A Methane Arcjet Development

A methane (CH4) electrothermal arcjet holds the potential of increased performance and longer lifetime than traditional ammonia or hydrazine arcjets. The potential drawback of CH4 arcjet is formation of soot that could cause spacecraft contamination and decreased performance. In the Phase I program we will determine the extent of soot formation and explore ways to reduce it. This will be done by testing four nozzle/anode geometries in a 2kW methane arcjet. The plasma expansion rate and nozzle temperature distribution are the major test parmeters. Following the parametric tests, an eight hour duration test will be conducted with a selected anode geometry at a selected operating condition. Additionally, we will construct and test a new cathode that has the potential for unlimited lifetime and reduced cathode voltage drops, which is based on previous work with CH4 plasmas. The experimental program will be supported by concurrent numerical analysis of soot formation. This work will be performed by a subcontractor - Aerodyne Research, Inc.