“This is about minimizing existential risk and having a sense of adventure. It’s about ensuring the light of consciousness is not extinguished, which I think is really important. … The probable lifespan of human civilization will be much greater if we are a multi-planetary species,” he said. “But the argument I find most compelling is it would be an incredible adventure. Life needs to be more than solving problems every day. You need to wake up and be inspired.”

The first Martians would be wealthy people, presumably the sort who possess both a pioneering spirit and a knack for construction. Musk hopes to lower the cost of a trip to Mars to roughly the median price of a house in the U.S., about $200,000, he said. The first settlers would build pressurized dome shelters on Mars, to protect them from Mars’s harsh climate and tenuous atmosphere. Larger domes would be built to harbor farms capable of feeding a population of one million. Eventually, SpaceX hopes to ship thousands of people per year to the Red Planet.

They would travel using the newly announced Interplanetary Transport System, which consists of a 40-foot-diameter rocket booster and 55-foot-diameter spaceship, codenamed the BFR and BFS, respectively (yes, those acronyms mean what you think they mean). Initially, Musk referred to his ship as the Mars Colonial Transporter, but earlier this month he said he was ditching that name, because the the rocket will be built to go beyond Mars. On Tuesday, he even invoked Europa, a moon of Jupiter that probably has an enormous ocean under its surface.

In the soaring promo video SpaceX unveiled Tuesday, the rocket lifts off and the ship heads to a “parking orbit” while the booster sails back to Earth, landing straight up on the same launchpad. There, it will pick up a new fuel tank and launch itself again, joining the spaceship in orbit and gassing it up for the trip to Mars. It would repeat this three to five times. Fueling the ship off Earth would dramatically lower costs, Musk said.

The ship resembles a multi-decker space shuttle, but without the iconic delta wings. Instead, once in orbit, it unfurls a pair of wing-like solar panels, like a butterfly emerging from a cocoon. The ship, made from carbon fiber, would accommodate at least 100 passengers and maybe up to 200, Musk said. It is gigantic, and could even have room for on-board eateries: “Pizza joints, you name it,” he said. It would have giant windows in its nose to ensure dazzling views.

“It’s got to be fun and exciting. It can’t feel cramped or boring,” he said. “It will be, like, really fun to go.”

While this all sounds like science fiction, Musk is already working on the engine that could make this happen. A few days ago, he tweeted the first glimpse of the Raptor, a powerful engine that can deliver about 500,000 pounds of thrust. It will use liquid methane for fuel, unlike both the Falcon 9 rockets and the space shuttle main engines. This is a strategic choice: While scientists are still hunting for signatures of methane at Mars, it can certainly be manufactured there, using ice and carbon dioxide from the Martian atmosphere.