Electric Thrust Device Requirements for Interplanetary Spacecraft

This paper discusses the requirements that must be met by electric thrust devices in order to be used with interplanetary spacecraft. Two missions, a Mars orbiter and a Jupiter capture, chosen as representative of the time periods following 1965 and 1970, respectively, are analyzed to determine the thrust and specific impulse requirements of an electric propulsion system. The state of the art of electric thrust devices is discussed, and it is concluded that, with expected advances, ion motors can meet all of the requirements of interplanetary missions, with magnetohydrodynamic motors a promising backup.