Abstract: The chaotic dynamics in an attitude maneuver of a coupled slosh\|flexible spacecraft from minor axis to major axis under the influence of dissipative effects due to fuel sloshing and a small flexible appendage constrained to undergo only torsional vibration is investigated. The slosh\|coupled
flexible spacecraft carrying a sloshing liquid is considered in attitude maneuver as multi\|body system with the sloshing motion modeled as a spherical pendulum. The focus in this paper is on the way in which the dynamics of the liquid sloshing and flexible appendage vibration are coupled. The equations of motion are derived. Melnikov’s integral is used to predict the transversal intersections of the stable and unstable manifolds for the perturbed system. An analytical criterion for chaotic motion is derived in terms of the system parameters. This criterion is evaluated for its significance to the design of spacecraft. The dependence of the onset of chaos on quantities such as body shape, damping ratio, liguid filled ratio and torsional vibration frequency of flexible appendage are investigated. In addition, it is shown that after passive reorientation maneuver, a spacecraft carrying a sloshing liquid will end up with periodic limit loop motion other than a final major axis spin because of the intrinsic non\|linearity of fuel slosh. Furthermore, an extensive numerical simulation is carried out to validate the Melnikov’s analytical result.

Key words: Attitude maneuver, Liquid-filled spacecraft, Flexible appendage, Liquid sloshing