Watch a time-lapse of the Crew Dragon access arm installation (members only)

SpaceX had to swap out the first stage booster used during the previous attempt and replace it with another for this mission. Liftoff from pad 40 happened at 12 a.m. EST (0500 UTC) on Sunday, Dec. 29.

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.

Follow the key events of the Falcon 9 rocket’s ascent into space from Cape Canaveral with the ABS 2A and Eutelsat 117 West B communications satellites.