Method to Have Multilayer Thermal Insulation Provide Damage Detection

Spacecraft multilayer thermal insulation here to date has been used to reduce thermal radiation heat losses. Each layer is a thin layer of material, such as Mylar, coated with a reflective and electrically conductive material like aluminum. A method to create a wireless damage-detection array using the insulation has been developed. One layer of the insulation is designed as an array of passive open-circuit electrically conductive and reflective spiral patterns that are capable of storing electrical and magnetic energy when powered via an external oscillating magnetic field supplied by an antenna. Once electrically active, each pattern produces a harmonic magnetic field. No electrical connections are used between the patterns, on the patterns or to the patterns thereby allowing each pattern to be independent and also eliminating one cause of failure to circuits. The responding field frequency changes if any pattern is damaged. The spiral-pattern design provides sufficient area coverage for thermal insulation. Other insulation layers are designed to allow the responding magnetic fields to permeate the insulation layers. Arrays have been tested using hypervelocity impact projectiles of 1-3.6 mm diameter with speeds ranging from 6.7-7.1km/s6.7-7.1km/s. [PUBLISHER ABSTRACT]