From 4193a565a42971d9680dc35083bbed3d326357bc Mon Sep 17 00:00:00 2001
From: meggert <eggertm@irs.uni-stuttgart.de>
Date: Fri, 22 Mar 2024 11:39:18 +0100
Subject: [PATCH 1/2] i hate this

---
 mission/controller/acs/Guidance.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mission/controller/acs/Guidance.cpp b/mission/controller/acs/Guidance.cpp
index 2c1b3c63..07730e09 100644
--- a/mission/controller/acs/Guidance.cpp
+++ b/mission/controller/acs/Guidance.cpp
@@ -303,9 +303,9 @@ void Guidance::comparePtg(double currentQuat[4], double currentSatRotRate[3], do
   // First calculate error quaternion between current and target orientation without reference
   // quaternion
   double errorQuatWoRef[4] = {0, 0, 0, 0};
-  QuaternionOperations::multiply(currentQuat, targetQuat, errorQuatWoRef);
+  QuaternionOperations::multiply(targetQuat, currentQuat, errorQuatWoRef);
   // Then add rotation from reference quaternion
-  QuaternionOperations::multiply(refQuat, errorQuatWoRef, errorQuat);
+  QuaternionOperations::multiply(errorQuatWoRef, refQuat, errorQuat);
   // Keep scalar part of quaternion positive
   if (errorQuat[3] < 0) {
     VectorOperations<double>::mulScalar(errorQuat, -1, errorQuat, 4);
-- 
2.34.1


From 9f033411089ba7c7cf537fa2fb69bb8a05c4313e Mon Sep 17 00:00:00 2001
From: meggert <eggertm@irs.uni-stuttgart.de>
Date: Fri, 22 Mar 2024 11:40:00 +0100
Subject: [PATCH 2/2] changelog

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 649cf44f..6510f227 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,10 @@ will consitute of a breaking change warranting a new major release:
 
 # [unreleased]
 
+## Fixed
+
+- Fixed wrong order in quaternion multiplication for computation of the error quaternion.
+
 # [v7.7.4] 2024-03-21
 
 ## Changed
-- 
2.34.1