Orbital motion approximation with constant circumferential acceleration

The aim of this paper is to analyze the two-dimensional trajectory of a spacecraft with a constant, low, and circumferential propulsive acceleration, using the procedure proposed by Bombardelli et al. The latter describes the spacecraft dynamics through a set of generalized (nonsingular) orbital parameters, and uses a perturbative approach to get an analytical representation of the resulting orbit in case of tangential propulsive acceleration, that is, when the thrust and velocity vectors are parallel. This method gives accurate results when the propulsive acceleration magnitude is significantly smaller than the local gravitational pull, and its effectiveness in trajectory approximation has been discussed in the noteworthy cases of a spacecraft propelled by either a solar sail, or an electric solar wind sail with fixed attitude.