Trajectory analysis and performance for SEP Comet Encke missions

A summary of the performance of Solar Electric Propulsion spacecraft for Comet Encke missions for the 1980, 1984 and 1987 mission opportunities is presented together with a description of the spacecraft trajectory for each opportunity. Included is data for rendezvous trajectories for all three opportunities and data for a slow flyby mission during the 1980 opportunity. A range of propulsion system input powers of 10 to 20 kW are considered together with a constant spacecraft power requirement of 400 watts. The performance presented in this paper is indicative of that using 30 cm Mercury electron bombardment thrusters that are currently being developed. Performance is given in terms of final spacecraft mass and is thus independent of any particular spacecraft design concept.