POWER LIMITED SOFT LANDING ON AN ASTEROID

This work is concerned with the final approach phase and vertical land ing on a spherical asteroid with a power limited, electrically propell ed spacecraft. With gravitational effects taken into account, a new so lution to the fuel optimal vertical landing on an asteroid was obtaine d. In this particular solution the spacecraft commanded acceleration i s colinear with the vehicle velocity, and the spacecraft trajectories are restricted to a plane. Based on qualitative methods of analysis, t he guidance strategy and the resulting trajectories were studied. It i s shown that these fuel optimal trajectories effectively assure a vert ical soft landing on the asteroid. Results of numerical simulations fo r the vertical landing starting from an elliptic orbit are presented.