Charge-exchange plasma contamination on SMART-1: First measurements and model verification

SMART-1, launched in fall 2003, is Europe's first moon satellite. It shall demonstrate Solar-Electric Propulsion using a PPS-1350 hall thruster. One of the main mission investigations is the characterization of the thruster's charge-exchange ion environment. Two instruments support this analysis: EPDP, consisting of a Langmuir probe, RPA analyser and a solar cell sample, and SPEDE, consisting of two current collection spheres supported by two short booms. ARC Seibersdorf research developed a Particle-In-Cell plasma simulation to support and predict the thruster's induced plasma environment around SMART-1. This paper will give an overview of the modeling approach and a comparison of the model will test results gained during the STENTOR ground test campaign using a similar thruster. We will also report a first interpretation of the measurements from EPDP and SPEDE on SMART-1 and will compare them with the actual model predictions. This analysis shall be used to actually validate the simulation tool to reliably predict charge-exchange plasma environments on future missions using electric propulsion.