Date of Award


Access Type

Thesis - Open Access

Degree Name

Master of Science in Mechanical Engineering


Mechanical Engineering

Committee Chair

Patrick Currier, Ph.D.

First Committee Member

Sergey Drakunov, Ph.D.

Second Committee Member

Charles Reinholtz, Ph.D.


Solar Sail spacecraft have become increasingly popular due to their ability to perform long term missions without the need for propellant. Because solar sail propulsion is so unique, most research has been focused on developing new mechanical control techniques. However, it can be argued that more advanced control algorithms can be used to mitigate the shortcomings of commonly used control actuators, specifically reaction wheels, when applied to solar sails. This thesis will research how a sliding mode controller compares to a PID controller with respect to settling time and state response error over a range of maximum reaction wheel torque values. The actuator saturation and actuator energy are then compared for two different sliding mode controllers and a PID controller. It was found that the sliding mode controller performed at minimum 14% better in terms of settling time and 7.7% better in terms of state response error, however the PID controller performed 24% better in terms of actuator saturation and energy. Further research should be done to study the potential benefits of sliding mode controllers in terms of their benefits to reduce actuator saturation and energy.