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Development of a high power microwave thruster, with a magnetic nozzle, for space applicationsThis paper describes the current development of a high-power microwave electrothermal thruster (MET) concept at the NASA Lewis Research Center. Such a thruster would be employed in space for applications such as orbit raining, orbit maneuvering, station change, and possibly trans-lunar or trans-planetary propulsion of spacecraft. The MET concept employs low frequency continuous wave (CW) microwave power to create and continuously pump energy into a flowing propellant gas at relative high pressure via a plasma discharge. The propellant is heated to very high bulk temperatures while passing through the plasma discharge region and then is expanded through a throat-nozzle assembly to produce thrust, as in a conventional rocket engine. Apparatus, which is described, is being assembled at NASA Lewis to test the MET concept to CW power levels of 30 kW at a frequency of 915 MHz. The microwave energy is applied in a resonant cavity applicator and is absorbed by a plasma discharge in the flowing propellant. The ignited plasma acts as a lossy load, and with optimal tuning, energy absorption efficiencies over 95 percent (based on the applied microwave power) are expected. Nitrogen, helium, and hydrogen will be tested as propellants in the MET, at discharge chamber pressures to 10 atm.
Document ID
Document Type
Conference Paper
Power, John L. (NASA Lewis Research Center Cleveland, OH, United States)
Chapman, Randall A. (NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1989
Subject Category
Report/Patent Number
NAS 1.15:102321
Meeting Information
Microwave Power Symposium(Stanford, CT)
Funding Number(s)
PROJECT: RTOP 506-42-31
Distribution Limits
Work of the US Gov. Public Use Permitted.

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NameType 19890017533.pdf STI