A Construction Methodology of the Large Space Structures under Gravity Gradient Stabilization

Abstract

A construction methodology of the large space structures is investigated assuming SPS (Solar Power Satellite) 2000 model. The structural elements are launched 10 times and assembled on an orbit to a final configuration using the simple, unmanned robot. At first, the basic construction scenario is studied using the gravity gradient (G. G.) stability map from the single rigid body equations. Then, the equations of motion of multi-chain bodies with flexible joints was developed and the dynamic behavior is investigated. The attitude rate change caused by MOI (Moment of Inertia) charge is found significant source of the attitude drift, as compared with the robot and flexible joints motion. Finally, the effects of disturbing torques are studied. The solar radiation can be a significant disturbance source. However, by reducing the CP-CG distance through modifying the cross section shape and by applying the geomagnetic torque, where necessary, it can be controlled within allowable limit.