Mace could have survived by using the force to ease his drop. After falling down that far he probably regained his sense from the shock from palp somewhere in the air. Or maybe he landed in a cruiser or something. If Anakin could get his arms and legs cut off and burn near lava and still have some mechanical implants to get himself healed then so could mace. maybe he lived in exile like Yoda...............or maybe he's dead (which wouldn't have happened if palp and anakin didn't tag team on his ass.