Progress on the MET ( microwave electrothermal) thruster with water propellant

Summary form only given. Progress on the MET thruster using water vapor propellant is reported. The MET heats gas in a vortex stabilized, electrodeless, microwave discharge for propulsion. In this research the start-up and asymptotic behavior of the MET specific impulse with increasing run time is investigated. It is found that after a run time of approximately thirty seconds, that the MET thruster running on water vapor achieved a specific impulse of approximately 900 seconds, in agreement with previous research. Chemical physics code runs with, have confirmed the high specific impulse numbers for water as being due to rapid hydrogen-oxygen recombination in the nozzle during expansion and the high source temperature in the electrodeless microwave discharge of approximately 8000 K. Models and diagnostics for this high performance on water vapor will be discussed