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

Development of a reflectivity 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 for earlier warning times of destructive space weather events. A reflectivity control device (RCD) utilizes polymer dispersed liquid crystal (PDLC) material encapsulated between thin 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 with the ability to produce forces on the sail in the sail out-of-plane and in-plane directions. This ability to produce in-plane and out-of-plane force means that the device can be used to support full six-degree-of-freedom (6DOF) 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 currently used for 6DOF sailcraft control. The resulting lighter weight of the sailcraft will allow for improved warning time for adverse space weather events.