Enlarge / What the view of Mars might look like from inside the Interplanetary Transport System. (credit: SpaceX)

Elon Musk finally did it. Fourteen years after founding SpaceX, and nine months after promising to reveal details about his plans to colonize Mars, the tech mogul made good on that promise Tuesday afternoon in Guadalajara, Mexico. Over the course of a 90-minute speech Musk, always a dreamer, shared his biggest and most ambitious dream with the world—how to colonize Mars and make humanity a multiplanetary species.

And what mighty ambitions they are. The Interplanetary Transport System he unveiled could carry 100 people at a time to Mars. Contrast that to the Apollo program, which carried just two astronauts at a time to the surface of the nearby Moon, and only for brief sojourns. Moreover, Musk’s rocket that would lift all of those people and propellant into orbit would be nearly four times as powerful than the mighty Saturn V booster. Musk envisions a self-sustaining Mars colony with at least a million residents by the end of the century.

Beyond this, what really stood out about Musk’s speech on Tuesday was the naked baring of his soul. Considering his mannerisms, passion, and the utter seriousness of his convictions, it felt at times like the man’s entire life had led him to that particular stage. It took courage to make the speech, to propose the greatest space adventure of all time. His ideas, his architecture for getting it done—they’re all out there now for anyone to criticize, second guess, and doubt.