Active Material Technology to Improve Solar Sail Performance for Space Weather Monitoring

Development of a reflection control and direction device (RCDD) is proposed. This innovative device will progress the state of the art for propulsion of solar sails used to fly space weather monitoring sensors to sub-LaGrange point orbits for earlier warning times of impending destructive space weather events. A reflection control device (RCD) utilizes polymer dispersed liquid crystal (PDLC) material encapsulated between thin membrane layers of clear polyimide film to create a material that can switch between opaque and transparent by applying an electrical voltage across the material. This RCD will be integrated with a flexible membrane diffraction grating that will change the direction of the incident light transmitted through the RCD. With this innovation, the device becomes an RCDD. The RCDD will have the ability to produce forces on the sail in both the sail out-of-plane and in-plane directions. This ability to produce inplane force as well as out-of-plane force means that the device can be used to control both orientation and roll of the solar sail. The RCDD will be able to support full six-degree-of-freedom control of the spacecraft compared to the RCD which has no roll control authority. This innovation will eliminate the need for heavy and complex opto-mechanical devices such as motorized tip vanes, sail warping mechanisms or other current solutions available for 6DOF sailcraft control. The resulting lighter weight of the sailcraft will increase the system’s characteristic acceleration providing lower sub-LaGrange point orbits and improving warning time for adverse space weather events.