No customer has ever bought a ticket to Mars. So who is writing the checks that are building the road there? Follow the capital stack. Every Mars headline is secretly a finance story. A rocket rises, and underneath it sit four different kinds of money, stacked in layers, each with its own motive. Understand the stack and you understand why Mars is moving now — after decades of paper studies — and who gets paid along the way. This is the pillar piece for The Money: the map we