Aerospace Engineering Commons^™

Analyzing Micrometeoroid And Orbital Debris Shield Performance For Sample Return Spacecraft, William P. Schonberg, Michael Squire

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Sample-return missions typically seek to collect and return samples from extraterrestrial locations to Earth for analysis. The return of samples from certain locations in the solar system represents a potential hazard to Earth's biosphere from foreign microorganisms. One way this could occur would be a break-up of the returning capsule during entry (which would disperse the samples through the air) due to undetected damage to the capsule thermal protection system (TPS). As a result, missions that plan to return payloads from some destinations are likely to have certain design requirements for the TPS surrounding their returning capsules, which may include …

Reduced Set-Shifting Processing Speed In Male Rats Following Low Dose (10 Cgy) Proton Exposure, Hui Ho Vanessa Chang, Gyutae Kim, Kyu-Sung Kim, Richard A. Britten

Center for Integrative Neuroscience and Inflammatory Diseases (CINID) Faculty Publications

Space radiation (SR) exposure poses significant biomedical risks, including effects on the central nervous system (CNS). These risks are particularly relevant to cognitive function during long-duration space missions. One critical cognitive skill is decision-making, which requires attentional set-shifting (ATSET)—the ability to quickly assess problems, evaluate options, and select the best actions. Previous studies have shown that exposure to However, the impact of low LET (< 1 keV/μm) protons, which significantly contribute to the total radiation flux astronauts encounter within spacecraft, on ATSET performance is unknown. To address this gap, we evaluated the effects of cranial irradiation with 10 cGy of 100 MeV/n protons (LET = 0.732 keV/μm) on ATSET performance in male Sprague-Dawley rats. We also investigated whether concurrent exposure to variable gravity (hypergravity step-up, step down, purported to have the same effect as exposure to microgravity (another major spaceflight stressor) exacerbated SR-induced cognitive deficits. Our findings indicate that proton exposure alone significantly impaired ATSET performance, as evidenced by decreased processing speed while performing compound discrimination reversal and extra-dimensional shifting. Notably, no additive or synergistic effects were observed when hypergravity was combined with proton exposure. The impact that low-dose proton exposure has on CNS functionality, particularly in reducing processing speed during complex tasks, warrant further investigation. If similar cognitive deficits were to occur in astronauts exposed to galactic cosmic rays, mission success and safety could be significantly compromised.

Fusion-Based Utilization And Synthesis Of Efficient Detections, Ethan C. Rogers, Parker H. Liberatore, Thomas G. James

Endeavors: Mississippi State Undergraduate Research Journal

This study aimed to develop hardware and software for an object detection fusion system, using three different sensors. The system was built and studied with the motivating application of autonomous drones searching for and detecting people in a search-and-rescue scenario. The system’s performance was compared to that of individual sensors deployed for the same task. The focus of the research was to prove the competence and benefits of a decision-level fusion method as it was applied to a lightweight object detection architecture, and the driving motivators behind the study were simplicity in implementation and good computational performance. In short, the …

Design Strategy For Hybrid Thrust Air Bearings: Comparative Analysis Of Rigid Vs. Foil Bearings Considering Optimum Taper Angle And Orifice Location With Experimental Validation, Ehiremen Ebewele

Mechanical and Aerospace Engineering Dissertations - Archive

Gas foil thrust bearings (GFTBs) are contactless bearings that offer advantages such as lightweight construction and the ability to accommodate misalignments and geometric irregularities. However, their load capacity is lower than rigid or magnetic bearings. The structure and geometry of the foil significantly influence GFTB performance. The taper-flat design is the most used configuration due to its effectiveness and ease of implementation. Key parameters in designing this geometry include taper ratio, taper height, orifice size, and orifice location. These parameters must be optimized alongside manufacturing constraints to produce an effective GFTB. This study presents a design optimization investigation of various …

Computational Study Of Detonation Wave Propagation And Propellant Injection In Detonation Engines, Jayson C. Small

Mechanical and Aerospace Engineering Dissertations - Archive

This research investigates the physics of detonation waves and their application to detonation engines, with two primary objectives: (1) to characterize detonation wave propagation, specifically detonation speed and wavefront thickness, in stoichiometric propane-oxygen mixtures near quenching conditions, and (2) to examine the physiochemical processes during propellant injection under detonation engine conditions, focusing on flush-wall-mounted, fluidic-valve injectors.

A multi-fidelity computational approach was employed. Reduced-order modeling based on the Chapman–Jouguet and Zeldovich–von Neumann–Doring models were used to evaluate detonation parameters and select an appropriate chemical mechanism. High-fidelity, multi-dimensional simulations solved the unsteady, compressible, reacting flows with finite-rate chemistry, using Reynolds-Averaged Navier–Stokes equations …

Topology-Driven Performance Analyses In Consensus Algorithms For Multi-Agent Systems, Brandon Ayala

Mechanical and Aerospace Engineering Theses - Archive

This thesis presents a simulation-based analysis of consensus algorithms in multi-agent systems, focusing on how network topology influences convergence performance. Both first-order and second-order linear consensus dynamics were examined across a variety of network configurations, including undirected and directed versions of cycle graphs, star graphs, minimum spanning trees, and fully connected graphs. In addition to standard consensus problems, leader-follower network structures were introduced to explore the impact of leader placement on convergence behavior, and extensions to multi-leader systems were analyzed to study robustness and convergence under multiple reference inputs. Graph-theoretic properties such as connectivity, degree distribution, and Laplacian eigenvalues were …

Multi-Agent Differential Games Under An Altruistic Equilibrium, Craig Alan Lovell

Mechanical and Aerospace Engineering Theses - Archive

This work studies a multi-agent differential game with linear dynamics under the Berge equilibrium. The governing coupled differential equations for a two-agent and a three-agent game under the Berge equilibrium are derived. These games are simulated and compared to the Nash equilibrium. A sensitivity study is performed which validates that, under some criteria, the Nash equilibrium can be recovered from the Berge equilibrium. Policy fusion between the Berge and Nash equilibrium is explored in a two-agent game. A five-agent game under the Berge equilibrium is simulated and multiple teams of agents in this game are evaluated. Finally, a mixed game, …

Graphene-Polymer Nanocomposite For Electromagnetic Interference Shielding, Ravi Venkata Surya Sai Mogilisetti

Mechanical and Aerospace Engineering Theses - Archive

Polymers have widespread usage in most industries, such as aerospace, automotive, telecommunications, and medicine, mainly because they have a positive lightweight nature and excellent mechanical properties. One significant advantage of polymeric materials is their ability to combine nano-fillers, greatly enhancing their mechanical, electrical, and thermal properties. In the category of polymer matrices, polypropylene (PP) is notable for its low cost, ease of processing, and balanced mechanical properties. However, its relatively lower modulus and strength limit their applications in high-performance engineering. This research explores the addition of graphene into polypropylene to improve its mechanical properties and establish a conductive network for …

A Time-Domain Boundary Integral Equation For Moving Acoustic Sources In Uniform Flow And Its Solution By An Advanced Time Propagation Approach, Fang Q. Hu, Douglas M. Nark

Mathematics & Statistics Faculty Publications

This paper presents a time-domain boundary integral equation (TDBIE) formulation for predicting acoustic scattering from moving sources in a uniform mean flow. This work is motivated by the increasing need for accurate aeroacoustic modeling of modern aircraft configurations, including VTOL and eVTOL systems with rotating components. A key challenge in time-domain scattering simulations with moving sources is the determination of retarded time for a given observer time, which involves solving an implicit equation at each time step. This can be computationally costly, particularly for numerical solution of the TDBIE where every surface element on the scattering body acts as an …

Cryogenic Gas Cell For Infrared Space Instrumentation, Trent Newswander, Scott Bailey, Mark Hervig, Phillip Scott, Ryan Luder, Mike Watson, Mike Oksness, Cody Secrist, Zack Hatfield

Space Dynamics Laboratory Publications

• NASA’s Dynamical Neutral Atmosphere-Ionosphere Coupling (DYNAMIC) mission aims to characterize the energy transfer between the ionosphere, thermosphere, and mesosphere

– Identified as a high priority solar terrestrial probe mission in two decadal surveys

– Led by Virginia Polytechnic Institute and State University

• The Doppler Wind and Temperature Sounder (DWTS) is being developed for flight on the DYNAMIC satellite

– Will provide the first comprehensive global dataset of winds and temperature in the mesosphere and thermosphere (40–250 km altitude)

– Designed and built by Space Dynamics Lab (SDL)

• DWTS observes the Doppler shift of atmospheric NO and ^{13 …}

Design And Characterization Of The Icon Fuv Ccd Cameras, Erik Syrstad, Brian Thompson, Robert Burt, Mitch Whiteley, James Champagne, Pedro Sevilla

Space Dynamics Laboratory Publications

Outline

• FUV Overview
• Key Requirements
• Camera Design
• Assembly and Integration
• UV Performance Characterization

Atms And Cris Geolocation, Mark Esplin, Kris Robinson, Ben Esplin, Nephi Grant, Deron Scott, Likun Wang

Space Dynamics Laboratory Publications

Contents

• Summary of Suomi NPP sensors CrIS, ATMS, and VIIRS 
• Geolocation methods 
• Software optimization
• CrIS geolocation results
• ATMS geolocation results
• Conclusions

Comparison Of Co-Located Mid-Latitude Sporadic E And Simone Wind Observations, Ivana Molina, Kenneth Obenberger, Jorge Chau, Matthias Clahsen

Space Dynamics Laboratory Publications

Sporadic E are localized layers of enhanced metallic ionization that form in the E region of the ionosphere (Mathews, 1998). They are usually observed between 95 and 120 km altitude with a thickness in altitude ranging from ~100 m to a few kilometers. Studying these layers is important, as their characteristics and variability impact the propagation of HF radio waves. At mid-latitudes, the generation of sporadic E is most often explained by the wind shear theory, where these layers form due to the convergence of ions generated by vertical shears in the horizontal components of the neutral wind. The primary …

Passive Thermal Control Technologies: Short Course, Holly Mortensen, Matt Ralphs

Space Dynamics Laboratory Publications

• Introduction to Space Dynamics Laboratory
• Overview - Thermal Control Technologies
• Conductor Bars
• Thermal Straps
• Break
• Radiators
• Thermal Switches

Phase Change Cells, T. Shane Topham, Gail Bingham, Harry Latvakoski, Mike Watson

Space Dynamics Laboratory Publications

Outline

• Phase Change Cell Introduction
• Summary of ISS Phase Change Cell Experiments
• Ground Cell Design Improvements and Test Results

Space Dynamics Laboratory, Brent Carlsen, Doug Jewell

Space Dynamics Laboratory Publications

• Space Dynamics Laboratory
• SDL is a UARC
• RE-SET (Re-Engineering, System Engineering & Test)
• System Test Development

Development Of A Design Tool For Tow-Steered Composite Structures With Machine Learning-Assisted Modeling, Bangde Liu

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Fiber-reinforced composites (FRCs) are widely used in aerospace, automotive, and other engineering applications due to their lightweight characteristics and superior mechanical properties. Traditional FRCs employ a fixed fiber orientation in each layer, and while different layup sequences can tailor performance, the mechanical properties remain spatially uniform. Tow-steered composites, which enable fibers to follow curvilinear paths, offer the potential for spatially varying stiffness and strength, improving structural performance.

This dissertation addresses key challenges in modeling and designing tow-steered composite structures, including the lack of commercial design tools, the high computational cost of design optimization, and the need to efficiently evaluate manufacturing …

Deriving Nonlinearity Coefficients From Changing Background, Mark Esplin, Deron Scott, Bryce Walker, Ben Esplin

Space Dynamics Laboratory Publications

Contents

• Quadric Nonlinearity
• Nonlinearity Model and Sensitivity Studies
• Application to CrIS Sensor
• Check Method with Stepped Blackbody Data
• Conclusions

Guidelines For Radiometric Calibration Of Electro-Optical Instruments For Remote Sensing, Utah State University Space Dynamics Laboratory

Space Dynamics Laboratory Publications

SDL Presentation on Radiometric Calibration of Electro-Optical Instruments for Remote Sensing

Aircraft Turnaround Bottlenecks: Addressing Ground Handling Delays For Operational Excellence, Vigneswaran Cm, Syedeen Khan, Benedict M, Srinath R, Mukesh Pr, Jayaram R Pothnis, Inamul Hasan

International Journal of Aviation, Aeronautics, and Aerospace

Ground handling delays at major airports pose significant challenges, impacting operational efficiency, airline schedules, and passenger satisfaction. This study explores the root causes of these delays, including resource constraints, operational inefficiencies, adverse weather, technical failures, and security issues. By examining case studies from major airports, the report identifies key solutions such as technology integration, infrastructure upgrades, staff training, standardized procedures, and enhanced communication systems. The findings underscore the importance of adopting proactive and collaborative approaches to optimize ground handling operations, ensuring smoother airport workflows and improved service delivery in the face of growing air traffic demands.