[douglas]

I'm pretty sure a strategy set to not fire on planets would work as long as Don't Get Hurt isn't involved. If no valid targets for the strategy are present, however, and the ship happens to wander into (or start in) weapon platform range of the planet it'll just randomly meander about at 1 square per combat turn in random directions while the planet shoots at it until its weapons are gone and the hardcoded "Don't Get Hurt unless ramming" provision for unarmed ships comes into play.