An explosion has been captured at SpaceX ’s Starbase facility in Texas, where Elon Musk’s company is preparing to launch its Starship craft in a critical test of the world’s largest rocket.

SpaceX will test its giant rocket designed to one day take people to the moon and Mars on Friday after scrubbing an attempt on Thursday.

“For those who think this is simply another repeat test flight, the engineering changes under the rocket ‘hood’ are substantial,” Joseph Gonzalez, an associate professor of practice in aerospace engin...