Three-Axis Attitude Maneuver of Spacecraft by Reaction Wheels with Rotation Speed Constraints

Conventionally, spacecraft control their total angular momentum with magnetic torquers or thrusters. However, for a micro interplanetary spacecraft such as PROCYON (Funase et al. 2014), magnetic torquers cannot be used when it is far from the earth and thrusters also cannot be used frequently because of limited fuel storage. In that case, the attitude should be controlled using reaction wheels and the total angular momentum is fixed in the inertial frame. The problem is that when the total angular momentum is large, the wheels are required to store large angular momenta, which, in some attitude conditions, exceed the capacity of the reaction wheels. In order to perform three-axis attitude maneuver using sun sensors and gyroscopes as sensors and reaction wheels as actuators even with a large total angular momentum, the proposed control method applies pointing control of the angular momentum and that of the sun direction in sequence. The results show that the success rate of a three-axis maneuver from a certain attitude to another within one hour using the proposed method is 99.9% on average, even when the spacecraft has a large total angular momentum, while that of the conventional method is 48.3% on average.