Significant efforts are being made to improve the safety of the solid rocket motor (SRM) for the shuttle. The SRM is a laminated structure consisting of four layers of materials: a steel casing, bonded to NBR insulation, the liner, and the propellant. One of the candidate inspection techniques is a thermal technique which analyzes the response of the SRM to an external heat source for detection of disbonds at the interfaces between the steel, NBR and fuel. Computational simulations of experimental measurements can provide limits of the effectiveness of the technique and easily assume a variety of different defect geometries to determine their detectability without the expense of making many different samples. Simulations can also provide useful information for the experimenter including the heating protocol that will provide the greatest contrast and the typical flaw size that can be detected.