Carbon nanotube (CNT) materials are exciting candidates for spacecraft by virtue of their unprecedented specific mechanical and electrical properties. Analysis in this thesis identifies 14 types of CNT-sheets with distinct variables, and discovers the mechanisms controlling macroscopic properties. Specimen variables include acid treatment, polymer coatings, production method, and combinations. Mechanical testing includes tensile-tests and investigation with scanning electron microscopy and energy-dispersive x-ray spectroscopy. Physical properties testing include electromagnetic interference (EMI) shielding effectiveness (SE) and electrical conductivity. This research also highlights the resilience of CNT-sheets to atomic oxygen and thermal fatigue qualifying them for performance in space. EP CNT-sheets have decreased mechanical and electrical properties from a large composition of impurities. Acid treatment increases both mechanical and electrical properties. The acid treated sheets are better consolidated and have reduced impurities which lead to superior properties. This investigation found that strength and EMI SE are unaffected by atomic oxygen and thermal fatigue. Young’s modulus increases in both environments while strain decreases. Electrical conductivity decreases from atomic oxygen for both specimens as a result of reduced conductive area. Thermal fatigue only diminishes electrical conductivity in the more compact acid treated sheets
