Date of Award

Summer 2006

Document Type

Thesis - Open Access

Degree Name

Master of Science in Aerospace Engineering


Aerospace Engineering

Committee Chair

Dr. Sathya Gangadharan

Committee Member

Dr. Yi Zhao

Committee Member

James Sudermann


The nutation (wobble) of a spinning spacecraft in the presence of energy dissipation is a well-known problem in dynamics and is of particular concern for space missions. Its rate of growth is characterized by the Nutation Time Constant (NTC). For analytical prediction of the NTC, fuel slosh is often modeled using simple mechanical analogs such as pendulums or rigid rotors coupled to the spacecraft. Identifying model parameter values which adequately represent the sloshing dynamics is the most important step in obtaining a good NTC estimate. Currently, the identification of the model parameters is a laborious trial-and-error process in which the equations of motion for the mechanical analog are hand-derived, evaluated, and their results compared with the experimental results. This research is a pioneering effort toward automating the parameter identification process by using a MATLAB/SimMechanics based computer simulation modeling of a free-surface fuel slosh in a spherical propellant tank of a spacecraft.