Video: SpaceX test-fires Falcon 9 rocket at pad 40 (members only)

SpaceX’s first Falcon Heavy rocket was loaded with propellants Saturday at Kennedy Space Center’s launch pad 39A, as engineers make progress preparing for a hold-down engine firing, and eventually liftoff of the huge commercial launcher.

A communications satellite developed in a public-private partnership between Luxembourg government and SES is set for launch Tuesday aboard a previously-flown SpaceX Falcon 9 booster from Cape Canaveral, ready for a 15-year mission beaming encrypted, jam-resistant signals for security and military forces across Europe, Africa and the Middle East.

United Launch Alliance is set to try again to launch a Delta 4-Heavy rocket and a classified U.S. government spy satellite Thursday after delays of more than three months caused by persistent issues with the mission’s launch pad.