From rockets to brain implants, Elon Musk – the world's first trillionaire – commands a sprawling business empire spanning electric vehicles, satellite internet, artificial intelligence, social media, tunnel construction, and neuroscience, all anchored by SpaceX's record-breaking $2.1 trillion IPO this week. Elon Musk Founder CEO Chairman and Chief Engineer of SpaceX on IPO day (Reuters image) Elon Musk becomes first trillionaire after SpaceX's record IPOSpaceX, xAI, Starlink, X, Tesla, Neuralink, Boring Co. under MuskStarlink generated $4.4B income, aiding SpaceX's financesDid our AI summary help? Elon Musk, the man who became history's first trillionaire doesn't just run one company — he…