I actually had a conversation with a NASA scientist about rigid airframes on Mars as a form of airborne rover. Turned out they wouldn't work either. Fucking Martian atmosphere.

OTOH, this *is* SF, so if we soften enough to allow for speculative things like gravity shields, or Mars specific magnetic levitation we can by damn have zeppelins on Mars. Or we could just ram enough comets into the planet to change it's atmosphere.