public Vector<String> getAllVisibleLaunchersIds() {
		Vector<String> visibleIds = new Vector<>();
		
		for (EnemyLauncher el : enemyLauncherArr) {
			
			if (el.isAlive() && !el.getIsHidden()){
				visibleIds.add(el.getLauncherId());
			}
		}

		if (visibleIds.size() == 0)
			return null;

		return visibleIds;
	}