The effect of multi-periapse burns on planetary escape and capture

The use of multiple periapse burns to transfer between a planetocentric parking orbit and a hyperbolic trajectory with a high thrust propulsion system having constant, finite thrust is investigated. Such multiple burns offer propellant savings as a consequence of reduced velocity losses which accrue over the finite burn time of thrusting maneuvers. Velocity losses for an earth escape phase are calculated for an optimum steering program over a range of parameters that are typical of a Mars mission. These numerically integrated results are compared to velocity losses evaluated with a leading analytic approximation to establish boundaries within which the accuracy of the analytic approximation is adequate for preliminary mission planning purposes. Finally, results of the investigation are used to define typical benefits of the multi-periapse burn concept for Mars exploration missions.