Q&A with Mike Laidley, vice president of Orbital ATK’s Next Generation Launch program (members only)

An official weather outlook issued by U.S. Air Force meteorologists Thursday calls for partly cloudy skies on Florida’s Space Coast for liftoff of a SpaceX Falcon 9 rocket just after sunrise Sunday with a clandestine payload for the U.S. government’s intelligence agencies.

After three frustrating days of weather delays, the United Launch Alliance Atlas 5 rocket blasted off from Cape Canaveral at 4:44 p.m. EST (2144 GMT) today to send Orbital ATK’s commercial Cygnus cargo freighter to the International Space Station.

Watch a 4K video replay of the first Falcon Heavy launch as viewed from the Kennedy Space Center Press Site around 3 miles from pad 39A.