Influence of thrust modulation on a satellite with flexible non-latching booms

The use of CubeSats is increasing to a wide range of areas in science and technology with some of them requiring an accurate Attitude Determination and Control System (ADCS) and deployable structures such as booms. However, small satellites commonly do not have latching systems to lock their booms, which introduce vibrations and oscillations and might degrade the ADCS performance. Also, some applications propose missions with CubeSats operating in close proximity and coordination, requiring thrusters to perform orbit maneuvers such as the planned ITASAT-2 spacecraft formation flying mission, which will have non-latching booms and a thruster. These thrusters can excite the satellite’s non-latching flexible booms, intensifying their impact on the ADCS. Additionally, on-off thrusters are usually controlled using a Pulse-Width Modulation (PWM), introducing more effects in the system’s dynamic. Hence, motivated by the ITASAT-2 mission, this work aims to understand the impact of a thruster’s PWM parameters in the non-latching flexible booms dynamics. Also, this work presents a framework to obtain the influence of PWM parameters on a satellite, which can be applied to other small spacecraft. The results show that booms’ deformation decreases when the thruster provides a continuous force, compared to a modulated force. Peaks in deformation and rotation were identified near frequencies of the non-latching flexible booms’ system. Further, it was verified that resonances might occur in latched booms at distinct PWM periods. Moreover, the influence of the non-latching mechanism and PWM parameters was observed in the system forming regions of larger deformation.