diff --git a/AstroLib/Src/AsAttitudeParam_2023.cpp b/AstroLib/Src/AsAttitudeParam_2023.cpp
index ac0c2cfdc360ebb26320d5cef50e36195b6bd664..cde58dbbbc41a02c4ca39882049ff9139585d0a2 100644
--- a/AstroLib/Src/AsAttitudeParam_2023.cpp
+++ b/AstroLib/Src/AsAttitudeParam_2023.cpp
@@ -1,4 +1,4 @@
-
+
 #include "AsAttitudeParam_2023.h"
 #include "AsCoordinate.h"
 #include "AsMath.h"
@@ -759,4 +759,37 @@ void AsMtxToEuler212(const CMatrix<double>& mtx, CEuler& euler)
 		euler.m_Angle1 = AsCPI-atan2(mtx[1][0], -mtx[1][2]);
 		euler.m_Angle3 = AsCPI-atan2(mtx[0][1], mtx[2][1]);
 	}
+}
+
+
+void AsMtxToEuler121(const CMatrix<double> &mtx,
+					 CEuler &euler)
+	CEuler &euler)
+{
+	// euler.m_Angle1 = atan2(mtx[0][1], -mtx[0][2]);
+	// euler.m_Angle2 = acos(mtx[0][0]);
+	// euler.m_Angle3 = atan2(mtx[1][0], mtx[2][0]);
+
+	if (fabs(mtx[0][0]) != 1)
+	{
+		euler.m_Angle1 = atan2(mtx[0][1], -mtx[0][2]);
+    }
+
+	else
+	{
+		euler.m_Angle1 = 0;
+		double summ = atan2(mtx[1][1], mtx[1][2]);
+		if (mtx[2][0] == -1)
+		double summ = atan2(-mtx[2][1], mtx[1][1]);
+		if (mtx[0][0] == -1)
+		{
+			euler.m_Angle2 = AsCPI;
+			euler.m_Angle3 = summ;
+		}
+		else
+		{
+			euler.m_Angle2 = 0;
+			euler.m_Angle3 = summ;
+		}
+	}
 }
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