Iowa State University
Dielectric spectrometry will be performed on select spacecraft materials (i.e. heat shield materials, structural materials and insulating foams) to examine their capacitance and permittivity under controlled humidity. Three types of samples will be tested for each selected material, a dry, defect free sample, samples with known defects and moisture levels, and samples of unknown condition as a test of validity. Tests will be conducted from three microhertz to three gigahertz at temperatures ranging from -160°C to 400°C in order to obtain a full dielectric profile. The complex dielectric spectra acquired will be analyzed using computational modeling in order to determine the fit parameters associated with that material. These dielectric spectra and computational models will be used as the basis for proposals for new capacitance three-dimensional permittivity mapping sensor systems for monitoring structural health, extending a material’s lifetime in high humidity environments (like those of Florida) and in forming improved repair processes.