Watch live: Vice President Pence visits Kennedy Space Center

The Atlas 5 countdown leading up to Friday’s early morning liftoff from Cape Canaveral with Boeing’s Starliner crew capsule will be several hours longer than usual.

SpaceX’s first Falcon Heavy rocket is expected to roll out to pad 39A at NASA’s Kennedy Space Center for the first time next month for a hold-down firing of its 27 Merlin main engines, but the mega-rocket’s inaugural test launch will slip into January, officials confirmed Tuesday.

Launch companies and U.S. Space Force range officials at Cape Canaveral are reassessing long-standing weather rules, looking at beefing up rocket defenses against lightning, and considering strategies to prepare for two different launch windows on a given day to guard against weather delays, something SpaceX may demonstrate with a Falcon 9 launch early Thursday.