to unveil a 218-foot Delta IV for today's 7:38 p.m. launch attempt from Cape Canaveral Air Force Station.
On top of the United Launch Alliance rocket is a $464 million military satellite, the fourth in the Department of Defense's Wideband Global SATCOM series that will dramatically increase communications capacity for U.S. and allied troops.
The weather forecast remains almost perfect, with a 95 percent chance of favorable conditions during a launch window that extends to 9:11 p.m.
We'll have live countdown coverage here starting at 5:30 p.m., including a ULA launch Webcast that begins about 20 minutes before liftoff. We'll also send updates by text message -- sign up here.