Attitude Estimation for A Deorbiter CubeSat

This paper investigates the attitude estimation capabilities of a debris-removing nanosatellite called deorbite CubeSat. The spacecraft is designed based on the utilization of commercially-available components with long space heritage which are embedded in an eight-unit form factor. The attitude estimation machinery employed in this work is a discrete time, quaternion-based, extended Kalman filter, which utilize measurements provided by a three-axis rate sensor, five sin sensors, and a three-axis magnetometer. To obtain a linear state space model, gravity gradient and magnetic disturbance torque are included in the plant model, and the model is linearized with respect to the process noise and the states, namely the inertial angular velocities and the quaternions. measurement. noises are modelled based on zero-mean Gaussian distributions and are quantified based on the performance of the state-of-the art, commercial-of-the-shelf devices. A Monte Carlo simulation is created to analyze the performance of the estimator again various initial angular velocities and quaternions, both in the sunlit and in the eclipsed portions of the orbit. In light of the results, the accuracy of the deorbiter CubeSat's attitude knowledge is discussed.