Download or read book Plume Characterization of a One Millipound Solid Teflon Pulsed Plasma Thruster written by L. C. Pless and published by . This book was released on 1978 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: An evaluation was made of the pulsed plasma thruster plume-wall backscatter characteristics of the MOLSINK facility. On the thruster axis, this backscatter drops off to zero as the angle between the axis and wall location reaches 40. This wall backscatter was found to be essentially symmetric about the plume axis. The total integrated backscatter from the MOLSINK wall is approximately equal to 5% of the total mass injected from the pulsed plasma thruster during the discharge pulse.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1982 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 1048 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government reports annual index written by and published by . This book was released on 199? with total page 1314 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1979 with total page 1324 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pulsed Plasma Space Experiment Study written by Dominic J. Palumbo and published by . This book was released on 1982 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study was carried out to determine an appropriate space experiment for the millipound pulsed plasma thruster. The objectives of the experiment were: (1) Verification of ground based measurements related to thruster performance, plume and plume effects characterization, and electromagnetic compatibility; (2) Make such measurements that cannot be accurately made in ground based facilities; (3) Demonstrate the operation of the PPT in the space environment and its compatibility with typical space craft systems. Three vehicle options were considered in the study, and a cost analysis based on 1981 dollars was carried out. (Author).

Download or read book Electric Propulsion and Its Applications to Space Missions written by Robert C. Finke and published by . This book was released on 1981 with total page 896 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1980-10 with total page 1512 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Solid Teflon Pulsed Plasma Thruster written by Robert Vondra and published by . This book was released on 1970 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Assessment of the Plume Characteristics of a Miniaturized Pulsed Plasma Thurster written by Richard Henry [Verfasser] Sypniewski Jr. and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulsed Plasma Thrusters are one of the most simplistic constructions in the electric propulsion family and are categorized among the electromagnetic class of thrusters. This classification of electromagnetics deals with the underlying physics of the pulsed plasma thruster and is much more complex with less understanding then other electric propulsion systems. However, due to the mechanical simplicity, wide range of specific impulses, non-toxic propellant, and the numerous applications, these thrusters are an ideal candidate for integrating into CubeSats. CubeSats are nanosatellites that are designed in three typical standard sizes (1 Unit, 2 Unit, and 3 Unit), each with standardized footprints. The smallest volumetric dimensions are the 1 Unit CubeSat, which is 10 x 10 x 10 cm. The volume and mass of CubeSats are quite small and therefore the miniaturization of the Pulsed Plasma Thruster is necessary to adhere to these constraints. Current research has shown that when miniaturization of a Pulsed Plasma Thruster there is a tendency for the thruster to work and perform in the electrothermal regime rather than in the electromagnetic one. Understanding which regime the thruster is operating in is critical for understanding how to optimize the design. For example, a thruster operates with higher efficiencies in the electromagnetic regime because there is much less loss from Ohmic heating. Preliminary testing of the Micro-Pulsed Plasma Thruster design was performed by the research company called FOTEC and determined a thruster chamber design. To understand thoroughly the Micro-Pulsed Plasma Thruster, characterization of the thruster and its plume will be conducted experimentally. This characterization will determine parametric features such as current/voltage waveform, electron temperatures, electron densities, and exhaust velocities. Performing the initial characterizations will give insight into the Micro-Pulsed Plasma Thruster and will provide further understanding into the regime that the thruster is operating in. The characteristics that resulted from this thesis concluded that the Micro-Pulsed Plasma Thruster is operating in the electromagnetic regime. This was concluded based on several characteristic traits that only conclude for electromagnetic acceleration mechanisms. These were that the peak currents reached were approximately 5,000 A and the exhaust velocity was in the 50 km/sec range. Further information was measured and the total resistance and inductance was calculated to be 13 m and 24 nH. Details on this information and how it was calculated is discussed in this thesis.*****Pulsed Plasma Thrusters are one of the most simplistic constructions in the electric propulsion family and are categorized among the electromagnetic class of thrusters. This classification of electromagnetics deals with the underlying physics of the pulsed plasma thruster and is much more complex with less understanding then other electric propulsion systems. However, due to the mechanical simplicity, wide range of specific impulses, non-toxic propellant, and the numerous applications, these thrusters are an ideal candidate for integrating into CubeSats. CubeSats are nanosatellites that are designed in three typical standard sizes (1 Unit, 2 Unit, and 3 Unit), each with standardized footprints. The smallest volumetric dimensions are the 1 Unit CubeSat, which is 10 x 10 x 10 cm. The volume and mass of CubeSats are quite small and therefore the miniaturization of the Pulsed Plasma Thruster is necessary to adhere to these constraints. Current research has shown that when miniaturization of a Pulsed Plasma Thruster there is a tendency for the thruster to work and perform in the electrothermal regime rather than in the electromagnetic one. Understanding which regime the thruster is operating in is critical for understanding how to optimize the design. For example, a thruster operates with higher efficiencies in the electromagne

Download or read book Pulsed Plasma Thruster Plume Characterization of Ion Species Using a Gridded Energy Analyzer written by Krystal Marie Parker and published by . This book was released on 2002 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spectroscopic Emission Measurements of a Pulsed Plasma Thruster Plume written by and published by . This book was released on 1997 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The optical emission spectra of plasmas produced by a Teflon (polytetrafluoroethylene (PTFE)) solid propellant pulsed plasma thruster (XPPT-1) were measured and analyzed. A broad temporally and spatially integrated survey of the emission from 3500 to 7500 angstrom is reported. It is shown that in the PPT discharge energy range surveyed (15 to 45 joule), the species formed do not vary; that is, no new species are formed as the discharge energy is increased. Furthermore, relative line ratios do not vary significantly with energy, suggesting that the bulk thermodynamic properties of the discharge plasma may not be affected by changing the initial stored capacitor energy. A spatially integrated but time- resolved measurement was carried out which shows the single species emission as a function of PPT discharge time. The magnitude of the emission was found to track closely with the PPT current and depend on the discharge energy. Relative line emission intensities are used to determine the degree of excitation equilibrium and establish bounds on the plasma temperature. Spatially and temporally resolved images are used to estimate the plasma streaming velocity from time-of-flight and Doppler-shift techniques.

Download or read book Experimental and Theoretical Analysis of Pulsed Plasma Exhaust Plumes written by Dominic J. Palumbo and published by . This book was released on 1978 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulsed plasma plume diagnostic studies performed in the past have shown that considerable uncertainty exists because of the degree of backscatter encountered in ground test facilities. The large level of backscatter is attributable to the extremely high mass expulsion rate characteristic of solid propellant pulsed plasma thrusters (30 to 40 g/s on the average). The study reported upon herein had the objective of obtaining a suitable analytic model and computational scheme for calculation of the plume characteristics of a 23 mN-s pulsed plasma thruster. The calculated results were compared to experimental measurements of electron number density and temperature, obtained using specially designed Langmuir probes, only up to the point in the time when backscatter of plume effluents off the vacuum chamber walls became significant. A secondary objective of the program was to design a suitable driver circuit for the Langmuir Sangmuir probes so that a voltage ramp could be pulsed for one microsecond at any given time subsequent to thruster discharge initiation and the volt-ampere characteristic could be displayed on an XY oscilloscope.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1981 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of a Pulsed Plasma Thruster Plume Using a Quadruple Langmuir Probe Method written by N. A. Gatsonis and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pulsed Plasma Plume Studies written by William J. Guman and published by . This book was released on 1977 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exhaust plume of a millipound thrust level pulsed plasma thruster was studied in a vacuum chamber having all walls cooled by liquid nitrogen. This thruster has a propulsive performance capable of meeting North-South station-keeping requirements of satellites. The major source of contamination of a surface located in the facility was identified to be mainly due to mass being scattered off the walls of the test facility because the walls were incapable of absorbing the highly energetic plume of the first encounter with the wall. By means of a Langmuir probe, calorimetric discs, a collimated QCM and collimated glass capture cups it was found that the transient plume is fairly well collimated and that the outer extremities of the plume are located within + or - 30 degrees to + or - 40 degrees with respect to the geometric center line of the thruster that was studied. Whether or not major changes of the exhaust cone would change this location was not examined. Time resolved studies of the plume by a Langmuir probe and a photocell has shown the life of the plume at a region in space to be only a few tens of microseconds. This result reveals that a spacecraft surface exposed over a 5 to 7 year period to the plume of a North-South station keeping thruster will actually see an accumulated plume flow time for only about 5 minutes during that mission time.

Download or read book Pulsed Plasma Propulsion Technology written by Dominic J. Palumbo and published by . This book was released on 1977 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: A pulsed plasma thruster system delivering one millipound of thrust at a sustained firing rate of .16 Hz and specific impulse of 1620 seconds was developed, designed, fabricated, and tested for a total of 12,183 pound-seconds (55, 714 Newton-seconds) of total impulse prior to voluntary shut-down of the test. The system utilizes high energy density 40 Joules/pound (81.7J/kg) KF-film capacitors and a completely packaged bread-board power converter. A total impulse capability of 37,500 pounds-seconds (166, 810 Newton-seconds) was designed into the system and the resulting 23.44 pounds (10.63 kg) of solid Teflon propellant is stored in the shape of a helical coil having an outside diameter of 17.32 inches (44 cm) and overall height of 6.25 inches (15.88 cm). The system was refurbished after completion of the endurance test so that the total compliment of propellant could be restored and run to complete depletion at the AFRPL during their in-house endurance test. This report describes in detail the system and results of endurance testing at Fairchild Republic Company. (Author).