Delta 4

Video: Liftoff of Delta 4 rocket and WGS 9 satellite

The United Launch Alliance Delta 4 rocket, standing 217 feet tall and weighing 900,000 pounds, unleashes 1.8 million pounds of thrust from its main engine and four side-mounted boosters at 8:18 p.m. EDT Saturday (0018 GMT Sunday) to launch the ninth Wideband Global SATCOM satellite for U.S. military and allied communications.

Delta 4

Photos: Launch pad gantry retracted from Delta 4 rocket

The 330-foot-tall mobile service tower is rolled away from the United Launch Alliance Delta 4 rocket at Cape Canaveral’s pad 37B in the hours before the scheduled liftoff. The 9-million-pound gantry was retracted the length of a football field in preparation for launch of the Air Force’s WGS 9 communications satellite into Earth orbit.