Photos: News media images of Atlas 5 launch

SpaceX’s launch team loaded super-chilled liquid propellants into a two-stage Falcon 9 rocket Wednesday and fired the booster’s nine first stage engines at Cape Canaveral, marching toward liftoff Monday with a NASA observatory built to find planets around other stars in our galactic neighborhood.

United Launch Alliance teams rolled the Mobile Service Tower away from a Delta 4-Heavy rocket at Cape Canaveral’s Complex 37B launch pad Wednesday in preparation for liftoff on a national security mission.

Launching for the 200th time and loaded with one of its heaviest cargoes ever, the Atlas-Centaur rocket flexed its muscle and sped away from Cape Canaveral on Tuesday night with a U.S. Navy satellite for mobile communications to the military and White House.