TABLE OF CONTENTS The theory of optimal low-thrust orbit transfer has received a great deal of attention in the astrodynamics and flight mechanics literature over the past several decades. This chapter begins with a detailed description of some fundamental analytic results obtained by Edelbaum, which are widely in use by the practitioners in the aerospace industry. The reader, after becoming familiar with the simplified transfer analysis, is invited to consider the treatment of the exact transfer problem in the subsequent sections. Drawing on the pioneering work of the Americans Broucke, Cefola, and Edelbaum, who perfected the theory of orbital mechanics in terms of nonsingular orbital elements, examples of optimal orbit transfers are generated and discussed, and all the relevant equations needed to develop unconstrained orbit transfer computer codes are exposed and derived.
