Every founder asks who will buy. Mars founders have to ask it in order — because the first customer of a new world is never the person who eventually lives there. Ask a room of space fans who the customer for Mars is and most will point at the end of the story: settlers, tourists, researchers in habitats, kids born under a pink sky. They are not wrong. They are just last. No new market in history has started with its final customer. Aviation did not start with holiday flights