Stats: Atlas 5 history and backlog

United Launch Alliance called off the planned launch of an Atlas 5 rocket Wednesday at Cape Canaveral to resolve a problem with valves at the launch pad, while a SpaceX team a mile-and-a-half to the south readied a Falcon 9 rocket for liftoff Thursday evening with a GPS navigation satellite for the U.S. military.

A layer of fog intruding on Vandenberg Air Force Base in California kept nearby observers from seeing any sign of Saturday’s predawn launch of an Atlas 5 rocket carrying a robotic NASA probe to Mars. The only images of the Atlas 5’s fiery takeoff came from remote cameras placed at the launch pad, or from distant viewing points away from the poor visibility.

Loaded with supplies to keep the International Space Station’s crew fed, clothed and busy with new science projects, a Cygnus cargo vessel sped into orbit today atop an Atlas 5 rocket.