Aerospace Engineering Commons^™

Linking Molecular Structure Evolution To Mechanical Degradation During Environmental Aging In Conventional And Recyclable Epoxy Systems, Ben T. Jewell

Dissertations, Master's Theses and Master's Reports

The long-term performance of polymeric materials in extreme environments is governed by complex chemical and physical aging processes that alter their molecular structure and mechanical integrity. Conventional thermoset epoxies, while widely used in structural applications, are particularly susceptible to oxidative degradation at elevated temperatures, leading to embrittlement and loss of structural integrity. In the first part of this work, diffusion-limited oxidation (DLO) in a bulk structural epoxy was systematically investigated to establish the link between heterogeneous microstructural evolution and macroscopic mechanical degradation. High-temperature oxidation experiments were conducted in a controlled environmental chamber, and the resulting chemical, thermal, and mechanical changes …

Lunar Refueling: Legal Issues And Suggested Solutions, Francesca Giannoni-Crystal

Journal of Law and Mobility

The establishment of settlements and economic activities on the Moon is expected to occur in the near future, positioning the Moon as a critical hub for continued exploration of the Solar System. Central to this development is the creation of a lunar refueling industry, which will play a pivotal role in supporting lunar activities and fostering further exploration.

Lunar refueling, which includes extracting local resources like lunar ice water to obtain hydrogen, offers key benefits, such as reducing the need for resupply missions from Earth, lowering launch costs, extending mission capabilities, and enabling launches from the Moon, which are more …

Little Problems: Photosynthetic Textile Treatments As A Source Of Oxygen, Morgan Campbell

Open Access Master's Theses

During human space travel, oxygen (O2) must be stored and carried aboard the shuttle for the entire journey; compressed O2 is highly flammable and combustible, thus doing so puts the crew’s lives at risk in the event of a fire (Mandel, 2019). By creating O2 onsite, the necessity of compressed O2 canisters and the associated risks can be reduced or erased entirely. Photosynthesis, the process through which plants convert atmospheric carbon dioxide (CO2) into O2, is one method of creating O2 (Lorch, 2020). The National Aeronautics and Space Administration (NASA) has experimented with photosynthetic O2 systems since its inception but …

Man On Mars: How Can International Space Law Limit The Environmental Consequences Of The Coming Rush For Resources In Space, Elizabeth Anne Henderson

Michigan Journal of International Law

The body of international law governing space has stood at a standstill for decades. The five central treaties regulating this area of law are not only vague, but they have also become a hindrance to the global community’s ability to address the rapidly intensifying second space race. The treaties do not adequately state who space belongs to, who is entitled to take advantage of the natural resources of celestial bodies, or what protections are afforded to celestial environments in the face of impending mining and resource extraction projects. This impasse within international law has not stopped entrepreneurs and corporations from …

Drag Reduction In Ground Vehicles Using A Model Porous Medium, Abdullah Ikram Nabi

Master’s Theses

This research investigates aerodynamic drag reduction on a 25° Slanted Ahmed Body (SAB) by integrating porous media model rods through combined experimental and computational methods at a Reynolds number of 1.16×10⁴. Two porous media configurations: short rods (6.75% of the model height) and long rods (20.0% of the model height), both featuring cylindrical rods with 80% porosity, were systematically compared against a baseline SAB. In-depth analyses were performed to investigate the wake flow topology, recirculation region characteristics, pressure coefficient distribution, Reynolds stress distributions and drag coefficient. Experimental investigations employed particle image velocimetry for precise flow visualization, while Reynold Averaged Navier-Stokes …

Investigation Of Subsurface Thermal Radiation Phenomena In Fibrous Thermal Protection Systems, Colby L. Gore

Theses and Dissertations--Science, Technology, Engineering, and Mathematics (STEM) Education

Atmospheric re-entry induces intense thermal stress upon vehicles through a high-enthalpy boundary layer that encompasses the craft. To protect these vehicles, numerous insulative methods, known as thermal protection systems (TPS), are deployed to protect the craft during re-entry. The TPS materials insulate the craft from intense thermal transmission that would terminate a mission. In hypersonic environments, vast temperature gradients exist, enforcing the exponential effect of thermal radiation. However, TPS materials are commonly low-density fibrous materials that allow for the potential to be penetrated by thermal radiation. A series of arc-jet tests was completed to replicate enhanced radiative conditions in a …

Physics-Informed Neural Network Based Aerodynamic Modeling Framework, Nathaniel E. Michek

Graduate Theses, Dissertations, and Problem Reports (ETD)

Significant advances have been made in developing aerodynamic models over the years. While these advances span many modeling techniques and data collection methods, certain aerodynamic regimes still pose significant challenges. These regimes commonly occur when an aerodynamic body is under extreme flight conditions. Many of these conditions occur simultaneously in the rare and poorly understood case of a tumbling aerodynamic body. The flight of a tumbling aerodynamic body goes through the entire range of aerodynamic angles, alpha and beta, causing significant non-linearities and time-dependent effects associated with flow separation. During tumbling, the aerodynamic body simultaneously rotates about all three axes …

End-To-End Neural Network Based Optimal Control For Asymmetric Quadrotor Uas, Ross O'Hara

Graduate Theses, Dissertations, and Problem Reports (ETD)

This thesis presents the development and evaluation of a neural network-based optimal controller for asymmetrically loaded quadrotor unmanned aerial systems (UAS). Traditional control strategies such as PID are typically designed under symmetry assumptions and often degrade in performance when faced with significant loading asymmetries. To address this, a six-degree-of-freedom quadrotor model incorporating rotor dynamics and center-of-mass offsets was developed. A trajectory optimization framework using MATLAB’s fmincon solver generated over 50,000 energy-optimal trajectories across symmetric and asymmetric conditions. These were used to train a range of feedforward neural network architectures in a full-factorial study.

The best-performing controller was identified, having five …

Deep Target Recognition: Semi-Supervised Annotation, Sensor Fusion And Super-Resolution, Shoaib Meraj Sami

Graduate Theses, Dissertations, and Problem Reports (ETD)

Despite the recent expansion of machine learning algorithms to cover a wide range of disciplines, several areas of automatic target recognition (ATR) remain underexplored. This dissertation presents tools developed to improve performance in three significant aspects of ATR: semi-supervised annotation, sensor fusion, and image super-resolution. The aim of the semi-supervised methods is to automatically annotate targets in scenarios where labeled data are scarce in the target domain but available in the source domain. Secondly, to address the limitations of individual image sensors and enhance robustness under different environmental conditions and man-made constraints, a sensor fusion algorithm was developed to improve …

Parameter Estimation Of A 100 Seater Simulated Passenger Aircraft, Michael James Winston

Graduate Theses, Dissertations, and Problem Reports (ETD)

Virtual flight test aircraft provide good opportunities to test new parameter estimation methods. However, good estimates for the parameters in VIRTTAC Castor, a virtual test aircraft, are unavailable. This thesis uses two well-established time domain methods, the Output Error Method and the Filter Error Method, to estimate the parameters of VIRTTAC Castor. Three standard maneuvers were used: Elevator 3-2-1-1, Rudder Doublet, and Aileron Multi-Step. The parameters were estimated across three different flight conditions: weight, altitude and air speed, which resulted in 27 tests for each maneuver. All parameters, and standard deviations estimated are included in the appendix as a table.

Implementation Of A Neural Network Execution Framework For Generalized And Cross-Platform Deep Learning Deployment And Inference On Spacecraft Systems, Rafael Polanco Segovia

Graduate Theses, Dissertations, and Problem Reports (ETD)

Recent advances in hardware and software technology have made it possible to implement more resource-demanding deep learning algorithms in constrained hardware environments. This creates opportunities to use deep learning for aerospace applications on increasingly smaller aerospace vehicles. This work presents the implementation of a Neural Network Execution Framework (NNEF), which aims to provide a cross-platform and reusable framework to deploy and execute trained neural networks for deep learning aerospace applications. The NNEF executes any neural network inference process regardless of the original deep learning framework in which it was created, for supported flight software platforms, and space-like computer boards. Users …

Qualitative Analysis Of Surface Modification On Wiffleball Aerodynamics, Cole Lanni

Williams Honors College, Honors Research Projects

This project investigated how surface modifications to a Wiffleball affect its aerodynamic behavior, particularly its vertical and horizontal movement when thrown. The study tested the hypothesis that altering surface texture through cutting or sanding would influence airflow and pressure differentials, thereby changing the ball's movement. Six ball conditions: including unmodified, sanded, and various cut patterns were tested using a pitching machine in a controlled indoor environment. Each variation was pitched ten times, and movement was analyzed through measurements of contact points on posterboards and performing statistical testing, specifically ANOVA with Post Hoc analysis. Results indicated that surface modifications significantly increased …

Design Of An Active-Control Pressure Regulator For A Rocket, Seth Arkwright

Williams Honors College, Honors Research Projects

An electronically actuated pressure-regulation valve and controller are necessary for maintaining pressure levels in a pressure-fed liquid-fueled rocket engine. Mechanical regulators are too heavy and have unacceptably high-pressure variation throughout the operation of a dynamic system like a rocket. Developing an electronic pressure regulator using a PID controller is a method by which a reliable, accurate, and lightweight flow regulator can be built for use on a rocket vehicle. This work will outline the development of flow simulations, PID controller, physical valve hardware, and initial testing.

Smart Material Actuated Flap, James Lyons, Kristofer Johnson

Williams Honors College, Honors Research Projects

The objective of this project is to develop and evaluate a smart material actuated aerodynamic control surface to determine the viability of these new systems as alternatives to conventional electromechanical and hydraulic systems. The research will begin with the selection of a control surface and actuator design. The concept will then be tailored to create an experimental model for the purposes of this project. Smart materials that suit the model requirements will be selected and procured. Next, the actuators will be shape trained and characterized to meet the model requirements. Then, a benchtop model will be produced for design verification, …

Hot Staging Module For Multistage Rockets, Nanami Whitman, Daniel Montano-Lobe

Williams Honors College, Honors Research Projects

Historically, the Akronauts Rocket Design Team builds and launches two-stage rockets that rely on black powder charges as a way of stage-separation. With a hot-staging module, the second stage is ignited while still connected to the first stage, and the thrust from the second stage induces separation. To prevent rotation of the sustainer during the booster stage, the sustainer motor and fins will be axially interlocked with the module in a similar manner to the Akronauts’ previous stage separation modules. This method would reduce the number of failure modes and reduce the number of components required for stage separation. This …

Vector Estimation For Continuous Tracking Of Observed Radio Signals (V.E.C.T.O.R.) Lunar Navigation System, Dimitry Melnikov, Evan Bartel, Andrew Burrier, Goran Gjorgievski

Williams Honors College, Honors Research Projects

NASA's Artemis program requires precise navigation capabilities to establish the first sustained presence on the lunar surface. However, as launches bring necessary orbital infrastructure, the Artemis program will face a critical period during which reliable lunar navigation is not possible. To address this challenge, the V.E.C.T.O.R. system tracks assets, such as rovers and astronauts, as User Terminals relative to a pre-existing cell tower, or Base Station. To do so, the system leverages existing Base Station hardware to calculate the location of User Terminals in conjunction with existing communications infrastructure.

Effects Of Changes In Strouhal And Reynolds Numbers On Beetle Wing Aerodynamics, Keith L. Thiha

Honors Undergraduate Theses

Insect flight has long been a subject of interest across the scientific community, largely due to the exceptional aerodynamic performance insects demonstrate relative to their size. Insects tend to have very high aerodynamic performance characteristics like thrust and lift generation compared to their size. This has many potential applications in improving aircraft performance, however the flow phenomena concerning insect wing aerodynamics is still an area of ongoing research. This study aims to investigate how variations in key nondimensional flow parameters—specifically the Reynolds number and Strouhal number—affect the aerodynamic performance of beetle wings. Strouhal numbers ranging from 0.2 to 0.6 were …

Mechanical And Thermal Characterization Of Additively Manufactured Carbon/Nylon 12 And Carbon/Peek Composites, Matik Heskin, Bradley Deuser, Thomas P. Schuman, K. Chandrashekhara, John Bayldon, Jeff Degrange, Steven Patterson, Neiko Levenhagen

Chemistry Faculty Research & Creative Works

This study explores additive manufacturing of carbon fiber-reinforced thermoplastic composites using the Composite-Based Additive Manufacturing (CBAM) process. Carbon/Nylon 12 and Carbon/PEEK composites were fabricated and evaluated through mechanical (compression, tensile, flexural, and impact) and thermal (DSC and TGA) tests. Carbon/PEEK exhibited superior mechanical performance, with 97.5% higher tensile strength, 79.8% higher elastic modulus, and 59.6% higher flexural strength compared to Carbon/Nylon 12. Thermal testing showed that Carbon/PEEK had higher thermal stability, beginning degradation at 350 °C versus 298 °C for Carbon/Nylon. These results indicate that CBAM-fabricated Carbon/PEEK composites are suitable for applications requiring high strength and temperature resistance.

Improving The Accuracy Of Neighborhood Median Pixel Method (Nmpm) In Classifying Landsat-8 Oli Images By Optimizing The Scoring System’S Point Values, Abraham T. Magpantay, Proceso L. Fernandez Jr

Department of Information Systems & Computer Science Faculty Publications

The Neighborhood Median Pixel Method has previously been introduced as an image processing technique in remote sensing, developed to classify Landsat-8 OLI satellite image pixels into categories of vegetation, water, and built-up areas. This method relies on a lookup table based on the median pixel values within a pixel’s neighborhood and a scoring system that assigns point values for classification. While a 9x9 neighborhood size was originally proposed, a succeeding study suggested a 13x13 neighborhood for better classification accuracy. This study focuses on refining the scoring system used in the Neighborhood Median Pixel Method, particularly the original set of arbitrary …

Characterization Of Krypton Performance In A Laboratory 300 W Magnetically Shielded Hall-Effect Thruster, Jacob Henry Knott

Dissertations, Master's Theses and Master's Reports

Xenon has long been the propellant of choice in Hall Thrusters; however, significant work has been performed to produce thrusters capable of utilizing alternate propellants due to xenon’s price and scarcity. Krypton is the most similar alternative propellant to xenon. This work examines the performance of a sub-kilowatt magnetically shielded Hall Thruster operating on both xenon and krypton. Krypton produced lower thrust, specific impulse, and was less efficient than xenon. Specifically, the absolute xenon-krypton efficiency gap was 6 to 24 % . Krypton’s inferior efficiency is primarily attributable to differences in mass utilization and beam divergence losses. The impacts of …