The cryogenic propellant tanks on the United Launch Alliance Atlas V booster stage and Centaur upper stage are loaded now as we move toward a liftoff time of 5:33 p.m. EST from Cape Canaveral Air Force Station in Florida, adjacent to NASA’s Kennedy Space Center. Pumps have slowed to “topping mode.” The booster’s RD-180 engine uses RP-1 fuel and liquid oxygen to generate about 933,000 pounds of thrust. The Centaur stage burns liquid hydrogen and liquid oxygen to place the Orbital ATK enhanced Cygnus spacecraft and its 7,383 pounds of cargo into its initial orbit to get to the International Space Station. The launch window is 30 minutes today.