Trajectory design with hybrid low-thrust propulsion system

A novel mission concept based on a hybrid low-thrust propulsion system is proposed and discussed. A solar electric propulsion thruster is coupled with an auxiliary system providing an inverse square radial thrust. In this way the spacecraft is virtually subjected to a reduced gravitational solar force. The primary purpose of this paper is to quantify the impact of the reduced solar force on the propellant consumption for an interplanetary mission. To this end the steering law that minimizes the propellant consumption for a circle-to-cirele rendezvous problem is found using an indirect approach. The hybrid system is compared with a conventional solar electric thruster in terms of payload mass fraction deliverable for a given mission. A tradeoff between payload size and trip time is established.