Coplanar circular-to-circular orbit transfer guidance with constant-thrust acceleration

A semi-analytical solution for circular-to-circular planar orbit transfers is presented. In particular, the problem is addressed with a judiciously chosen maneuver sequence consisting of radial thrust, velocity normal thrust, and coast arcs. The radial thrust segments admit fully-analytical solutions, while the velocity normal thrust portion only admits a semi-analytical solution. For a given constant-acceleration thrust value, the range of radii to which the orbit can be changed is presented with two different schemes. Orbit escape is also demonstrated with successive applications of the first scheme. However, all the presented solutions are suboptimal in terms of time and fuel use.