For more than a decade before SpaceX went public, CEO Elon Musk said it should not — for reasons that now feel keenly prescient.

Such a move, he warned, would make it too difficult to maintain a single-minded focus on the company’s audacious ultimate objective: colonizing Mars.

“Creating the technology needed to establish life on Mars is and always has been the fundamental goal of SpaceX,” Musk wrote in a 2013 email to SpaceX employees that also cautioned about the “irrational exuberance or depression” of the stock market.

“If being a public company diminishes that likelihood,” he wrote, “then we should not do so until Mars is secure.”

In the years since that email was sent, SpaceX has morphed from a rocketry underdog to the dominant force in the global space launch industry, returning astronaut flights to the United States after years of reliance on Russia and creating a multibillion-dollar business beaming internet from space.