diff --git a/gui/MainWindow.cpp b/gui/MainWindow.cpp
index d238c94..bc67e79 100644
--- a/gui/MainWindow.cpp
+++ b/gui/MainWindow.cpp
@@ -80,7 +80,7 @@ void MainWindow::on_testButton2_clicked()
    double initialVelocityX = initialVelocity * std::cos(initialAngle / 57.2958);
    double initialVelocityZ = initialVelocity * std::sin(initialAngle / 57.2958);
    Rocket rocket;
-   std::vector<double> initialState = {0.0, 0.0, 0.0, initialVelocityX, 0.0, initialVelocityZ};
+   std::vector<double> initialState = {0.0, 0.0, 0.0, initialVelocityX, 0.0, initialVelocityZ, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0};
    rocket.setInitialState(initialState);
    rocket.setMass(mass);
    rocket.setDragCoefficient(dragCoeff);
diff --git a/gui/MainWindow.ui b/gui/MainWindow.ui
index d95e704..d0d198d 100644
--- a/gui/MainWindow.ui
+++ b/gui/MainWindow.ui
@@ -105,42 +105,17 @@
          <x>260</x>
          <y>80</y>
          <width>161</width>
-         <height>120</height>
+         <height>151</height>
         </rect>
        </property>
        <layout class="QGridLayout" name="gridLayout">
-        <item row="0" column="0">
-         <widget class="QLabel" name="label">
-          <property name="text">
-           <string>Velocity</string>
-          </property>
-         </widget>
-        </item>
-        <item row="0" column="1">
-         <widget class="QLineEdit" name="initialVelocity">
-          <property name="text">
-           <string>50.0</string>
-          </property>
-         </widget>
-        </item>
-        <item row="1" column="0">
-         <widget class="QLabel" name="label_2">
-          <property name="text">
-           <string>Angle</string>
-          </property>
-         </widget>
-        </item>
         <item row="1" column="1">
          <widget class="QLineEdit" name="initialAngle">
           <property name="text">
            <string>90.0</string>
           </property>
-         </widget>
-        </item>
-        <item row="2" column="0">
-         <widget class="QLabel" name="label_3">
-          <property name="text">
-           <string>mass</string>
+          <property name="readOnly">
+           <bool>true</bool>
           </property>
          </widget>
         </item>
@@ -158,6 +133,20 @@
           </property>
          </widget>
         </item>
+        <item row="1" column="0">
+         <widget class="QLabel" name="label_2">
+          <property name="text">
+           <string>Angle</string>
+          </property>
+         </widget>
+        </item>
+        <item row="0" column="1">
+         <widget class="QLineEdit" name="initialVelocity">
+          <property name="text">
+           <string>50.0</string>
+          </property>
+         </widget>
+        </item>
         <item row="3" column="1">
          <widget class="QLineEdit" name="dragCoeff">
           <property name="text">
@@ -165,6 +154,34 @@
           </property>
          </widget>
         </item>
+        <item row="2" column="0">
+         <widget class="QLabel" name="label_3">
+          <property name="text">
+           <string>mass</string>
+          </property>
+         </widget>
+        </item>
+        <item row="0" column="0">
+         <widget class="QLabel" name="label">
+          <property name="text">
+           <string>Velocity</string>
+          </property>
+         </widget>
+        </item>
+        <item row="4" column="1">
+         <widget class="QLineEdit" name="timeStep">
+          <property name="text">
+           <string>0.01</string>
+          </property>
+         </widget>
+        </item>
+        <item row="4" column="0">
+         <widget class="QLabel" name="label_5">
+          <property name="text">
+           <string>Time Step</string>
+          </property>
+         </widget>
+        </item>
        </layout>
       </widget>
       <widget class="QWidget" name="gridLayoutWidget">
diff --git a/sim/Propagator.cpp b/sim/Propagator.cpp
index a2fcf23..7df4dbe 100644
--- a/sim/Propagator.cpp
+++ b/sim/Propagator.cpp
@@ -27,14 +27,21 @@ Propagator::Propagator(Rocket* r)
    // template types, and it derives from DESolver, so we can just reset the unique_ptr
    // and pass it a freshly allocated RK4Solver pointer
 
-   // The state vector has components of the form: (x, y, z, xdot, ydot, zdot)
+   // The state vector has components of the form:
+   // (x, y, z, xdot, ydot, zdot, pitch, yaw, roll, pitchRate, yawRate, rollRate)
    integrator.reset(new RK4Solver(
       /* dx/dt  */ [](double, const std::vector<double>& s) -> double {return s[3]; },
       /* dy/dt  */ [](double, const std::vector<double>& s) -> double {return s[4]; },
       /* dz/dt  */ [](double, const std::vector<double>& s) -> double {return s[5]; },
       /* dvx/dt */ [this](double, const std::vector<double>& ) -> double { return getForceX() / getMass(); },
       /* dvy/dt */ [this](double, const std::vector<double>& ) -> double { return getForceY() / getMass(); },
-      /* dvz/dt */ [this](double, const std::vector<double>& ) -> double { return getForceZ() / getMass(); }));
+      /* dvz/dt */ [this](double, const std::vector<double>& ) -> double { return getForceZ() / getMass(); },
+       /* dpitch/dt    */ [this](double, const std::vector<double>& s) -> double { return s[9]; },
+       /* dyaw/dt      */ [this](double, const std::vector<double>& s) -> double { return s[10]; },
+       /* droll/dt     */ [this](double, const std::vector<double>& s) -> double { return s[11]; },
+       /* dpitchRate/dt */ [this](double, const std::vector<double>& s) -> double { (getTorqueP() - s[7] * s[8] * (getIroll() - getIyaw())) / getIpitch(); },
+       /* dyawRate/dt   */ [this](double, const std::vector<double>& s) -> double { (getTorqueQ() - s[6] * s[9] * (getIpitch() - getIroll())) / getIyaw(); },
+      /* drollRate/dt   */ [this](double, const std::vector<double>& s) -> double { (getTorqueR() - s[6] * s[7] * (getIyaw() - getIpitch())) / getIroll(); }));
 
 
    integrator->setTimeStep(timeStep);
diff --git a/sim/Propagator.h b/sim/Propagator.h
index d275fd5..9022de7 100644
--- a/sim/Propagator.h
+++ b/sim/Propagator.h
@@ -48,6 +48,7 @@ public:
     void setSaveStats(bool s) { saveStates = s; }
 
 private:
+    double getMass();
     double getForceX();
     double getForceY();
     double getForceZ();
@@ -56,7 +57,9 @@ private:
     double getTorqueQ();
     double getTorqueR();
 
-   double getMass();
+    double getIpitch() { return 1.0; }
+    double getIyaw()   { return 1.0; }
+    double getIroll()  { return 1.0; }
 
 //private:
 
@@ -65,8 +68,8 @@ private:
    Rocket* rocket;
    QtRocket* qtrocket;
 
-   std::vector<double> currentState{0.0, 0.0, 0.0, 0.0, 0.0, 0.0};
-   std::vector<double> tempRes{0.0, 0.0, 0.0, 0.0, 0.0, 0.0};
+   std::vector<double> currentState{0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0};
+   std::vector<double> tempRes{0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0};
    bool saveStates{true};
    double currentTime{0.0};
    double timeStep{0.01};