SpaceX’s first employee, Tom Mueller, thinks the historic IPO is just the beginning

The guy who built Space X’s engines has thoughts on its IPO. Tom Mueller was employee No. 1 at Space X. He built the engines behind the Falcon 9 rocket that rewrote the economics of getting to orbit. Now, he runs Impulse Space, valued at $4.26 billion, which designs and manufactures space vehicles that move satellites from one orbit to another. So, when Space X filed for its IPO, Mueller had more skin in the game than most. His reaction when the S-1 dropped? “Finally.” For years, Musk was vocally hostile to the idea of taking SpaceX public. He’d lived through the whiplash of Tesla’s public market journey and made no secret of his preference for the freedom of staying private. But SpaceX’s ambitions have outgrown its balance sheet. The company is targeting 555.6 million shares at $135 each—a $75 billion raise that would be the largest IPO in history. At that price, the company is valued at roughly $1.75 trillion. Mueller told me that valuation “seems incredible”—and he meant it somewhat literally. SpaceX posted $18.67 billion in 2025 revenue with a $4.9 billion net loss, driven by nearly doubled capital expenditures of $20.7 billion, much of it going into AI development. “You’ve got to understand what Elon’s selling,” he told me. The valuation is actually a bet on compute and data centers moving to space and that Musk has the vertically-integrated stack to make that happen: Musk has cheap rockets to get hardware into orbit, Starlink has already proven you can run serious computing power in space (the satellite internet business alone generated $11.39 billion in 2025 revenue). And between xAI’s Grok, Tesla’s robotics, and X, he’s sitting on more data to train AI models than almost anyone on the planet. “He has all the pieces,” Mueller said. Doubting that thesis, Mueller explained, requires you to ignore SpaceX’s entire track record: Falcon 1, Falcon 9, crewed missions to