Photos: Delta 4-Heavy with Orion on eve of launch

On its second flight, SpaceX’s mammoth Falcon Heavy rocket hurled an Arabsat communications satellite the size of a school bus nearly one-quarter the way to the moon Thursday, days after NASA’s administrator identified the privately-developed rocket as a backup to the agency’s behind-schedule Space Launch System for sending astronauts back to the lunar surface.

A countdown dress rehearsal and rocket fueling exercise was completed at Cape Canaveral for next month’s launch of NASA’s Orion crew module atop a United Launch Alliance Delta 4-Heavy booster.

This video recaps the Orion spacecraft and its Delta 4-Heavy rocket preparations for launch on the Exploration Flight Test No. 1.