Last flight of the Titan

SpaceX’s launch team fueled up a Falcon 9 rocket on a California launch pad Thursday, fired the booster’s nine Merlin engines, and passed a key preflight test for the first time since a Falcon 9 exploded during a similar practice countdown in September.

This is the launch timeline to be followed by the Atlas 5 rocket’s ascent into orbit from Vandenberg Air Force Base in California with the commercial WorldView 4 Earth-imaging satellite for DigitalGlobe. Launch is scheduled for Friday at 10:30 a.m. local time (1:30 p.m. EST; 1830 GMT).

A collection of pad photos from the United Launch Alliance Delta 4 rocket flight to deploy the NROL-45 spy satellite payload for the U.S. National Reconnaissance Office.