SpaceX's latest Starship prototype exploded just after an engine test Friday, erupting in a dramatic fireball at the spaceflight company's South Texas proving grounds. The Starship SN4 prototype exploded shortly before 2 p.m. CDT (3 p.m. EDT) at SpaceX's test facility near Boca Chica, Texas according to a video provided by the South Padre Island tourism site SPadre.com. The explosion occurred about a minute after a short test of its Raptor rocket engine, but it was unclear what caused the conflagration.