The Thai cave rescue is over, with all 12 boys and their coach safely above ground. Elon Musk's miniature submarine clearly arrived too late. However, it's now clear that it wouldn't have seen use regardless. In the last few hours of the operation, joint command center lead Narongsak Ostanakorn told Musk that his tech was "good and sophisticated," but that it was "not practical" for the rescue. While officials haven't provided detailed reasoning, a look at the logistics of the rescue might explain why.