Atlas/Cygnus pre-launch news conference

The most powerful version of United Launch Alliance’s Atlas 5 rocket lifted off from Cape Canaveral at 10:30 a.m. EDT (1430 GMT) today on a three-hour flight to deploy a U.S. Navy mobile communications satellite into orbit. Follow the mission in our live journal.

Flight controllers at NASA’s mission control center in Houston have completed the robotic swap out of a failed power distribution unit outside the International Space Station, clearing a hurdle ahead of Friday’s predawn launch from Cape Canaveral of a SpaceX supply ship.

The last flight of the single-core variant of United Launch Alliance’s Delta 4 rocket lifted off at 9:06 a.m. EDT (1306 GMT) Thursday from Cape Canaveral Air Force Station, Florida. The 207-foot-tall launcher carried a GPS navigation satellite into orbit for the U.S. Air Force.