diff --git a/mission/controller/acs/FusedRotationEstimation.cpp b/mission/controller/acs/FusedRotationEstimation.cpp
index 501d1913..bd84cb82 100644
--- a/mission/controller/acs/FusedRotationEstimation.cpp
+++ b/mission/controller/acs/FusedRotationEstimation.cpp
@@ -9,9 +9,9 @@ void FusedRotationEstimation::estimateFusedRotationRateSafe(
     acsctrl::GyrDataProcessed *gyrDataProcessed, acsctrl::FusedRotRateData *fusedRotRateData) {
   if ((not mgmDataProcessed->mgmVecTot.isValid()) or
       (not susDataProcessed->susVecTot.isValid() and
-       VectorOperations<double>::norm(fusedRotRateData->rotRateTotal.value, 3)) == 0 or
-      ((VectorOperations<double>::norm(susDataProcessed->susVecTotDerivative.value, 3) == 0 and
-        VectorOperations<double>::norm(mgmDataProcessed->mgmVecTotDerivative.value, 3) == 0))) {
+       not fusedRotRateData->rotRateTotal.isValid()) or
+      (not susDataProcessed->susVecTotDerivative.isValid() and
+       not mgmDataProcessed->mgmVecTotDerivative.isValid())) {
     {
       PoolReadGuard pg(fusedRotRateData);
       std::memcpy(fusedRotRateData->rotRateOrthogonal.value, ZERO_VEC, 3 * sizeof(double));