Simulation Evaluation of Re-entry Control Technique for Small Satellite ELS-R100

Abstract

This paper proposes a deorbit control strategy for a small satellite with a high-thrust propulsion. Tohoku University and ElevationSpace Inc. have been developing a 200 kg class satellite, ELS-R100. The objectives are to demonstrate the deorbit control using a 100 N-class propulsion and the 30 kg re-entry capsule recovery in the target area. During deorbit, the satellite's attitude control using Reaction Control System (RCS) thrusters is essential. Managing RCS thrust and direction in the threeaxis control, and the nutation angle during spinning are crucial for establishing attitude control. This research evaluated control performance during the deorbit maneuver due to the re-entry simulation by MATLAB/Simulink. The results show that the three-axis method is advantageous regarding the index of attitude stabilization, and the spin method has inferior control for thruster injection. However, in the three-axis case, the consumption of the RCS propellant tends to increase in response to change in the center of mass and the thrust vector errors, making it challenging to ensure the system feasibility required for small satellites. In the spin case, the proposed method covers the target landing area of the capsule even with unexpected maneuver errors, and we concluded that the spin control is a more robust maneuver approach and becomes a major method for re-entry missions of small satellites.