SOUTH PADRE ISLAND, Texas—It began with a bang, as big things often do.

On Thursday morning, with clearing skies overhead, SpaceX’s Starship rocket slowly began to climb away from its launch pad. Fully laden with about 5,000 metric tons of liquid oxygen and methane propellant, the largest rocket ever built needed about 10 seconds to begin clearing the launch pad.

From a nearby vantage point, the rocket rumbled and the smoke billowed outward—but it seemed like an eternity before Starship poked its head above the smoke and dust. And then it climbed skyward, a brilliant silvery and fiery streak in the sky.