Simulation of Single Gimbal Control Moment Gyroscopes (SGCMG) Cluster for Microsatellite Maritime Surveillance Mission

The potential for agile missions for small satellites exists through development of single gimbal control moment gyroscopes (SGCMG). An SGCMG cluster comes with additional complexity and volume requirements, but efforts in their development have reduced their overall size while providing higher torque over similarly sized reaction wheels. In this paper, we present a feasibility study of a small satellite using a small volume pyramid SGCMG cluster for coastline monitoring through Simulink. Two realistic torque profiles for sweeping capture of complex coastlines within one minute were generated using STK, requiring maximum torques of 0.190 and 0.218 Nm and rapid slew rate. The torques are beyond the capabilities of a similarly sized reaction wheel, which can only output maximum torques of 0.020 Nm. The torque profiles were replicated using simulated SGCMG cluster using modelled SGCMG scaled for small satellites. Results show that the SGCMG pyramid cluster meets the required torque profiles with less than 0.3 degrees of pointing error throughout the maneuver. A novel SGCMG hardware is currently under development and preliminary analysis indicates sufficient torque for agile missions such as coastal monitoring presented in this paper. The viability of SGCMG cluster provide promising alternative for ACS design of small satellites where agility have been limited by existing attitude actuators