diff --git a/mission/controller/acs/MultiplicativeKalmanFilter.cpp b/mission/controller/acs/MultiplicativeKalmanFilter.cpp
index 2ada8ab1..e752da39 100644
--- a/mission/controller/acs/MultiplicativeKalmanFilter.cpp
+++ b/mission/controller/acs/MultiplicativeKalmanFilter.cpp
@@ -1080,6 +1080,12 @@ ReturnValue_t MultiplicativeKalmanFilter::mekfEst(
 
   MatrixOperations<double>::add(*cov0, *cov1, *initialCovarianceMatrix, 6, 6);
 
+  if (not(MathOperations<double>::checkVectorIsFinite(propagatedQuaternion, 4)) ||
+      not(MathOperations<double>::checkMatrixIsFinite(initialQuaternion, 6, 6))) {
+    updateDataSetWithoutData(mekfData, MekfStatus::NOT_FINITE);
+    return MEKF_NOT_FINITE;
+  }
+
   updateDataSet(mekfData, MekfStatus::RUNNING, quatBJ, rotRateEst);
   return MEKF_RUNNING;
 }
diff --git a/mission/controller/acs/MultiplicativeKalmanFilter.h b/mission/controller/acs/MultiplicativeKalmanFilter.h
index ceb98339..fe749890 100644
--- a/mission/controller/acs/MultiplicativeKalmanFilter.h
+++ b/mission/controller/acs/MultiplicativeKalmanFilter.h
@@ -62,6 +62,7 @@ class MultiplicativeKalmanFilter {
     NO_MODEL_VECTORS = 2,
     NO_SUS_MGM_STR_DATA = 3,
     COVARIANCE_INVERSION_FAILED = 4,
+    NOT_FINITE = 5,
     INITIALIZED = 10,
     RUNNING = 11,
   };
@@ -74,8 +75,9 @@ class MultiplicativeKalmanFilter {
   static constexpr ReturnValue_t MEKF_NO_SUS_MGM_STR_DATA = returnvalue::makeCode(IF_MEKF_ID, 5);
   static constexpr ReturnValue_t MEKF_COVARIANCE_INVERSION_FAILED =
       returnvalue::makeCode(IF_MEKF_ID, 6);
-  static constexpr ReturnValue_t MEKF_INITIALIZED = returnvalue::makeCode(IF_MEKF_ID, 7);
-  static constexpr ReturnValue_t MEKF_RUNNING = returnvalue::makeCode(IF_MEKF_ID, 8);
+  static constexpr ReturnValue_t MEKF_NOT_FINITE = returnvalue::makeCode(IF_MEKF_ID, 7);
+  static constexpr ReturnValue_t MEKF_INITIALIZED = returnvalue::makeCode(IF_MEKF_ID, 8);
+  static constexpr ReturnValue_t MEKF_RUNNING = returnvalue::makeCode(IF_MEKF_ID, 9);
 
  private:
   /*Parameters*/