What if some hypothetical new, all-seeing sub hunting breakthrough rendered today's super-stealthy nuclear missile submarines easy to locate and attack? How might America then regain the guaranteed second-strike deterrence needed to sustain global strategic stability against nuclear-armed adversary superpowers? The author suggests looking to the outer solar system, while thinking about another pressing defense need affecting Humanity: a reliable method for deflecting comets and asteroids that are on a collision course with Planet Earth, especially those known to be "flying rubble piles," or which move in weakly bound groups, or even sometimes have their own moons or rings.