Hoisting a 15,000-pound satellite atop an Atlas 5 rocket Wednesday, United Launch Alliance finished assembling its next space-bound booster for liftoff Aug. 31 in support of the U.S. Navy.

What began as a concept scribbled on a cocktail napkin in a Tucson bar 12 years ago — sending a spacecraft to an asteroid and retrieving a pristine sample to bring back to Earth for study — becomes reality Thursday with the launch of NASA’s OSIRIS-REx mission.

This video released by United Launch Alliance shows the Delta 4-Heavy rocket’s predawn liftoff Aug. 12 from the perspective of a downward-facing camera, capturing dazzling views of the fiery takeoff and the dramatic separation of the launcher’s two hydrogen-fueled boosters.