An optimal thruster configuration design and evaluation for quick step

Abstract

A procedure to calculate the margin of safety of a thruster system is presented. The margin of safety is the excess control authority of a thruster system available to overcome the worst case disturbances and is based on calculating the minimum control authority of the thruster system normalized by the worst case disturbances. Various controllers are presented for both one-sided and two-sided thrusters and their minimum control authorities are compared. Finally, a procedure to optimize a thruster system configuration in the sense of maximizing the margin of safety is presented and applied to the design of a thruster system for the Quick STEP spacecraft, an orbiting gravitational physics experiment. The techniques presented in this article are generally applicable to many other multi-degree of freedom actuation systems like the primary flight control effectors on a highly maneuverable aircraft for example.