The launch of the Delta IV Heavy is now set for 1:10:30 p.m. Pacific (4:10:30 p.m. EST; 2110:30 GMT): /– Delta Launch Report | Mission Status Center – Spaceflight Now /– ULA Webcast page /– LIVE: Delta IV Heavy set for debut West Coast launch with NRO L-49 | NASASpaceFlight.com
Update 4:22 pm EST: The launch seems to have gone well up through second stage separation and ignition. The view of the vehicle then stopped and the webcast signed off shortly after that. (This is a spysat launch after all.) The liftoff was quite a spectacle with transient flames climbing up around the vehicle and all the way to the top just as the engines ignited. Three LH2/LOX engines firing in parallel with identical flames also looked impressive.
Update 2: 6:00 pm EST: Though there is a DoD blackout on further details about the launch of the spysat, it was apparently a success: United Launch Alliance Launches First West Coast Delta IV Heavy Mission – ULA.
Here’s a video of the launch: