Thrust Evaluation of an Arcjet Thruster Using Dimethyl Ether as a Propellant

Abstract

This paper describes the performance of an arcjet thruster using dimethyl ether (DME) as a propellant. DME, an ether compound, has adequate characteristics for space propulsion systems; DME is storable in a liquid state without a high pressure or cryogenic device and requires no sophisticated temperature management. DME is gasified and liquefied simply by adjusting temperature, whereas hydrazine, a conventional propellant, requires an iridium-based particulate catalyst for its gasification. In this study, thrust of the designed kW-class DME arcjet thruster is measured with a torsional thrust stand. Thrust measurements show that thrust is increased with propellant mass flow rate, and that thrust using DME propellant is higher than when using nitrogen. The prototype DME arcjet thruster yields a specific impulse of 330 s, a thruster efficiency of 0.14, and a thrust of 0.19 N at 60-mg/s DME mass flow rate at 25-A discharge current. The corresponding discharge power and specific power are 2.3 kW and 39 MJ/kg.

Performance Characteristics of a DME Propellant Arcjet Thruster

“…In a past study, a thruster using a flat 2-type cathode was tested to evaluate performance 9,10) . Flat4-type cathode was also used to investigate dependence on cathode diameter.…”

“…The DME arcjet thruster also exhibits both high-and low-voltage modes. Thrust was measured with a vertical thrust stand using a torsional spring to evaluate discharge power, thrust, specific impulse, and thruster efficiency 9,10) . In this study, a prototype 1-kW class DME arcjet thruster was tested to clarify the correlation between performance and cathode configuration at a discharge current of 13 A.…”