AST SpaceMobile has huge potential, but right now the exciting story here is really just potential.The latest exciting news out of AST SpaceMobile (ASTS -1.05%) is that it has delivered five satellites to Cape Canaveral. This is the first step toward actually offering the space-based cellular broadband network it is building. If it can get that system up and running, AST SpaceMobile could be a millionaire-maker stock. But don't get too excited; this is just one small step on the road to a full-fledged servi ...