Attitude Control of Solar Sail with Reflectivity Control Devices

Solar sails offer a promising solution for fuel free propulsion, enabling novel mission profiles and deeper space exploration. While reaction wheels are standard for spacecraft attitude control, the large moment of inertia of solar sails often lead to frequent reaction wheel saturation, necessitating momentum offloading via additional control methods. Magnetorquers have historically been used for this purpose. This paper investigates Reflectivity Control Devices (RCDs) as an alternative method for momentum management, aiming to prevent reaction wheel saturation. A dynamic model of a solar sail in a Sun synchronous orbit is developed, incorporating disturbance torques to assess control. Numerical simulations evaluate the effectiveness of RCDs in offloading reaction wheel momentum and preventing saturation. The results indicate additional applications for RCDs in Earth orbit as well as potential for deep space missions where magnetorquers cannot be used.