Dynamics of Spacecraft Orbital Refueling
A quantitative collation of relevant parameters for successfully completed experimental on-orbit fluid transfers and anticipated orbital refueling future missions is performed. The dynamics of connected satellites sustaining fuel transfer are derived by treating the connected spacecraft as a rigid body and including an internal mass flow rate. An orbital refueling results in a time-varying local center of mass related to the connected spacecraft. This is accounted for by incorporating a constant mass flow rate in the inertia tensor. Simulations of the equations of motion are performed using the values of the parameters of authentic missions in an endeavor to provide conclusions regarding the effect of an internal mass transfer on the attitude of refueling spacecraft. The effect of a nonzero internal mass flow rate is qualitatively investigated and a parametric analysis is performed in order to validate the conclusion. A damping effect occurs as a result of the internal mass transfer; implying that the control effort required to stabilize spacecraft sustaining fuel transfer could be less than what is necessary in the absence of an internal mass flow rate.