CHARACTERIZATION OF CANDIDATE SOLAR SAIL MATERIALS SUBJECTED TO ELECTRON RADIATION

Solar sailing is a unique form of propulsion in which a spacecraft gains momentum from incident photons. Solar sails are not limited by reaction mass and provide continual acceleration, reduced only by the lifetime of the light-weight film in the space environment and the distance to the Sun. Once considered difficult or impossible, solar sailing has left the realm of science fiction for the realm of possibility. Any spacecraft using this method would need to deploy a thin sail that could be as large as many kilometers in extent. The availability of strong, ultra lightweight, and radiation-resistant materials will determine the future of solar sailing. The National Aeronautics and Space Administration’s (NASA’s) Marshall Space Flight Center (MSFC) is concentrating research into the use of ultra light-weight materials for spacecraft propulsion. MSFC’s Space Environmental Effects Team is actively characterizing candidate solar sail materials to evaluate thermo-optical and mechanical properties after exposure to space environmental effects. This paper describes irradiation of candidate materials with energetic electrons in vacuum to determine the hardness of several candidate sail materials. [Hardness is defined as the amount of electron fluence (electrons/area) required to cause the sail material to fail.] This paper describes the testing procedure and preliminary results of this investigation. Comparisons to approximate the engineering functional lifetimes of candidate sail materials will be shown.