The United Launch Alliance Atlas V rocket stands at Launch Complex 41 on Cape Canaveral Air Force Station in Florida during a "wet dress rehearsal." The test called for the launch vehicle to be fully loaded with propellants and put through a countdown procedure, ending just before the T-0 mark. The spacecraft is undergoing prelaunch processing activities in the Kennedy Space Center's Payload Hazardous Servicing Facility and was not atop the rocket for this rehearsal. The Atlas V rocket is slated to launch the Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft on a journey to the Red Planet on Nov. 18. The spacecraft is undergoing prelaunch processing activities in the Kennedy Space Center's Payload Hazardous Servicing Facility and was not atop the rocket for this rehearsal. Positioned in an orbit above the Red Planet, MAVEN will study the upper atmosphere of Mars in unprecedented detail.