Propulsion and Power Commons^™

Low Power Magnetically Shielded Krypton Hall Thruster Design, Grace Klang

Honors Theses

This project investigates the design and modeling of a low-power Hall-Effect Thruster optimized for krypton propellant, serving as a continuation of Western Michigan University’s Hall thruster development series. Krypton is selected as an alternative to xenon due to its significantly lower cost and increased availability, though its higher ionization energy and reduced atomic mass introduce performance, ionization, and efficiency challenges that must be addressed through careful design. The goal of this study is to design two 300-W class thrusters capable of achieving high efficiency and long operational life on krypton propellant while maintaining full compatibility with existing laboratory facilities and …

Design, Optimization, And Initial Results Of An Automatic Impedance Matching Network For Nitrogen Inductively Coupled Plasma, Logan Anthony Alvesteffer

Masters Theses

The electric propulsion industry is witnessing a strategic interest toward the utilization of molecular propellants as alternatives to noble gases due to increasing cost constraints and logistical requirements. This transition is hindered by a fundamental deficiency in the understanding of molecular plasma and radio frequency physics, including the excitation, dissociation, and ionization cross-sections, which mandates a reliance on computationally inefficient, empirically modified atomic thruster designs. Furthermore, current state-of-the-art electric propulsion devices, such as gridded ion thrusters and Hall effect thrusters, utilize an electrode (cathode) for ionization and are thus susceptible to chemical poisoning and material erosion, which is prevalent while …

Analysis Of The Effects Of Extractor Orientation On The Performance Of An Electrospray System, Hannah Grace Sargent

Masters Theses

In this thesis, a single-emitter porous electrospray thruster was tested at nine different extractor electrode positions. The nine positions were: center, four slightly offset in each cardinal direction, and four significantly offset in each cardinal direction. Slightly offset was defined as ~25% of the distance from the center to the edge of the extractor orifice (~125 ± 2 μm) and significantly offset was defined as ~60% of the distance from the center to the edge of the extractor orifice (~302 ± 2 μm). Three diagnostic measurements were recorded to determine the effect of the extractor electrode position on thruster operation: …

Emission Behavior At The Single Emitter Scale From A Porous Media Ionic Liquid Ion Source, Thomas Victor Kerber

Dissertations

Ionic liquid ion sources (ILIS) are being developed as one solution to fill a technology gap in low power, high efficiency, high specific impulse space propulsion systems. With a sufficiently intense electric field applied between an emitter electrode and an extractor electrode, charged particles are extracted from the fluid surface and accelerated out of the thruster. In this work, three experimental campaigns examine emission behavior of a single emitter ILIS made of porous material that allows passive propellant feed via capillary action of the ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF₄).

Repeated measurements of the emitter and extractor current as …

Turbulence And Energetic Ion Production In The Partially Magnetized Hollow Cathode Plume, Margaret Mary Mooney

Dissertations

Hall effect thrusters (HETs) are the most widely used electric propulsion (EP) device for in-space satellite propulsion. EP devices provide high efficiencies for extended mission lifetimes and low thrust for precision maneuvers. The hollow cathode is a critical HET component and undergoes extensive lifetime testing in addition to the lifetime testing of the full HET. Significant density gradients, non-Maxwellian electron behavior, and magnetic fields sufficiently strong enough to magnetize electrons in hollow cathode plumes create favorable conditions for the formation of plasma instabilities, which have an impact on cathode lifetime. Cathode qualification testing is typically conducted independently and includes a …

A Model For Spacecraft Relative Motion Using Continuous Periodic Thrust, Philip Alan Hittepole

Dissertations

A model for modifying the relative orbit of a deputy satellite with respect to a chief satellite in a near-circular orbit using continuous periodic thrust is presented. This model is built on the Lovell-Spencer relative orbital elements (ROEs). The four linear ROEs (xr, yr, ar, and Az) can be linearly modified. The two angular ROEs (Er and ) can be set to advance at a desired, constant rate. Each ROE can be modified individually but may cause intra-orbit variations in other ROEs which return to their original values at the end of a thrust cycle. A method to easily calculate …

The Design And Development Of A Miniature Gridded Ecr Ion Thruster, Nicholas Nuzzo

Masters Theses

Plasma propulsion, a specific subset of electric propulsion (EP), is a class of space propulsion that produces plasma by excitation of a propellant at or above its ionization energy. This ionized propellant is then accelerated by an externally applied field (magnetic and/or electric) and produces thrust. There is an increasing need for miniaturization in spacecraft technology and the use of plasma EP devices in space propulsion. These systems provide an advantage over traditional chemical propulsion solutions which are less efficient and have more mass. Miniaturization of EP devices allows missions to have more space and mass available for their payloads …

Development Of A Single Emitter Ionic Liquid Ion Source Research Platform, Thomas V. Kerber

Masters Theses

A single emitter ionic liquid ion source using porous borosilicate glass was developed. Two emitters with different radii of curvatures were tested using 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF₄). I-V curves of the currents on the extractor electrode and a collector plate were obtained for potential differences between the emitter and the extractor ranging from 0 V to 3500 V. For the first emitter chip, extraction began near 2400 V. The highest emission current measured on the first chip was 80 µA at 3500 V with an interception current on the extractor of 4.86 µA. An new collector plate was used …

Investigating Newly Discovered Oscillation Modes In Magnetically Shielded Hall Effect Thrusters Utilizing High Speed Diagnostics, Matthew Joseph Baird

Dissertations

Magnetically shielded Hall effect thrusters (MSHETs) are a variant of Hall effect thrusters (HET) that provide the favorable thrust-to-power ratio and high specific impulse of traditional stationary plasma type (STP) HETs but with an extremely long lifetime. MSHETs exhibit unique discharge plasma oscillations compared to traditional unshielded HETs. In this study, measurements of plasma oscillations in the state-of-the-art 12.5 kW Hall Effect Rocket with Magnetic Shielding (HERMeS) were obtained at various discharge voltages while holding other operation parameters constant. Data were collected using high-speed imaging, voltage, current, and plasma probes. The thruster exhibits two dominant oscillation modes within the discharge …

Design Of A Thrust Stand For Electric Propulsion, Hannah Watts

Honors Theses

Thrust stands are the industry standard device for measuring the low levels of thrust generated by electric propulsion devices. Western Michigan University’s Aerospace Laboratory for Plasma Experiments is home to several electric propulsion devices and is in the process of obtaining a pulsed plasma thruster in partnership with the Western Aerospace Launch Initiative. The lab currently has no way of measuring the true thrust force generated by these devices. A thrust stand has been designed specific to the micro-Newton thrust range and the constraints inherent to the facilities in which it will operate.

Localization And System Identification Of A Quadcopter Uav, Kenneth Befus

Masters Theses

The research conducted explores the comparison of several trilateration algorithms as they apply to the localization of a quadcopter micro air vehicle (MAV). A localization system is developed employing a network of combined ultrasonic/radio frequency sensors used to wirelessly provide range (distance) measurements defining the location of the quadcopter in 3-dimensional space. A Monte Carlo simulation is conducted using the extrinsic parameters of the localization system to evaluate the adequacy of each trilateration method as it applies to this specific quadcopter application. The optimal position calculation method is determined.

Furthermore, flight testing is performed in which real range measurement data …