Status of Solar Sail Material Characterization at NASA'S Marshall Space Flight Center

Near term solar sail propelled science missions are targeting the Lagrange point 1 (Ll) as well as locations sunward of L1 as destinations. These near term missions include the Solar Polar Imager' and the L1 Diamond '. The Environmental Effects Group at NASA's Marshall Space Flight Center (MSFC) continues to actively characterize solar sail material in preparation for these near term solar sail missions. Previous investigations indicated that space environmental effects on sail material thermo-optical properties were minimal and would not significantly affect the propulsion efficiency of the sail. These investigations also indicated that the sail material mechanical stability degrades with increasing radiation exposure. This paper will further quantify the effect of space environmental exposure on the mechanical properties of candidate sail materials. Candidate sail materials for these missions include Aluminum coated Mylar(TradeMark), Teonex(TraeMark), and CP1 (Colorless Polyimide). Experimental data will be presented on sail material response to charged particle radiation and subsequent Hypervelocity Impact (HVI). Data will also be presented indicating mechanical property variations in sail material resulting from electron exposure, proton exposure, and a combined electron and proton exposure. Tabular data consisting of areal density, thickness, thermo-optical, mechanical, and electrical properties, vacuum stability and outgassing will be presented.