A MATLAB Script for Designing Low-thrust Spiral Trajectories with Constant Periapsis Radius

This document describes a MATLAB script named demo_lts that can be used to design and analyze a low-thrust spiral trajectory with a constant periapsis radius. The user provides the classical orbital elements of the initial Earth park orbit along with the final or “target” orbital eccentricity. The spacecraft orbital motion is modeled using modified equinoctial orbital elements.