SpaceX IPO could launch a new era, says first hire Tom Mueller

Tom Mueller’s view of SpaceX’s next act comes from the company’s very first days, when Elon Musk recruited him in 2002 after meeting him through an amateur rocket club. Mueller was already building a liquid-fueled engine in his garage, then in a friend’s warehouse, and the 80-pound design reportedly generated 13,000 pounds of thrust.

That early bet made Mueller SpaceX’s employee No. 1 and one of the central engineers behind the company’s propulsion program. He led work on the Merlin engine that still powers Falcon 9 today, and helped develop early engines for Falcon 1 and the Raptor program. SpaceX was founded in 2002, and by April that year Musk had already invited Mueller and other early hires to join the company.

Now Mueller says the company’s expected public offering could open a new phase for the space business. He called the IPO “life-changing” for thousands of employees and said Musk’s goal of making space cheaper through Falcon 9 “worked.” The offering is being described as the largest in history, with reporting placing SpaceX’s valuation at about $1.77 trillion, a scale that has also fueled speculation that Musk could become the world’s first trillionaire.

Mueller’s comments point to more than a windfall for SpaceX staff. They highlight how the center of gravity in space is moving beyond launch itself. Rockets still matter, but the faster-growing value is increasingly in satellites, orbital logistics and in-space mobility, where companies are building the infrastructure that comes after a vehicle leaves Earth.

Mueller has spent the last five years betting on that shift from the other side of the industry. He left SpaceX in 2020 and founded Impulse Space, where he is now chief executive and chief technology officer. In early June 2026, Impulse raised $500 million in a Series D round at a reported $4.26 billion valuation, lifting total funding above $1 billion as it expands its orbital-transfer business. The company plans to hire as many as 200 workers.

For Mueller, the trajectory is familiar: a small technical breakthrough, a bigger market built around it, and then an industry forced to reorganize around cheaper access and more complex services in orbit. SpaceX helped drive the first shift. Its IPO may help define the next one.