Engineering Commons^™

Development And Testing Of An 8-Bit Digitally Throttled Hybrid Rocket Motor, Trevor W. Coombs

All Graduate Theses and Dissertations, Fall 2023 to Present

Hybrid rocket motors that use a solid fuel grain and liquid oxidizer are low-cost and safer alternatives to traditional rocket motors. Another benefit of hybrid rocket motors is that during a burn, the amount of oxidizer into the combustion chamber can be changed, this capability is called throttling. To take advantage of the throttling ability of hybrid rocket motors, a throttling valve made up of 8 individually controlled valves is designed, developed, and tested, which is documented in this thesis. The results of the testing campaign show that the 8-bit digital throttling valve technology is an effective throttling technology and …

In-Situ Optical Measurements Of High Temperature Combustion Plumes, Cara Frischkorn

All Graduate Theses and Dissertations, Fall 2023 to Present

Rocket motors are critical to the human exploration of space and to the United States missile defense systems. The design and manufacturing of these motors requires extensive simulation and testing to assure the motors will perform as intended and to minimize safety risks. Taking data from inside the rocket motors during tests is extremely difficult due to the intense temperatures inside the motor as it burns; most instrumentation cannot survive in this environment. The research discussed in this thesis aims to develop an instrumentation system composed of a fiberoptic cable which conducts light from the interior of a rocket motor …

Development Of A Potassium Permanganate Catalyst-Infused Fuel Grain For Hydrogen Peroxide Hybrid Thruster Ignition Enhancement, Ryan J. Thibaudeau

All Graduate Theses and Dissertations, Fall 2023 to Present

This thesis describes and addresses the need for reliable ignition in small satellite hybrid propulsion systems using hydrogen peroxide. It describes process of creating custom 3D printed ABS plastic fuel grains with small amounts of catalysts. These catalysts lead to a more reliable and energy-efficient ignition of a hybrid rocked propulsion system using catalyst-infused ABS and high-test hydrogen peroxide (HTP). Hydrogen peroxide is a high-density oxidizer and therefore more volumetrically efficient for a small satellite using hybrid rocket technology when compared to gaseous oxygen (GOX). The traditional ignition methods of hybrid rocket propulsion systems using HTP are compared to and …

Cislunar Navigation Techniques And Navigation Performance Optimization, Quinn P. Moon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nova-C is a lunar lander developed by the private company Intuitive Machines to deliver commercial payloads to the Moon. The IM-1 mission set for 2023 will launch and land the Nova-C near the Moon's south pole. In this research, various navigation techniques are explored to determine the lander's position and velocity during key segments. This process is studied for key mission events including trajectory correction maneuvers (TCMs), lunar orbit insertion (LOI), and descent orbit insertion (DOI). Each mission segment, referred to as an Orbit Determination Segment (OD), is analyzed with three different navigation techniques: Monte Carlo Analysis, Linear Covariance Analysis, …

Low-Erosion Nozzle Materials For Long-Duration Hybrid Rocket Burns, Russell S. Babb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hybrid rocket systems, which employ a solid fuel grain and a liquid oxidizer, are a low-cost and environmentally friendly alternative to traditional rocket systems. However, hybrid rockets suffer from an increased nozzle throat erosion rate, which impacts motor performance and reliability. To address this issue several materials and low-erosion nozzle configurations were tested. The results of the testing campaign produced a nozzle that reduce the throat erosion rate five-fold.

Augmented State Linear Covariance Applications For Nonlinear Missile Engagements, Jeffrey Scott Clawson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sustained actuator saturation is a common occurrence for missile engagements. The saturation nonlinearity creates some difficulty for high-fidelity linear analysis methods. This dissertation investigates three methods of modeling actuator saturation in an advanced linear analysis. The linear covariance tools from this dissertation run extremely fast and provide several advantages over other linear missile engagement analysis methods. First, a simulation is developed and validated for a target engagement scenario without actuator saturation. Next, saturations are introduced to the problem, along with the first analysis method: statistical linear covariance analysis. This method combines the augmented state linear covariance framework with the statistical …

Aerodynamic Implications Of A Bio‐Inspired Rotating Empennage Design For Control Of A Fighter Aircraft, Christian R. Bolander

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation presents an analysis of the aerodynamics for an aircraft using a novel, bio-inspired control system. The control system is a rotating tail, that is inspired by the way in which birds use their tail to control their flight. An aerodynamic model for a baseline aircraft and a bio-inspired variant are created by referencing well-known relationships for the aerodynamics of flight, which are then used to analyze the available flight envelope at which each aircraft can reach two different equilibrium states. An analysis of the total aerodynamic control authority of each aircraft is also included along with a preliminary …

High Efficiency Angles-Only Space-Based Approaches For Geosynchronous Orbit Catalog Maintenance With Sparse Information, Louis M. Tonc

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The thesis of this dissertation proposes a novel filter algorithm to improve tracking and catalog maintenance of uncooperative satellites and other Resident Space Objects (RSOs) in Geosynchronous Equatorial Orbit (GEO). Tracking can be supported by space-based tracking from observer satellites (OBSs). Practical limitations can lead to long time gaps between measurement updates when tracking RSOs from an OBS, which may induce a loss of fidelity or divergence of the estimation algorithm. The Extended Kalman filter (EKF) is commonly used for tracking RSOs but it diverges as a consequence of nonlinearity in the dynamics and nonlinearity in the optical measurements from …

A Theoretical Trade-Off Between Wave Drag And Sonic Boom Loudness Due To Equivalent Area Changes On A Supersonic Body, Nolan L. Dixon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The NASA University Leadership Initiative (ULI) titled ”Adaptive Aerostructures for Revolutionary Civil Supersonic Transportation” consists of a team of university and industry partners studying the feasibility of reducing the perceived loudness of the sonic boom by introducing an adaptive geometry at localized regions of an aircraft’s outer-mold line. The Utah State University AeroLab is a member of this ULI team and has produced low-fidelity tools to predict the aerodynamic and boom loudness effects from localized changes to the geometry.

Such changes to the geometry affect both the sonic boom loudness and wave drag; however, the precise relationship between boom loudness …

Lifting-Line Predictions For Life And Twist Distributions To Minimize Induced Drag In Ground Effect, Kyler Church

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The elliptic lift distribution produces the minimum induced drag for a given wingspan and desired lift outside of ground effect. This distribution can be generated on any wing by using geometric and/or aerodynamic twist. However, in ground effect, the elliptic lift distribution is not necessarily that which minimizes induced drag. The present work uses a modern numerical lifting-line algorithm to evaluate how the optimum lift distribution varies as a function of height above ground. The algorithm is also used to obtain the twist distributions that should be applied to wings of varying aspect ratios and taper ratios to produce the …

Control Mapping Methodology For Tailless Morphing-Wing Aircraft, Zachary S. Montgomery

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Advanced aircraft designs tend to have several control surfaces or devices that affect the flight of the aircraft. It is difficult or even impossible for a pilot to directly control each of these devices and fly the aircraft well. Therefore, a control mapping logic is needed to take typical pilot commands and map them to what the control devices should do to achieve the pilot’s commands. This work presents a methodology for determining this control mapping logic using two different approaches. The first uses a theoretical approach based on lifting-line theory, while the second leverages computational methods. The methodology consists …

Fabrication And Testing Of Catalyst-Infused Filament For 3d Printing Of Ignition-Augmented Hybrid Rocket Fuels, Kurt C. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis describes and addresses the need for reliable ignition in small satellite hybrid propulsion systems using higher density oxidizers. It describes methods of creating custom 3D printing ABS plastic based filaments that contain small amounts of catalysts. These catalysts lead to a more reliable and energy-efficient ignition of a hybrid rocked propulsion system using catalyst-infused ABS and nitrous oxide and oxygen blend called Nytrox, commonly known as ”laughing gas.” The ”laughing gas” has a higher density and can therefore provide more ”miles per gallon” in a hybrid propulsion system on a small satellite when compared to gaseous oxygen (GOX). …

Optimal Relative Path Planning For Constrained Stochastic Space Systems, Nathan Bohus Stastny

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rendezvous and proximity operations for automated spacecraft systems requires advanced path planning techniques that are capable of generating optimal paths. Real-world constraints, such as sensor noise and actuator errors, complicate the planning process. Operations also require flight safety considerations in order to prevent the spacecraft from potentially colliding with the associated companion spacecraft. This work proposes a new, ground-based trajectory planning approach that seeks an optimal trajectory while meeting all mission constraints and accounting for vehicle performance and safety requirements. This approach uses a closed-loop linear covariance simulation of the relative trajectory coupled with a genetic algorithm to determine fuel …

A Study Of Wings With Constant And Variable Sweep For Aerodynamic Efficiency In Inviscid Flow, Bruno Moorthamers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wing sweep has been studied by industry and academia since the pioneering days of aviation for both high-speed and low-speed applications. In transonic and supersonic flight regimes it serves to delay the onset of compressibility effects and decrease wave drag. In subsonic conditions, flying wing designs sweep back the main lifting surface in such a way that it can be used for longitudinal stability and control, to allow for the elimination of a traditional empenage. This is desirable because it can decrease the aerodynamic drag. Sweep can also be seen in nature in the wings of birds and fins of …

Airframe And Systems Design, Analysis, And Testing Of The Horizon Morphing-Wing Aircraft, Sabrina A. Snow

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Morphing trailing edge technology can provide the ability to dynamically alter the twist distribution, and therefore lift distribution, of an aircraft during flight. There are certain optimal lift distributions which can be chosen to create proverse yawing effects and eliminate the need for vertical control surfaces. The purpose of this project is to support the design and testing of a morphing, crescent flying wing airframe which will be used to evaluate yaw control in an aircraft without vertical control surfaces. There are three main objectives of this project, which are to perform static and dynamic analysis on the crescent wing …

Passive Cavity Deflation After Water Entry Facilitated By A Vented Tube, Emma R. Fraley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When an object enters water, a crater, or air cavity, can form around the object and remain attached as the object travels underwater. Cavities can be beneficial and reduce drag force but there may be times when the cavity needs to be removed. This research proposes a method to remove air cavities by letting air leave the cavity, deflating the cavity similar to how a balloon is deflated. To provide air a path to leave the cavity, a tube with vent holes is attached to the object. The vent holes are located near the object, where the air cavity forms, …

3d-Printed Morphing Wings For Controlling Yaw On Flying-Wing Aircraft, Benjamin C. Moulton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The flaps on an airplane wing are used to control the aircraft during flight. These flaps traditionally have at most three articulation or hinge points. Recent studies have shown improved flap efficiency using a conformal flap, which deforms following a curved shape. Much of aircraft improvement comes through increasing its efficiency during flight. This efficiency is generally improved by decreasing the drag force on the aircraft. A potential solution to decrease drag is to remove additional lifting surfaces, such as the horizontal and vertical stabilizer ubiquitous on general aviation aircraft. These additional lifting surfaces are used to trim and control …

Exact And Approximate Relaxation Techniques For Computational Guidance, Sheril Avikkal Kunhippurayil

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The focus of this dissertation is in the development and application of relaxation techniques that enable efficient and real-time solution of complex computational guidance problems. Relaxations transform a non-convex constraint into a convex constraint and provides proof that the optimal solutions to the relaxed problem are optimal for the original problem. Unique contributions of this work include: 1) a relaxation technique for solving fixed final time problems between fixed points, 2) a performance analysis on the application of computational guidance for the Mars Ascent Vehicle, and 3) establishment of sufficient conditions for non-singularity of optimal control for problems on a …

Attitude And Reflection Parameter Estimation Of Resident Space Objects Using Ground-Based Photometry, Arun J. Bernard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

There are currently thousands of objects orbiting Earth, and this number is only going to increase. Larger number of satellites will require that operators have a greater knowledge of the state their assets. Electro-optical telescopes are currently being used to observe and track many of these objects. When using these telescopes to take images of satellites, they often appear as dots in the image. Depending on the surface properties of the satellite, and its orientation at a given time, the dots in the image can appear brighter or dimmer. Photometry measurements are a quantification of how bright the object appears. …

Development Of An Anisotropic Thermal Stress Model For A Low-Erosion Hybrid Rocket Nozzle System, Judson C. Stephens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hybrid rockets are rockets which employ a solid fuel grain with a liquid oxidizer. Hybrids have many promising potential applications, however they also have a few drawbacks. Of interest to this research is the increased rate of nozzle erosion inherent to hybrid rockets. In order to address this issue, a low-erosion nozzle is proposed and evaluated.

Navigation Performance Of Line/Plane Intersection Lidar Model In Conjunction With Opportunistic Feature Tracker, Michael R. Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With NASA awarding numerous contracts to build commercial lunar payload spacecraft and human lunar landers, the need for high precision navigation has increased. Traditional inertial navigation alone is not sufficient to autonomously land a vehicle on hazardous lunar terrain. Terrain relative navigation (TRN) systems have been explored in previous research that exploit camera observations of known landmarks. Such approaches require the flight electronics to correctly match features of the observed landmarks to an onboard database, in the drastically varying lighting conditions of moon. This paper explores the performance of a TRN system that does not rely on apriori landmark identification, …

Sonic Boom Loudness Reduction Through Localized Supersonic Aircraft Equivalent-Area Changes, Troy A. Abraham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The NASA University Leadership Initiative (ULI) titled “Adaptive Aerostructures for Revolutionary Civil Supersonic Transportation” looks to study the feasibility of distributed structural adaptivity on a supersonic aircraft for maintaining acceptable en-route sonic boom loudness during overland flight. The ULI includes a team of industry and university partners that are working together to develop and implement the systems necessary to accomplish this goal.

The Utah State University Aerolab is a member of this ULI team and has been tasked with developing and using low-fidelity supersonic aerodynamic and sonic boom predictions tools to rapidly study the effects of localized geometry changes on …

Computational Fluid Dynamics Benchmark Validation Experiment Of Plenum-To-Plenum Flow Through Vertical Heated Parallel Channels, Austin W. Parker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The next generation of nuclear power plants will have higher efficiency and improved safety, among other benefits; one attractive option is the high temperature gas reactor. An ability to predict the physics that occur within the reactor under normal conditions and accident scenarios is necessary before it receives regulatory licensing for use. The flow through a high temperature gas reactor involves complex interactions of heat transfer, fluids, and solids.

One method for simulating complex fluid dynamics is called Computational Fluid Dynamics. These simulations have already been used to predict the complex fluid flows found in high temperature gas reactors. Predicting …

Sensitivity And Estimation Of Aerodynamic, Propulsion, And Inertial Parameters For Rudderless Aircraft Using Simulation, Jaden W. Thurgood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A technique known as system identification is often used in aircraft design and testing to understand and validate the mathematical parameters that describe the aircrafts stability and handling characteristics. System identification can be thought of as the inverse of simulation. In the world of system identification, we have a physical system that we seek to understand in more detail by monitoring the system with an array of sensors. In short, we conduct tests of an aircraft while recording the inputs and response outputs. Then we take the input and output data and run it through an algorithm that seeks to …

Closed-Loop Propulsive Control For Very Low Perigee Orbit Energy Management And Stabilization, Tyler J. Gardner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Within the past decade, the United States Air Force has begun exploring options for using smaller satellites, known as SmallSats and CubeSats, to decrease the time it takes to design and build new satellites. If used properly, a rapid development environment for satellites could improve the Air Force's ability to respond to new technologies and threats. Other organizations such as NASA and universities have been using SmallSats and CubeSats for research and development missions.

While smaller satellites are usually much cheaper to develop and require less time to create, limited volume strictly constrains the size of instrumentation and avionics that …

Analytic Guidance Strategies For Passively Safe Rendezvous And Proximity Operations, Simon Shuster

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A safety ellipse is a type of relative motion trajectory that is commonly used for unmanned rendezvous and proximity operations. As the name suggests, safety ellipses are passively safe relative motion trajectories, which means that their natural motion inherently maintains a low collision risk. The focus of this dissertation is the derivation, analysis, and application of guidance strategies that reconfigure, establish, and exit a safety ellipse. The guidance strategies consist of a set of ∆v vectors and impulse times, all written in closed form. Through applications of optimal control theory and parameter optimization, it is shown that these maneuver …

A General Approach To Lifting-Line Theory, Applied To Wings With Sweep, Jackson T. Reid

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lifting-line theory is one simple method of predicting the lift produced by a wing. The traditional implementation of lifting-line theory, developed in 1918, is limited to predicting the lift of traditional straight wings. In this work, lifting-line theory is extended to predict the lift produced by modern swept (or "v-shaped") wings by strategically handling the singularities inherent to the theory. The resulting formulation is shown to be both accurate and computationally inexpensive, when compared to experimental and higher-fidelity computational results, demonstrating the method's usefulness as an aerodynamic design tool. Because of the low computational cost and accuracy of the method …

Impact Of Parasitic Drag On A Family Of Optimal Lift Distributions, Austin J. Stewart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Minimizing drag is a variational problem, and several minimum induced drag solutions have been found using different design constraints. The elliptic lift distribution is commonly used to minimize induced drag, but is only the optimal solution under one set of design constraints. Non-elliptic lift distributions are able to reduce induced drag, when compared to the elliptic lift distribution, by increasing the wingspan while maintaining a consistent wing–structure weight. However, these non-elliptic lift distributions are only optimal if the effects of viscous drag are neglected. In this study, numerical tools are used to estimate the total drag on rectangular wings that …

Practical Optical Survey Strategies For Near Geostationary Orbital Debris, Akhter Mahmud Nafi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Uncontrolled space objects, more commonly known as space debris, consist of dead satellites, satellite deployment packages, and lost elements of these systems such as insulation blankets. These uncontrolled objects represent hazards to our nation’s most valuable space assets which include communication satellites, weather satellites, Earth monitoring systems, and military assets. To help mitigate this problem, this research proposes using the known astrodynamics of the near geosynchronous orbit (GEO) along with the known concentration of the uncontrolled GEO objects and observation constraints to design ground-based optical surveys that will detect uncatalogued debris. Furthermore, a scoring metric is developed to evaluate the …

Revolution In Autonomous Orbital Navigation (Raon), Rachit Bhatia

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spacecraft navigation is a critical component of any space mission. Space navigation uses on-board sensors and other techniques to determine the spacecraft’s current position and velocity, with permissible accuracy. It also provides requisite information to navigate to a desired position, while following the desired trajectory. Developments in technology have resulted in new techniques of space navigation. However, inertial navigation systems have consistently been the bedrock for space navigation.

Recently, the successful space mission GOCE used on-board gravity gradiometer for mapping Earth’s gravitational field. This has motivated the development of new techniques like cold atom accelerometers, to create ultra-sensitive gravity gradiometers, …