Slew Maneuver Constraints for Agile Flexible Spacecraft
Traditional spacecraft design paradigms rely on stiff bus structures with comparatively flexible appendages. More recent trends, however, trade deployed stiffness for packaging efficiency to stow apertures with larger areas inside existing launch vehicles. By leveraging recent advances in materials and structures, these spacecraft may be up to several orders of magnitude lighter and more flexible than the current state-of-the-art. Motivated by the goal of achieving agility despite structural flexibility, this paper proposes a quantitative method for determining structure-based performance limits for maneuvering flexible spacecraft. It then uses a geometrically nonlinear flexible multibody dynamics model of a representative very flexible spacecraft to verify this method. The results demonstrate that, contrary to common assumptions, other constraints impose more restrictive limits on maneuverability than the dynamics of the structure. In particular, it is shown that the available attitude control system momentum and torque are often significantly more limiting than the compliance of the structure. Consequently, these results suggest that there is an opportunity to design less-conservative, higher-performance space systems that can either be maneuvered faster, assuming suitable actuators are available, or built using lighter-weight, less-stiff architectures that move the structure-based performance limits closer to those of the rest of the system.
© 2023 by Michael A. Marshall and Sergio Pellegrino. The authors thank Antonio Pedivellano for help in developing the high-fidelity Abaqus finite element model used in the homogenization procedure mentioned in Sec. V. The authors likewise thank Dan Scharf, W. Keats Wilkie, and Jay Warren for the helpful comments and insightful discussions regarding this work. This work benefited from ideas and discussions with Mike Paul Hughes and the other participants at the "Non-Nuclear Exploration of the Solar System" workshop organized by the W. M. Keck Institute for Space Studies in April 2021. M. A. Marshall was supported by a NASA Space Technology Research Fellowship. Financial support from the California Institute of Technology (Caltech) Space Solar Power Project is also gratefully acknowledged.
Accepted Version - 2023_Slew_maneuver_constraints_SciTech.pdf