We present a non-dimensional gas-fed pulsed plasma thruster performance model. The analysis uses a circuit element discharge description and a snow-plow mass accumulation model with two non-dimensional parameters for an outer electrode geometry contour and an exponential mass distribution. Implementing a non-dimensional scheme is shown to reduce the number of free parameters in the equations fr...

We report the use of cavity ring-down spectroscopy (CRDS) as a diagnostic tool to study sputter erosion of the VHITAL (Very High Isp Thruster with Anode Layer) thruster. The lifetime of the VHITAL thruster is largely governed by sputter erosion of guard-rings and other critical components. The CRDS technique will be used to measure sputtered molybdenum in the plume of the thruster for various t...

A systems-level trade study is presented comparing the propulsion requirements and associated Ž nal masses for different architectural implementations of the Terrestrial Planet Finder mission. The study focuses on the millinewton-level propulsion chores associated with rotating and repointing an array.Three interferometer conŽ gurations, free  ying, monolithic, and tethered, lead to estimates ...

MIT's fully kinetic particle-in-cell Hall thruster simulation is adapted for use on parallel clusters of computers. Significant computational savings are thus realized with a predicted linear speed up efficiency for certain large-scale simulations. The MIT PIC code is further enhanced and updated with the accuracy of the potential solver, in particular, investigated in detail. With parallelizat...

Hall Effect Thrusters (HET) are known to exhibit many high-speed oscillations that are indicative of thruster performance. Azimuthal ionization oscillations, called spokes, have been investigated extensively but the mechanisms governing their behavior are still poorly understood. Most experimentation has been done with single-channel Hall thrusters but evidence exists that a nested-channel Hall...

A novel thruster fault diagnosis and accommodation method for open-frame underwater vehicles is presented in the paper. The proposed system consists of two units: a fault diagnosis unit and a fault accommodation unit. In the fault diagnosis unit an ICMAC (Improved Credit Assignment Cerebellar Model Articulation Controllers) neural network information fusion model is used to realize the fault id...

Optical emission spectroscopy is employed to correlate BN insulator erosion with highpower operation of the NASA 300M Hall-effect thruster. Actinometry leveraging excited xenon states is used to normalize the emission spectra of ground state boron as a function of thruster operating condition. Trends in the strength of the boron signal are correlated with thruster power, discharge voltage, disc...

Over the last decade, miniature ion thruster development has remained an active area of research do to its low power, low thrust, and high efficiency, however, due to several technical issues; a flight level miniature ion thruster has proved elusive. This thesis covers the design, fabrication, assembly, and test of an altered version of the Miniature Xenon Ion thruster (MiXI), originally develo...

MIT's fully kinetic particle-in-cell Hall thruster simulation is adapted for use on parallel clusters of computers. Significant computational savings are thus realized with a predicted linear speed up efficiency for certain large-scale simulations. The MIT PIC code is further enhanced and updated with the accuracy of the potential solver, in particular, investigated in detail. With parallelizat...

Charge neutralization of an In-FEEP thruster was demonstrated with three different electron sources by zeroing the floating potential of the thruster and neutralizer system. The three cathodes used in the investigation include a mixed metal thermionic cathode, a carbon nanotube field emission cathode, and a Spindt-type Mo field emission array cathode. The field emission cathodes significantly i...