NON-DESTRUCTIVE INSPECTION TECHNIQUES FOR MULTI-LAYER AND FOAM INSULATIONS

TO CERTIFY INSTALLED MULTI-LAYER OR FOAM INSULATION FOR FUTURE USE, A NONDESTRUCTIVE INSPECTION TECHNIQUE IS NEEDED WHICH IS CAPABLE OF DETECTING AND MEASURING PHYSICAL CONDITIONS OR ABNORMALITIES WHICH ARE WITHIN THE INSULATION AND CANNOT BE OBTAINED BY VISUAL INSPECTION. PHYSICAL CONDITIONS OF CONCERN INCLUDE THE INSULATION THICKNESS, GAPSBETWEEN INSULATION PANELS OR WITHIN A FOAM, AND CORROSION OFREFLECTIVE COMPONENTS. THIS PROJECT EVALUATES THE FEASIBILITY OF USING ELECTROMAGNETIC AND ELECTROSTATIC METHODS FOR DETECTING AND MEASURING THESE CONDITIONS. IN THE ELECTROSTATIC TECHNIQUE, CAPACITOR PLATES ARE A UNIQUE AND INTEGRAL PART OF THE INSULATION. THE OBJECTIVE OF PHASEI OF THIS EFFORT IS TO VERIFY THAT THE PROPOSED TECHNIQUES CAN BE USED AND THAT THE MEASUREMENTS OBTAINED ARE ADEQUATE TO ALLOW A RELIABLE CERTIFICATION OF THE INSULATION. THE EFFORT TO MEET THIS OBJECTIVE CONSISTS OF NUMEROUS TESTS OF EACH TECHNIQUE ON SAMPLES OF INSULATION WHICH CONTAIN THE PHYSICAL CONDITIONS OF INTEREST. THE INSPECTION TECHNIQUE BEING DEVELOPED IS A PARTICULARLY VALUABLE TOOL FOR RECERTIFYING INSULATION IN A REUSABLE SPACE VEHICLE.