Live coverage: Atlas 5 countdown and launch journal

A satellite to provide residential Internet services across the U.S. was hoisted aboard its United Launch Alliance Atlas 5 booster on Saturday, Dec. 10 in preparation for liftoff on Sunday, Dec. 18.

United Launch Alliance called off a test-firing of the company’s first flight-rated Vulcan Centaur rocket at Cape Canaveral Thursday to troubleshoot a problem with the booster’s engine ignition system.

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