This is the ascent 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 11:30 a.m. local time (2:30 p.m. EDT; 1830 GMT).
T+0:04:09.1: Stage Separation
The Common Core Booster first stage of the Atlas 5 rocket separates from the Centaur upper stage. Over the next few seconds, the Centaur engine liquid hydrogen and liquid oxygen systems are readied for ignition.
T+0:04:19.0: Centaur Ignition No. 1
The Centaur RL10C-1 engine ignites for the longer of the two upper stage firings. This burn will inject the Centaur stage and WorldView 4 spacecraft into polar orbit.
T+2:11:45.9: Cubesat Separation
Seven tiny Cubesats being launched through a National Reconnaissance Office-sponsored rideshare, called the ENTERPRISE mission, are ejected from carriers mounted near the RL10 engine over a period of 14 minutes. The Centaur then executes another burn to escape Earth and enter solar orbit.
See earlier WorldView 4 coverage.
Our Atlas archive.
from Spaceflight Now ift.tt/2cdCcYh