Index: /issm/trunk-jpl/src/mobile/android/ISSM_APP/AndroidManifest.xml
===================================================================
--- /issm/trunk-jpl/src/mobile/android/ISSM_APP/AndroidManifest.xml	(revision 14520)
+++ /issm/trunk-jpl/src/mobile/android/ISSM_APP/AndroidManifest.xml	(revision 14521)
@@ -14,5 +14,6 @@
         <activity android:name="gov.nasa.jpl.issm.ISSMAPP" 
             	  android:screenOrientation="portrait"
-            	  android:label="@string/title_activity_issm" >
+            	  android:label="@string/title_activity_issm"
+            	  android:noHistory="true" >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
Index: /issm/trunk-jpl/src/mobile/android/ISSM_APP/bin/AndroidManifest.xml
===================================================================
--- /issm/trunk-jpl/src/mobile/android/ISSM_APP/bin/AndroidManifest.xml	(revision 14520)
+++ /issm/trunk-jpl/src/mobile/android/ISSM_APP/bin/AndroidManifest.xml	(revision 14521)
@@ -14,5 +14,6 @@
         <activity android:name="gov.nasa.jpl.issm.ISSMAPP" 
             	  android:screenOrientation="portrait"
-            	  android:label="@string/title_activity_issm" >
+            	  android:label="@string/title_activity_issm"
+            	  android:noHistory="true" >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
Index: /issm/trunk-jpl/src/mobile/android/ISSM_APP/res/layout/issmcore.xml
===================================================================
--- /issm/trunk-jpl/src/mobile/android/ISSM_APP/res/layout/issmcore.xml	(revision 14520)
+++ /issm/trunk-jpl/src/mobile/android/ISSM_APP/res/layout/issmcore.xml	(revision 14521)
@@ -20,5 +20,5 @@
         android:layout_height="wrap_content"
         android:layout_above="@+id/play"
-        android:layout_below="@+id/back"
+        android:layout_below="@+id/spinner"
         android:layout_marginBottom="12dp" >
     </FrameLayout>
@@ -33,5 +33,5 @@
         android:layout_marginBottom="18dp"
         android:background="@drawable/custom_button"
-        android:text="Solve" /> -->
+        android:text="Solve" /> 
 
     <Button
@@ -41,5 +41,5 @@
         android:layout_alignParentLeft="true"
         android:layout_alignParentTop="true"
-        android:background="@drawable/back_button"/>
+        android:background="@drawable/back_button"/> -->
     
     <Spinner
Index: /issm/trunk-jpl/src/mobile/android/ISSM_APP/src/gov/nasa/jpl/issm/ISSM.java
===================================================================
--- /issm/trunk-jpl/src/mobile/android/ISSM_APP/src/gov/nasa/jpl/issm/ISSM.java	(revision 14520)
+++ /issm/trunk-jpl/src/mobile/android/ISSM_APP/src/gov/nasa/jpl/issm/ISSM.java	(revision 14521)
@@ -11,4 +11,5 @@
 import android.util.DisplayMetrics;
 import android.view.Gravity;
+import android.view.KeyEvent;
 import android.view.Menu;
 import android.view.MenuInflater;
@@ -52,4 +53,5 @@
 	private ImageView defaultMap;
 	private Spinner spinner;
+	private boolean onSimulationScreen = false;
 	//------------------------------------------------------------------------------------------------    
     @Override
@@ -77,6 +79,6 @@
         //Button solve = (Button) super.findViewById(R.id.solve);
         //solve.setOnClickListener(this);
-        Button back = (Button) super.findViewById(R.id.back);
-        back.setOnClickListener(this);
+        //Button back = (Button) super.findViewById(R.id.back);
+        //back.setOnClickListener(this);
         Button play = (Button) super.findViewById(R.id.play);
         play.setOnClickListener(this);
@@ -145,4 +147,19 @@
     	return true;
     }
+//---------------------------------------------------------------------------------
+    @Override
+    public boolean onKeyDown(int keyCode, KeyEvent event)  {
+        if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0 && onSimulationScreen) {
+        	 frame.removeView(mGLView);
+   		 	 viewflipper.setInAnimation(inFromLeftAnimation());
+	         viewflipper.setOutAnimation(outToRightAnimation());
+	         viewflipper.showPrevious(); 
+	         onSimulationScreen = false;
+            return true;
+        }
+        // return to menu screen
+        finish();
+        return super.onKeyDown(keyCode, event);
+    } 
 //---------------------------------------------------------------------------------   
     public void onClick(View view) 
@@ -157,4 +174,5 @@
 		        viewflipper.showNext();
 		        defaultMap.setVisibility(View.VISIBLE);
+		        onSimulationScreen = true;
 		        //create FemModel in native code and return the size of the model
 		        this.createModel();
@@ -168,9 +186,10 @@
 		        viewflipper.showNext();
 		        defaultMap.setVisibility(View.VISIBLE);
+		        onSimulationScreen = true;
 		        //create FemModel in native code and return the size of the model
 		        this.createModel();
 		        break;
 			}
-	    	case R.id.back:
+	    	/*case R.id.back:
 	    	{
 	    		 frame.removeView(mGLView);
@@ -179,5 +198,5 @@
 		         viewflipper.showPrevious(); 
 		         break;
-	    	}
+	    	}*/
     		/*case R.id.solve:
     		{