Elon Musk isn’t planning a trip, he’s planning a new world. Musk believes humanity’s future depends on becoming multiplanetary not just visiting Mars, but building a city there that can survive on its own. His vision calls for 100,000 people and 1 million tons of cargo, delivered by fleets of SpaceX Starships over several decades. It sounds impossible now, but so did flight, space travel, and electric cars once. Big ideas always seem crazy, until they’re not. Musk’s Mars plan reminds us that pro