void Start()
 {
     UIManager.Instance.SetupControlPanel(rocketMaterials, rocketFuels, maxFuel);
     state = GameState.Tutorial;
     UIManager.Instance.OnTutorial();
     // Refresh the HUD and show the tutorial screen.
     UIManager.Instance.ShowHUD(false);
     UIManager.Instance.ShowScreen("Tutorial");
     rocket.Reset();
 }