Live coverage: Atlas 5 countdown and launch journal

The 377th Delta rocket begins its journey to space carrying a military communications satellite funded by Canada, Denmark, the Netherlands, Luxembourg and New Zealand in a deal that gives the allies access to the U.S. military’s worldwide Wideband Global SATCOM system.

United Launch Alliance engineers have resolved the problem that triggered an abort of a planned Delta 4-Heavy rocket launch Sept. 30, but the company said Friday it is continuing to evaluate a concern with the launch pad swing arm retraction system at Cape Canaveral. ULA said the Delta 4-Heavy’s mission to launch a classified National Reconnaissance Office spy satellite will be postponed beyond next week.

The Atlas 5 rocket blasts off from Vandenberg Air Force Base in California for its late-night ascent to deploy the NROL-42 payload for the National Reconnaissance Office.