Attitude dynamics of the Genesis spacecraft

The Genesis spacecraft has a science payload that requires a spinning platform but that also requires mechanical reconfigurations of a type that are normally not found on a spin-stabilized vehicle. This paper addresses the dynamics of these reconfigurations and describes the resulting constraints on vehicle operations. The reconfigurations in question include the opening and closing of the reentry capsule's massive cover, which must be done in a way that avoids tumbling the vehicle. Other critical reconfigurations involve exposing different sets of solar wind collectors without violating tight attitude constraints. The various mechanical reconfigurations, attitude maneuvers, and orbital maneuvers all induce nutational motions that must be attenuated in a timely manner. Hence, nutation damping requirements are also addressed. Key damper design trades are discussed and the reasons for selecting the final configuration are outlined. Finally, the design and test of the vehicle's passive nutation dampers are described.