DETERMINATION OF FUNDAMENTAL LOW-THRUST CONTROL FREQUENCIES FOR FITTING SEQUENCES OF ORBITAL STATES

Determination of an effective low-thrust control law that connects a series of orbital states is studied using an averaged method based on Fourier series representation of the thrust control. Time-variation of the control law is introduced through segmentation of an orbital targeting problem into multiple two-point boundary value problems and optimization of the control law for each segment. Least-squares analysis is also used to efficiently calculate the low-thrust transfer that minimizes a general thrust-based cost function through a set of states. Applications of these methods to low-thrust mission design and space situational awareness are discussed.