|Four minutes during NASA's OCO-2 satellite launch from Vandenberg AFB, California|
+Philip Plait (The Bad Astronomer) goes into some detail on the satellite in his blog post NASA Launches a New Eye on Carbon Dioxide, so I'll stick to the photographic detail in the following sequence of photos matched to their corresponding events in the launch timeline.
The launch ignition sequence will begin at T-minus 2 seconds when a launch team member triggers the engine start switch. The process begins with ignition of the two vernier thrusters and first stage main engine start. The three ground-lit solid rocket motors then light at T-0 for liftoff.
T+plus 36 seconds. Delta has broken the sound barrier, rapidly accelerating on the power of its first stage main engine and the three ground-lit strap-on solid-fuel boosters.
Here's the whole sequence put together in a time-lapse video covering 3 hours prior to 1 hour after launch:
If night photography looks like something you'd like to master, I'm scheduling a night photography session at California's Bodie State Historic Park on July 25: http://www.jeffsullivanphotography.com/blog/bodie-night-photography-workshops/