diff --git a/mission/controller/acs/FusedRotationEstimation.cpp b/mission/controller/acs/FusedRotationEstimation.cpp
index 20f12d05..6653f4d1 100644
--- a/mission/controller/acs/FusedRotationEstimation.cpp
+++ b/mission/controller/acs/FusedRotationEstimation.cpp
@@ -22,6 +22,10 @@ void FusedRotationEstimation::estimateFusedRotationRateSafe(
   }
   if (not susDataProcessed->susVecTot.isValid()) {
     estimateFusedRotationRateEclipse(gyrDataProcessed, fusedRotRateData);
+    // store for calculation of angular acceleration
+    if (gyrDataProcessed->gyrVecTot.isValid()) {
+      std::memcpy(rotRateOldB, gyrDataProcessed->gyrVecTot.value, 3 * sizeof(double));
+    }
     return;
   }
 
@@ -42,6 +46,10 @@ void FusedRotationEstimation::estimateFusedRotationRateSafe(
                                         fusedRotRateParallel, 3);
   } else {
     estimateFusedRotationRateEclipse(gyrDataProcessed, fusedRotRateData);
+    // store for calculation of angular acceleration
+    if (gyrDataProcessed->gyrVecTot.isValid()) {
+      std::memcpy(rotRateOldB, gyrDataProcessed->gyrVecTot.value, 3 * sizeof(double));
+    }
     return;
   }