Summary

Description

Radioisotope Electric Propulsion (REP) offers the prospect for a variety of new science missions by enabling use of Hall Effect propulsion in the outer solar system, particularly at distances beyond the limits of practical solar photovoltaic power. Radioisotope Power System (RPS) technology under development by the Science Mission Directorate (SMD) provides high system-specific power and lifetime needed for REP applications. The low power (0.5 to 1.0 kW) and multiyear (30,000 hour) lifetime HET systems needed for these missions will be addressed in the proposed multi-phase effort. The project leverages a long life 600 W Hall thruster currently under development by Busek as part of the 2007 Innovative Partnership Program based of an innovative life-extending technology developed under SMD In-Space Propulsion Technology (ISPT) project by the NASA Glenn Research Center. In Phase I we will evaluate system level needs to meet REP mission requirements. The life time of the existing cathode will be determined by a combination of experimental and numerical methods. A methodology and algorithms for sensing and suppressing thruster discharge current oscillations will be incorporated into the thruster control system. An integrated system demonstration that includes the thruster life extension technology will be performed.