CNN  —  As Elon Musk returns his focus to his businesses, one of his most important companies just had another setback: A SpaceX Starship rocket exploded in an immense fireball Wednesday during a routine ground test. The explosion marks the fourth failure in a row for SpaceX’s Starship, all while Musk’s other companies and his personal brand struggle to recover after his foray into politics. Starship is supposed to help reach NASA’s goal of bringing American astronauts back to the moon by 2027: