Photos: More Delta 4 launch shots

An Ariane 5 rocket emerged from its vertical assembly building Monday and rolled along dual rail tracks for a 1.7-mile (2.7-kilometer) journey to its launch pad at the Guiana Space Center on the northern coastline of South America, moving into position for blastoff Wednesday with four Galileo navigation satellites.

Virgin Orbit could attempt its first orbital test launch later this month over the Pacific Ocean southwest of Los Angeles, capping a development program for an air-launched small satellite carrier that began in earnest eight years ago.

Plans to launch a Navy communications satellite aboard an Atlas 5 rocket early Monday have been interrupted by Tropical Storm Erika, an unpredictable cyclone with its sights on Florida.