Adjoint—control transformations for solving practical optimal control problems

This paper is concerned with some reformulations of the classical computational scheme for solving optimal control problems via Pontryagin's maximum principle. The purpose is to alleviate some well known difficulties involved in solving a two-point boundary value problem in terms of adjoint variables. To this end there is discussion of the avoidance of explicit use of transversality conditions and the use of initial control rather than adjoint variables as the basis of the iterative procedure. The application of these ideas to some practical problems of spacecraft trajectory optimization is considered.