Download or read book A Performance Comparison of Pulsed Plasma Thruster Electrode Configurations written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-09 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulsed plasma thrusters are currently planned on two small satellite missions and proposed for a third. In these missions, the pulsed plasma thruster's unique characteristics will be used variously to provide propulsive attitude control, orbit raising, translation, and precision positioning. Pulsed plasma thrusters are attractive for small satellite applications because they are essentially stand alone devices which eliminate the need for toxic and/or distributed propellant systems. Pulsed plasma thrusters also operate at low power and over a wide power range without loss of performance. As part of the technical development required for the noted missions, an experimental program to optimize performance with respect to electrode configuration was undertaken. One of the planned missions will use pulsed plasma thrusters for orbit raising requiring relatively high thrust and previously tested configurations did not provide this. Also, higher capacitor energies were tested than previously tried for this mission. Multiple configurations were tested and a final configuration was selected for flight hardware development. This paper describes the results of the electrode optimization in detail. Arrington, Lynn A. and Haag, Tom W. and Pencil, Eric J. and Meckel, Nicole J. Glenn Research Center NASA/TM-97-206305, E-11002, NAS 1.15:206305, IEPC-97-127 NAS3-27186; RTOP 632-1B-1B...

Download or read book Carbon Fibers written by Soo-Jin Park and published by Springer. This book was released on 2014-10-08 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains eight chapters that discuss the manufacturing methods, surface treatment, composite interfaces, microstructure-property relationships with underlying fundamental physical and mechanical principles, and applications of carbon fibers and their composites. Recently, carbon-based materials have received much attention for their many potential applications. The carbon fibers are very strong, stiff, and lightweight, enabling the carbon materials to deliver improved performance in several applications such as aerospace, sports, automotive, wind energy, oil and gas, infrastructure, defense, and semiconductors. However, the use of carbon fibers in cost-sensitive, high-volume industrial applications is limited because of their relatively high costs. However, its production is expected to increase because of its widespread use in high-volume industrial applications; therefore, the methods used for manufacturing carbon fibers and carbon-fiber-reinforced composites and their structures and characteristics need to be investigated.

Download or read book Overview of Nasa s Pulsed Plasma Thruster Development Program written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-21 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: NASA's Pulsed Plasma Thruster Program consists of flight demonstration experiments, base research, and development efforts being conducted through a combination of in-house work, contracts, and collaborative programs. The program receives sponsorship from Energetics Project, the New Millennium Program, and the Small Business Innovative Research Program. The Energetics Project sponsors basic and fundamental research to increase thruster life, improve thruster performance, and reduce system mass. The New Millennium Program sponsors the in-orbit operation of the Pulsed Plasma Thruster experiment on the Earth Observing 1 spacecraft. The Small Business Innovative Research Program sponsors the development of innovative diamond-film capacitors, piezoelectric ignitors, and advanced fuels. Programmatic background, recent technical accomplishments, and future activities for each programmatic element are provided. Pencil, Eric J. and Kamhawi, Hani and Arrington, Lynn A. Glenn Research Center NASA/TM-2004-213291, AIAA Paper 2004-3455, E-14738

Download or read book Evaluation of Pulsed Plasma Thruster Micropulsing written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-21 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper evaluates the concept of pulsed plasma thruster (PPT) micropulsing. Micropulsing was a premise behind a power processing unit (PPU) and an energy storage unit (ESU) design that for certain mission profiles, it was advantageous to operate a PPT at lower energy but higher frequency rather than at a higher energy but lower frequency. This premise allows for reductions in the ESU volume and mass without paying a penalty in thrust. To complete the evaluation, an independent spark plug initiation unit, a high voltage power supply and a variety of mica foil capacitors at 2.6, 5, 10, and 20 capacitance were used to conduct a series of tests on a single PPT to map performance levels of thrust, impulse bit, efficiency and specific impulse over a comparable power range. Testing at NASA Glenn Research Center was conducted with breadboard PPT hardware. The test results showed that operating in the lower energy ESU micropulsing mode produced similar thrust levels to a higher energy ESU operating at high power level. Further testing however showed a reduction in specific impulse and efficiency when the smaller capacitances were used at the highest power levels. This would require more fuel mass for a mission that was predominately high power, potentially negating the ESU mass savings. Therefore, micropulsing is advantageous where most of a mission profile occurs at low power, but retains the ability to conduct high thrust maneuvers when necessary. Arrington, Lynn Glenn Research Center NASA/CR-2004-213209, AIAA Paper 2004-3458, E-14717

Download or read book Internal Plasma Properties and Enhanced Performance of an 8 Cm Ion Thruster Discharge written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-15 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a need for a lightweight, low power ion thruster for space science missions. Such an ion thruster is under development at NASA Glenn Research Center. In an effort to better understand the discharge performance of this thruster. a version of this thruster with an anode containing electrically isolated electrodes at the cusps was fabricated and tested. Discharge characteristics of this ring cusp ion thruster were measured without ion beam extraction. Discharge current was measured at collection electrodes located at the cusps and at the anode body itself. Discharge performance and plasma properties were measured as a function of discharge power, which was varied between 20 and 50 W. It was found that ion production costs decreased by as much as 20 percent when the two most downstream cusp electrodes were allowed to float. Floating the electrodes did not give rise to a significant increase in discharge power even though the plasma density increased markedly. The improved performance is attributed to enhanced electron containment. Foster, John E. and Patterson, Michael J. Glenn Research Center NASA/TM-1999-209386, E-11813, NAS 1.15:209386

Download or read book A Hall Thruster Performance Model Incorporating the Effects of a Multiply Charged Plasma written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-19 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Hall thruster performance model that predicts anode specific impulse, anode efficiency, and thrust is discussed. The model is derived as a function of a voltage loss parameter, an electron loss parameter, and the charge state of the plasma. Experimental data from SPT and TAL type thrusters up to discharge powers of 21.6 kW are used to determine the best fit for model parameters. General values for the model parameters are found, applicable to high power thrusters and irrespective of thruster type. Performance of a 50 kW thruster is calculated for an anode specific impulse of 2500 seconds or a discharge current of 100 A. Hofer, Richard R. and Jankovsky, Robert S. Glenn Research Center NASA/TM-2002-211214, E-13066, NAS 1.15:211214, AIAA Paper 2001-3322