Photos: New GPS navigation satellite powered from Earth

A United Launch Atlas 5 rocket is set to launch the U.S. Air Force’s fourth Advanced Extremely High Frequency communications satellite from Cape Canaveral. This timeline shows the major mission events planned over a three-and-a-half-hour flight to an optimized geostationary transfer orbit.

A United Launch Alliance Delta 4 rocket lifted off Wednesday at 2:36 p.m. EDT (1836 GMT) from Cape Canaveral on a mission to place into orbit a fresh satellite for the Global Positioning System.

Two companies — U.S. aerospace giant Lockheed Martin and British start-up Orbex — seeking to carve out a share of the burgeoning small satellite launch market plan to fly their rockets from a remote site on the northern shore of Scotland, British government and industry officials announced Monday.