Space Acoustics performed the SXI instrument thermos-elastic analysis, to predict deformation of the instrument during normal thermal variations in orbit. Temperature maps are calculated in ESATAN for specific analysis cases and orbital positions, and superimposed onto detailed FEM models to calculate displacements.  Instrument FEM models were developed from standard models to provide accurate spatial correlation to thermal maps and generate thermal distortions and postprocessing to validate instrument alignment and focus performance.  Thermal model/FEM model mapping was performed in ANSYS workbench using advanced algorithms, verified by test cases.