Photos: Delta 4 powers from launch pad on military mission

The United Launch Alliance Delta 4-Heavy rocket, standing 235 feet tall and weighing 1.6 million pounds fully fueled, unleashes 2.1 million pounds of thrust from the three RS-68A main engines at 1:51 p.m. EDT (1751 GMT) today to launch from Cape Canaveral on NROL-37.

The media briefing came after the agency formally pushed back the launch of the SpaceX Crew-9 mission to the International Space Station from mid-August to late-September.

In preparation for liftoff Dec. 18 aboard a United Launch Alliance Atlas 5 rocket, the powerful Internet-from-space broadcasting satellite called EchoStar 19 was encapsulated in the nose cone.