But if Musk’s rationale for keeping SpaceX private was to protect the Mars dream, is he abandoning this long-standing aim?

Not necessarily. It’s likely that Musk sees artificial intelligence as a key part of the Mars vision. Whether one believes the Optimus robot will become a viable product or not, Musk does. And he’s spoken about sending the robots to Mars to make the way smoother for the first human settlers.

Musk also believes that a larger and more financially robust SpaceX is necessary to undertake the settling of Mars. He understands that NASA will not pay for this, as the civil space agency is in the business of exploration and not settlement. For several years now, he has expressed that it will require about 1 million tons of supplies to be shipped to Mars to make a self-sustaining settlement. This is roughly 1,000 ships, and including refueling, at least 10,000 Starship launches. At $100 million per launch, that’s $1 trillion in launch costs alone.

Musk has frequently expressed a concern that there may be a limited window for settling Mars. Perhaps financial markets collapse. Perhaps there’s a worse pandemic. Perhaps a large asteroid hits the planet. Taking SpaceX public now is a bet that he can marshal the resources now, during his lifetime, to make Mars City One a reality. He is 54 years old.

The plan is not without risks, of course. If AI is something of a bubble, ten years from now, SpaceX may be sitting on hundreds of billions of dollars worth of satellites in space for which there is limited use. Maybe shareholders would rather SpaceX make them multimillionaires than make humans multiplanetary.

But Musk has never shied away from risks. So doubling down on his most successful asset in this moment is precisely what one would expect him to do.