Cathode erosion is one of the life-limiting mechanisms in several classes of electric thrusters. Since cathode erosion depends strongly on the cathode temperature, a quantitative understanding of the effects of cathode operation in the... more
Cathode erosion is one of the life-limiting mechanisms in several classes of electric thrusters. Since cathode erosion depends strongly on the cathode temperature, a quantitative understanding of the effects of cathode operation in the cathode temperature is required. A pure tungsten cathode was sucessfully operated in an argon discharge at pressures of 1.5 and 3.0 kPa and current levels of 600, 1000 and 1400 A.
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A total of 1462 hours of operaton were demonstrated in an endurance test of a 30 kWe-class ammonia arcjet operated at 10 kWe. The propellant flow rate was 0.170 g/s, and the measured performance increased from approximately 650 s specific... more
A total of 1462 hours of operaton were demonstrated in an endurance test of a 30 kWe-class ammonia arcjet operated at 10 kWe. The propellant flow rate was 0.170 g/s, and the measured performance increased from approximately 650 s specific impulse at 36 percent efficiency at the beginning of the test to 675 s at 39 percent near the end. The voltage increased and the current dropped slightly over the first 400 hours, and then remained approximately constant for the remainder of the test. The test, scheduled for 1500 hours, was terminated after an insulator in the rear of the engine failed. Post-test examination of the electrodes revealed only minimal damage. Although there was evidence of a number of mass transport processes occurring in the discharge chamber, the primary life-limiting wear mechanisms appear to be cathode tip erosion and constrictor melting.
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... 회의장소, Huntsville, AL. 회의기간, 2003/07/20 - 2003/07/23. 주관기관, AIAA. The successful demonstration of ion propulsion on NASA's Deep Space 1 (DS1) mission has stimulated substantial interest in the application of this technology to... more
... 회의장소, Huntsville, AL. 회의기간, 2003/07/20 - 2003/07/23. 주관기관, AIAA. The successful demonstration of ion propulsion on NASA's Deep Space 1 (DS1) mission has stimulated substantial interest in the application of this technology to future solar system exploration missions ...
... The Deep Space One (DS1) mission was launched in October of 1998, on a mission to ... ELT image data and the previous endurance tests, it is known that accelerator grid erosion is ... apparent, and the erosion of the grid webbing had... more
... The Deep Space One (DS1) mission was launched in October of 1998, on a mission to ... ELT image data and the previous endurance tests, it is known that accelerator grid erosion is ... apparent, and the erosion of the grid webbing had begun to manifest itself into the characteristic ...
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Research Interests:
... AlAA Experimental and Theoretical Analysis the Grid Clearing Capability the NSTAR Ion Propulsion System Keith Goodfellow Gani Ganapathi and John Stocky Jet Propulsion Laboratory California Institute Technology Pasadena jfhAIAA ASME... more
... AlAA Experimental and Theoretical Analysis the Grid Clearing Capability the NSTAR Ion Propulsion System Keith Goodfellow Gani Ganapathi and John Stocky Jet Propulsion Laboratory California Institute Technology Pasadena jfhAIAA ASME SAE ASEE Joint Propulsion ...
Design chamclcris(ics ofacryopun~po~)ti\~]i~,d forxc]]on arc])rcscl)tcd. Sin.glc-stagc Gifford-McMahon hcliun~ cryoprrnrps that])rovidc acryc)rcfrigcratiol) capability of105Wat 50Ktochill coldplatcs arcuscd witioulbafflcsto... more
Design chamclcris(ics ofacryopun~po~)ti\~]i~,d forxc]]on arc])rcscl)tcd. Sin.glc-stagc Gifford-McMahon hcliun~ cryoprrnrps that])rovidc acryc)rcfrigcratiol) capability of105Wat 50Ktochill coldplatcs arcuscd witioulbafflcsto cnablclargcpurnp spedsonxcn on. Shrouds arcusti torducc ticthcrt]lal ...
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Page 1. Long Duration Ground Testing of the Deep Space 1 Flight Spare Ion Thrusterthe First 15600 Hours * John R. Anderson, Keith D. Goodfellow and James E. Polk Jet Propulsion Laboratory California Institute of Technology ...
Page 1. q * AIAA-94-2851 Segmented Ion Engine Operation and Performance John R, Brophy*, Jucrgcn Mueller,** Lewis C. Plcss, *** Mike Ticrney~ Keith D. Goaifcllow**, and John R, Anderson** Jet Propulsion Ldoratory Calfornia Institute of... more
Page 1. q * AIAA-94-2851 Segmented Ion Engine Operation and Performance John R, Brophy*, Jucrgcn Mueller,** Lewis C. Plcss, *** Mike Ticrney~ Keith D. Goaifcllow**, and John R, Anderson** Jet Propulsion Ldoratory Calfornia Institute of Technology Pmzicna, California ...
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The MPD thruster program at JPL. John Barnett, Keith Goodfellow, James Polk, Thomas Pivirotto In NASA. Lewis Research Center, Magnetoplasmadynamic Thruster Workshop 12 p(SEE N 92-10044 01-20) 1991, 1991. The ...