A launch readiness review this morning concluded with a "go" to proceed toward a 7:38 p.m. Thursday launch of a next-generation military communications satellite from Cape Canaveral.
Known as WGS-4, its the fourth in the Defense Department's Wideband Global SATCOM series of high-capacity communications satellites.
Today, the Air Force confirmed it has ordered The Boeing Co. to begin working on a ninth WGS spacecraft, expected to cost $377 million. It will be purchased under a recently-announced international partnership with Canada, Denmark, Luxembourg, the Netherlands and New Zealand.
Air Force officials say plans for a 10th vehicle are also in the works.
Click here for more on Boeing's WGS spacecraft.
WGS-4 is set to rocket to orbit atop a United Launch Alliance Delta IV from Launch Complex 37 at Cape Canaveral Air Force Station. Thursday's launch window extends from 7:38 p.m. to 9:11 p.m. The weather forecast is excellent.