It’s not clear how much the rocket would cost to develop, or where that money would come from, or when precisely it would fly.

It’s not even certain that even after the best efforts of Elon Musk’s hard-charging space company that the massive 400-foot rocket he imagines would get people to Mars and save the species should humanity face extinction will ever fly. And if it did, Musk noted during a news conference Monday night, it would be a perilous journey that could end in failure.

“It’s dangerous, to be clear,” he said.

So when Musk introduced a Japanese billionaire, who hopes to take several artists along with him on a trip around the moon on SpaceX’s new rocket, the only thing that’s certain is that nothing is guaranteed. Especially at a time when Musk is facing extraordinary pressures at the moment on Earth.

The Securities and Exchange Commission is investigating Musk’s claim that he had the “funding secured” to take Tesla, his electric car company, private. He has ratted investors with his erratic behavior, smoking marijuana on a live broadcast. And on the day he announced his moonshot, he was sued for defamation by the Thai-cave rescuer he called a “child rapist.”

And he has often struggled to meet the overly ambitious timelines he has set for his companies. Earlier in the day Monday, Gwynne Shotwell, SpaceX’s president and chief operating officer, noted how his dreams so often struggle to break the bonds of what’s possible.

“Everything we’ve ever done has sounded crazy to people that love us and people that don’t love us so much,” she said at an Air Force conference.

That includes the timeline Musk has set for the moon mission. Yusaku Maezawa, the Japanese billionaire entrepreneur who has signed up for it, said he hoped it would be 2023. But Musk hedged, saying, “We’re definitely not sure.” The 2023 date could be possible, he said, if everything went right. But then he noted that it seldom does.

“You have to set some kind of a date that’s kind of like the things-go-right date,” Musk said. “Then, of course, we have reality, and things do not go right in reality. Usually there are setbacks and issues.”

The cost of the rocket was also unknown. “It’s definitely hard to say what the development cost is,” Musk said. He said he thought it would be “roughly $5 billion,” but then said that was a “guess.”

And it was also unclear where the money would come from to pay for that amount — if in fact that’s what it ends up costing.

“Funding BFR is definitely a key question,” Musk conceded. “We need to seek every possible means of funding.” He cited the company’s lucrative contracts with NASA to fly cargo and eventually crews to the International Space Station. SpaceX also hopes to put up a constellation of satellites in orbit that would allow everyone on Earth to connect to the Internet. While Musk said that would be “a key source of revenue,” it’s not clear the company is going to be able to achieve that goal.

Finally, the rocket ever getting off the launchpad is not guaranteed.

“There’s so many uncertainties. This is a ridiculously big rocket, it’s got so much advanced technology. It’s not 100 percent that we succeed in getting this to flight,” Musk said. “I think it’s pretty likely, but it’s not certain. But we’ll do everything humanly possible to bring it to flight as fast as we can and as safely as we can.”

Then again, as Musk pointed out at the beginning of his talk, SpaceX itself is an improbable success story. No one thought an eccentric tech entrepreneur with no experience in space could build a rocket capable of getting to orbit. And now, the company has 7,000 employees, a backlog of commercial satellite launches, billions of dollars in contracts with NASA.

He’s said he was starry-eyed and naive when he started the company, and to a degree remains that way today, hoping he can somehow build a rocket that could get people to the moon.

That vision of the future, no matter how realistic, has him “super fired up,” he said. “It’d be great if there were regularly scheduled flights to the moon.”

That dream is clearly a source of solace, something that he said has “done a lot to restore my faith in humanity.”

But here, in the present day, Musk is under extreme duress. Tesla is struggling to meet production goals. And recently he said that it has gone from “production hell to delivery logistics hell.” Meanwhile, the defamation lawsuit could continue to dog him and highlight what some investors saw as an unnecessary and self-inflicted controversy.

He recently told the New York Times his health was suffering as a result of an “excruciating” year.

None of that came up Monday evening, a night dedicated to the promise of the work artists inspired by space travel would produce. Musk seemed unbothered by the chaos swirling around him, content to look forward. The present may be perilous, but out in the distance, the future holds something great. He was sure of it.

“I can’t wait,” he said.

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