diff --git a/include/ale/States.h b/include/ale/States.h
index c4e5e818ba154a570c5aceae7b675949c1fd72e8..ffcf5b53ae93ff727ad6ea302cf294311637674f 100644
--- a/include/ale/States.h
+++ b/include/ale/States.h
@@ -1,6 +1,8 @@
 #ifndef ALE_STATES_H
 #define ALE_STATES_H
 
+#include <cmath>
+#include <limits>
 #include <vector>
 #include <stdexcept>
 
@@ -23,8 +25,17 @@ namespace ale {
       velocity = {vec[3], vec[4], vec[5]};
     };
 
+    State(Vec3d position) : position(position) {
+      velocity = {std::numeric_limits<double>::quiet_NaN(),
+                  std::numeric_limits<double>::quiet_NaN(),
+                  std::numeric_limits<double>::quiet_NaN()};
+    };
     State(Vec3d position, Vec3d velocity) : position(position), velocity(velocity) {};
     State() {};
+
+    bool hasVelocity() const {
+      return !(std::isnan(velocity.x) || std::isnan(velocity.y) || std::isnan(velocity.z));
+    }
   };
 
   class States {
diff --git a/src/States.cpp b/src/States.cpp
index a059780f995c052e55ab978f828b1536b34471cb..f5b6e5ad79e30b4bca419a5c12ceda897b243b55 100644
--- a/src/States.cpp
+++ b/src/States.cpp
@@ -23,9 +23,8 @@ namespace ale {
       throw std::invalid_argument("Length of times must match number of positions");
     }
 
-    Vec3d velocities = {0.0, 0.0, 0.0};
     for (Vec3d position : positions) {
-      m_states.push_back(State(position, velocities));
+      m_states.push_back(State(position));
     }
   }
 
@@ -93,10 +92,9 @@ namespace ale {
 
 
   bool States::hasVelocity() const {
-    std::vector<Vec3d> velocities = getVelocities();
-    bool allZero = std::all_of(velocities.begin(), velocities.end(), [](Vec3d vec)
-                               { return vec.x==0.0 && vec.y==0.0 && vec.z==0.0; });
-    return !allZero;
+    bool allVelocity = std::all_of(m_states.begin(), m_states.end(), [](State vec)
+                                   { return vec.hasVelocity(); });
+    return allVelocity;
   }
 
 
diff --git a/tests/ctests/IsdTests.cpp b/tests/ctests/IsdTests.cpp
index b0dee7be06265e4d8641e147ec0bc42ec67d5a0f..5c001bf567eda5ab9bbdbec423afc6f644d7e082 100644
--- a/tests/ctests/IsdTests.cpp
+++ b/tests/ctests/IsdTests.cpp
@@ -158,7 +158,6 @@ TEST(Isd, GetSunPositions) {
 
   ale::States sunPosObj = ale::getSunPosition(jsunpos);
   std::vector<ale::Vec3d> position = sunPosObj.getPositions();
-  std::vector<ale::Vec3d> velocity = sunPosObj.getVelocities();
 
   ASSERT_EQ(sunPosObj.getStates().size(), 1);
   ASSERT_EQ(sunPosObj.getReferenceFrame(), 2);
@@ -168,14 +167,12 @@ TEST(Isd, GetSunPositions) {
   ASSERT_EQ(position[0].y, 12);
   ASSERT_EQ(position[0].z, 13);
 
-  ASSERT_EQ(velocity[0].x, 0);
-  ASSERT_EQ(velocity[0].y, 0);
-  ASSERT_EQ(velocity[0].z, 0);
+  ASSERT_FALSE(sunPosObj.hasVelocity());
 
   jsunpos["sun_position"]["velocities"] = {{1, 2, 3}};
 
   sunPosObj = ale::getSunPosition(jsunpos);
-  velocity = sunPosObj.getVelocities();
+  std::vector<ale::Vec3d> velocity = sunPosObj.getVelocities();
 
   ASSERT_EQ(velocity[0].x, 1);
   ASSERT_EQ(velocity[0].y, 2);
@@ -206,7 +203,6 @@ TEST(Isd, GetInstrumentPositions) {
 
   ale::States instPosObj = ale::getInstrumentPosition(jinstpos);
   std::vector<ale::Vec3d> positions = instPosObj.getPositions();
-  std::vector<ale::Vec3d> velocities = instPosObj.getVelocities();
 
   ASSERT_EQ(instPosObj.getStates().size(), 2);
   ASSERT_EQ(instPosObj.getReferenceFrame(), 4);
@@ -222,14 +218,12 @@ TEST(Isd, GetInstrumentPositions) {
   ASSERT_EQ(positions[1].y, 12);
   ASSERT_EQ(positions[1].z, 13);
 
-  ASSERT_EQ(velocities[0].x, 0);
-  ASSERT_EQ(velocities[0].y, 0);
-  ASSERT_EQ(velocities[0].z, 0);
+  ASSERT_FALSE(instPosObj.hasVelocity());
 
   jinstpos["instrument_position"]["velocities"] = {{0, 1, 2}, {3, 4, 5}};
 
   instPosObj = ale::getInstrumentPosition(jinstpos);
-  velocities = instPosObj.getVelocities();
+  std::vector<ale::Vec3d> velocities = instPosObj.getVelocities();
 
   ASSERT_EQ(velocities[0].x, 0);
   ASSERT_EQ(velocities[0].y, 1);
diff --git a/tests/ctests/StatesTests.cpp b/tests/ctests/StatesTests.cpp
index 25ca53981fb13093ca99a3809935ad3578dced56..59a616133a52d4c7fb65786c64877c34edd6c7a2 100644
--- a/tests/ctests/StatesTests.cpp
+++ b/tests/ctests/StatesTests.cpp
@@ -29,15 +29,10 @@ TEST(StatesTest, ConstructorPositionNoVelocity) {
   EXPECT_NEAR(states[0].position.x, 4.0, 1e-10);
   EXPECT_NEAR(states[0].position.y, 1.0, 1e-10);
   EXPECT_NEAR(states[0].position.z, 4.0, 1e-10);
-  EXPECT_NEAR(states[0].velocity.x, 0.0, 1e-10);
-  EXPECT_NEAR(states[0].velocity.y, 0.0, 1e-10);
-  EXPECT_NEAR(states[0].velocity.z, 0.0, 1e-10);
   EXPECT_NEAR(states[3].position.x, 7.0, 1e-10);
   EXPECT_NEAR(states[3].position.y, 4.0, 1e-10);
   EXPECT_NEAR(states[3].position.z, 1.0, 1e-10);
-  EXPECT_NEAR(states[3].velocity.x, 0.0, 1e-10);
-  EXPECT_NEAR(states[3].velocity.y, 0.0, 1e-10);
-  EXPECT_NEAR(states[3].velocity.z, 0.0, 1e-10);
+  EXPECT_FALSE(noVelocityState.hasVelocity());
 }
 
 TEST(StatesTest, ConstructorPositionAndVelocity) {