Aerospace Engineering Commons^™

A Closer Look At Shielding Gas In Laser Powder Bed Fusion: A Review, Tasrif Ul Anwar, Nadia Kouraytem

Mechanical and Aerospace Engineering Student Publications and Presentations

The ongoing advancement of additive manufacturing (AM) techniques, particularly in laser powder bed fusion (LPBF), is effectively bridging the knowledge gap between AM and conventional manufacturing methods. At present, most of the research is focused on optimizing key process parameters such as laser power, laser speed, hatch spacing, layer thickness, scan pattern, powder size distribution, and so on. These studies help improve the part density and refine the microstructure of LPBF components, thereby enhancing the mechanical properties. Despite these advancements, an area in LPBF that is receiving comparatively less attention is the shielding gas: its flow during the printing process, …

Atmospheric Waves Experiment (Awe) Thermal Control System: Review Of On-Orbit Performance, Matthew I. Ralphs, Mike Holt

Space Dynamics Laboratory Publications

This paper reviews the Atmospheric Waves Experiment (AWE) detector thermal control system’s (TCS) performance for over two years of operation on the Internation Space Station (ISS). The TCS employs active thermal control for the InGaAs detectors with thermoelectric coolers (TEC). Each of the four detectors are controlled by a dedicated TEC at a nominal setpoint of -30°C, with heat transported away via low-mass, high-conductance pyrolytic graphite sheet (PGS) thermal straps into a nickel-plated copper conductor bar. A bi-directional radiator with Silver Teflon ensures an unobstructed view that can radiate the heat away to space. Titanium isolators decouple the detectors from …

A Suite Of Thermal Switches For Surviving Extreme Thermal Environments In Space, Matthew I. Ralphs, Matt Jensen, Alexis Eames, Matt Sinfield

Space Dynamics Laboratory Publications

Thermal switches are a key enabling technology for spacecraft operating in extreme thermal environments. Whether surviving the lunar night, managing intermittent high-power loads from deep space communication systems, or dealing with other extreme thermal environments, high-performance thermal switches allow critical missions to operate beyond conventional thermal design limits. This paper presents the development, testing, and performance of a suite of passive thermal switches designed for both spacecraft- and subsystem-level thermal control. The suite includes: (1) traditional in-line switch placed between sensitive components and radiators; (2) compact designs suitable for integration into standard bolted joint interfaces to modulate the conductance between …

Hypersonic Non-Equilibrium Cfd And Dsmc Model Comparisons With The Varda Reentry Capsule, Jack D. Crespo, Paolo Valentini, Ashwin P. Rao, Zach S. Davis

Space Dynamics Laboratory Publications

Nonequilibrium aerothermodynamic modeling of the Varda hypersonic testbed capsule is conducted with direct simulation Monte Carlo (DSMC) and computational fluid dynamics (CFD) solvers. Flowfield properties at the 78 km reentry trajectory point are extracted to compute line of sight spectral radiance using two radiative emission codes, namely HARA and NEQAIR. Computed spectra are compared to spectral radiance measured by an in situ optical emission spectroscopy payload flown on Varda’s W-2 capsule in 2025. Model comparisons to the experimental data reveal discrepancies between the HARA and NEQAIR radiative emission predictions in both overall magnitude and qualitative behavior. NEQAIR was found to …

An Investigation Of A Mach 15 Flow Over A Blunt Wedge Using First-Principles Potential Energy Surfaces: Influence Of Wall Temperature, Paolo Valentini, Zach Davis, Maninder S. Grover, Nicholas J. Bisek

Space Dynamics Laboratory Publications

The simulation of a Mach 15 air flow over a blunt wedge is conducted using the direct molecular simulation (DMS) method. Due to partial dissociation of the air mixture at the imposed free stream conditions, the shock layer contains N₂, O₂, NO, N, and O. All potential energy surfaces (PESs) used to model the various molecular interactions only describe electronic ground states energetics. Thus, no electronic excitation is modeled. An isothermal wall boundary condition is imposed, with full momentum and energy accommodation. Two wall temperatures are considered in this work, namely 1,000 K and 2,000 K. …

Beyond The Honeypot: Increasing Adversarial Cognitive Load Through Interactionless Cyber Deception, Marcus Rozier, Connor Dedic, Ted Mcdaniel, Hadley Westover

Space Dynamics Laboratory Publications

Traditional cyber deception mechanisms, such as honeypots and honey-tokens, typically rely on adversary interaction to trigger alerts and provide defensive value. This paper introduces the concept of interactionless deception—a defensive paradigm focused on the strategic manipulation of the environment to disrupt the cyber kill chain without requiring direct engagement. By utilizing a greedy top-k selection method to analyze MITRE ATT&CK® data across 178 Advanced Persistent Threat (APT) groups, this research identifies seven high-frequency sub-techniques that represent common attacker behavior. To counter these, the authors developed a series of proof-of-concept tools, including deceptive web proxies, simulated command-and-control (C2) beacons, and …

A Low Noise, High Qe, Large Format Ccd Camera System For The Nasa Mighti Instrument, Jed Hancock, Joel Cardon, Mike Watson, James Cook, Mitch Whiteley, James Beukers, Chris Englert, Charlie Brown, John Harlander

Space Dynamics Laboratory Publications

Outline

• MIGHTI Instrument Overview and Configuration
• Camera System Block Diagram
• Flight Camera Heads, Electronics Box, and CCDs
• CCD Testing at e2v
• AI&T at the Space Dynamics Lab
• Electro-Optical Characterization and Performance Results
• Conclusions

Geolocation Algorithms And On-Orbit Calibration For Atmospheric Waves Experiment, Eric Mckinney, Keith Blonquist, Zack Hatfield, Connor Waite, Brooke Wursten, Pedro Sevilla, Ludger Scherliess, Harri Latvakoski, Greg Cantwell

Space Dynamics Laboratory Publications

1 - Overview

• Motivation: Atmospheric gravity waves can degrade navigation, tracking, communications, and geolocation system signals. They can also affect satellite/debris orbit and reentry predictions.
• NASA's Atmospheric Waves Experiment (AWE) is currently on ISS measuring atmospheric gravity waves in the OH airglow layer at ~87 km altitude
• Impact: Improved space weather understanding, estimation, and forecasting

Return Of Ospree: In Situ Spectroscopic Measurements During Atmospheric Reentry, Ashwin P. Rao, Jack D. Crespo, Paolo Valentini, Vanessa J. Murray, Erin I. Vaughan, Zach Davis, Robert Alviani, Marat Kulakhmetov

Space Dynamics Laboratory Publications

Optical emission spectroscopy (OES) measurements of the reentry shock layer can provide invaluable information about the dynamic aerothermal chemistry during atmospheric reentry and yield critical data needed to improve fluid dynamics modeling of reentry systems. On 28 February 2025, the Air Force Research Laboratory successfully executed the Optical Sensing of Plasmas in the ReEntry Environment (OSPREE) experiment using Varda Space Industries’ W-2 hypersonic test-bed vehicle, obtaining in situ shock-layer radiative emission measurements during reentry from an altitude of 105 km down through 50 km, encompassing a range of Mach numbers between 29.5 and 15.0. We present a summary of the …

Mesopause-Region Gravity Wave Activity Due To Tropical Convection As Observed By Awe, Jeffrey M. Forbes, Xiaoli Zhang, Jiarong Zhang, Stephen D. Eckermann, Yucheng Zhao, Pierre-Dominique Pautet, Jun Ma, Ludger Scherliess, Michael J. Taylor

Space Dynamics Laboratory Publications

Mesopause-region (∼ 87 km) gravity waves (GWs) generated by tropical convection are investigated within the four longitude sectors encompassing Africa, the Indian Ocean, the Intertropical Convergence Zone, and South America during the Dec 2023– Feb 2024 Southern Hemisphere monsoon season. Variances (Q_v) in the OH Q-line emission measured by the Atmospheric Waves Experiment (AWE) capture GW activity, and precipitation rates (PR) from the Global Precipitation Measurement (GPM) Mission identify regions of convective activity. The zonal component of GWs comprising the Q_v between 10°S-10°N primarily propagate eastward. The Q_v distributions are latitudinally-shifted and more confined in …

Awe Amtm Geolocation Algorithms, Eric Mckinney, Keith Blonquist, Zack Hatfield, Connor Waite, Pedro Sevilla, Ludger Scherliess, Harri Latvakoski, Greg Cantwell

Space Dynamics Laboratory Publications

Mission Introduction

The AWE instrument images atmospheric gravity waves from the ISS, quantifying energy and momentum fluxes into the ionosphere-thermosphere system to better understand how tropospheric weather influences space weather.

Mission of Opportunity for the NASA Science Mission Directorate, Heliophysics Division.

Systems Intelligence Manager: Warfighter Dominance 2025 Technical Review Key Program, Daniel Hornberger

Space Dynamics Laboratory Publications

Objective & Background

• Objective
• Provide a governing network framework that reduces network congestion and improves connectivity, stability, and resilience
• Provide a single point for systems to connect to on varied networks, which also federates data to required entities
• Manage complex military CONOPs, controlling one or many heterogeneous unmanned platforms while coordinating collection efforts of varying sensor suites on each platform

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

The Doppler Wind and Temperature Sounder (DWTS) is being developed for flight on NASA’s Dynamical Neutral Atmosphere-Ionosphere Coupling (DYNAMIC) satellite. DWTS will view the Earth limb orthogonal to the spacecraft ram and uses gas-filter correlation radiometry to detect the Doppler shift of atmospheric emission. The observations yield horizontal winds and kinetic temperature with high precision, excellent spatial resolution, and altitude coverage from 40–250 km. DWTS detects Doppler shifting of NO and 13CO2 atmospheric emission lines by passing the incident light through an onboard cell containing both gases that is cooled to near cryogenic temperatures. This work describes the DWTS instrument, …

Nitric Oxide Radiometer Development, Deron Scott, Phil Scott, Trent Newswander, Marty Mlynczak

Space Dynamics Laboratory Publications

SDL developed a small satellite payload to support the NICEcube mission concept capable of measuring vertical profiles of infrared radiance at 5.3 µm from nitric oxide (NO) in the atmospheric limb (100-250 km). These radiance measurements can be directly inverted to achieve vertical profiles of infrared cooling rates which are crucial to understanding the density response to the thermosphere in times of elevated geomagnetic activity. The payload was designed to fit on a 12U cube sat, function at low power and small mechanical envelope. Completed work includes building the telescope, integrating a representative detector, alignment, test planning, and initial testing. …

The Atmospheric Waves Experiment (Awe), L. Scherliess, M. J. Taylor, P.-Dominique Pautet, Y. Zhao, B. Lamborn, H. Latvakoski, G. Cantwell, P. Sevilla, E. Syrstad, J. Forbes, S. Eckermann, D. Fritts, D. Janches, H. Liu, J. Snively

Space Dynamics Laboratory Publications

Modern theory and modeling indicate that atmospheric gravity waves (AGWs) play an important role in vertical coupling of the atmosphere-ionosphere system. Although small-scale AGWs (horizontal wavelengths ~30–300 km) are thought to account for the dominant energy and momentum inputs at Ionosphere-Thermosphere-Mesosphere (ITM) altitudes, the sources, variability, and influences of small-scale AGWs are still major unknowns. NASA’s Atmospheric Waves Experiment (AWE) mission is a Heliophysics Small Explorers Mission of Opportunity designed to investigate how terrestrial weather affects space weather, via small-scale AGWs produced in Earth’s atmosphere. Installed on the International Space Station (ISS) in November 2023, AWE began its 2-year mission …

Distributed Coherent Beamforming At 60 Ghz Enabled By Optically-Established Coherence, Drake Silbernagel, Yu Rong, Isabella Lenz, Prithvi Hemanth, Carl Morgenstern, Owen Ma, Nolan Matthews, Nadar Zaki, Kyle W. Martin, John D. Elgin, Jacob Holtom, Daniel W. Bliss, Kimberly Frey

Space Dynamics Laboratory Publications

We implement and experimentally demonstrate a 60 GHz distributed system leveraging an optical time synchronization system that provides precise time and frequency alignment between independent elements of the distributed mesh. Utilizing such accurate coherence, we perform receive beamforming with interference rejection and transmit nulling. In these configurations, the system achieves a coherent gain over an incoherent network of N nodes, significantly improving the relevant signal power ratios. Our system demonstrates extended array phase coherence times, enabling advanced techniques. Results from over-the-air experiments demonstrate a 14.3 dB signal-to-interference-plus-noise improvement in interference-laden scenarios with a contributing 13.5 dB null towards interference in …

Orographic Wave Activity At Mesospheric Altitude Over The Southern Ocean Islands Observed By The Atmospheric Waves Experiment, P.-D. Pautet, S. D. Eckermann, L. Scherliess, J. Ma, Y. Zhao

Space Dynamics Laboratory Publications

A major source for the gravity waves (GW) measured in the stratosphere and higher is the orographic forcing produced by the tropospheric wind blowing over mountainous regions. Recent studies have shown that even small islands can generate waves which, under appropriate conditions, are able to penetrate above 80 km altitude, transporting large amount of momentum into the upper atmosphere. Investigating the exact effects of those islands is challenging because ground-based and even airborne measurements are limited above those generally isolated places.

The Utah State University (USU) Atmospheric Waves Experiment (AWE) was designed and built to study mesospheric GW globally, even …

Mesospheric Gravity Waves Observed By Nasa Atmospheric Waves Experiment (Awe), Yucheng Zhao, Jiarong Zhang, Pierre-Dominique Pautet, Jun Ma, Joe Mcinerney, Hanli Liu, Steve Eckermann, Ludger Scherliess, Michael John Taylor, Burt Lamborn, Russ Kirkham

Space Dynamics Laboratory Publications

Although smaller scale gravity waves (GWs) (horizontal wavelengths ~30–300 km) are thought to account for the dominant energy and momentum inputs at the Ionosphere-Thermosphere-Mesosphere (ITM) altitudes, the sources, variability, and influences of these smaller-scale GWs are still major unknowns. The NASA Atmospheric Waves Experiment (AWE) is designed to measure these GWs in the mesopause region. In November 2023, AWE was successfully launched and deployed on the International Space Station (ISS) and science data collection was started. The AWE instrument maps the nighttime hydroxyl (OH) layer (~87 km), providing 2D GW fields in mesospheric temperature and OH band intensity over a …

Lifting-Line Predictions For Optimal Dihedral Distributions In Ground Effect, Amanda K. Olsen, Zachary S. Montgomery, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

When a flying wing comes within close proximity to the ground, a phenomenon called ground effect occurs where the lift is increased and the induced drag is decreased. This research seeks to determine the optimal dihedral distribution predicted by lifting-line theory that minimizes induced drag in ground effect. Despite some limitations, using lifting-line theory for this study allows for quick results across a large range of design variables, which would be infeasible for high-fidelity methods. The SLSQP optimization method is used along with a numerical lifting-line code to find the dihedral distribution that minimizes induced drag. Results are presented showing …

Grain Size- And Temperature-Dependent Phonon-Mediated Heat Transport In The Solid Electrolyte Interphase: A First-Principles Study, Arjun S. Kulathuvayal, Yanqing Su

Mechanical and Aerospace Engineering Student Publications and Presentations

The solid electrolyte interphase (SEI) is a passive layer, typically a few hundred angstroms thick, that forms on the electrode surface in the first few battery cycles when the electrode is in contact with the electrolyte in lithium-metal batteries. Composed of a combination of lithium salts and organic compounds, the SEI plays a critical role in battery performance, serving as a channel for Li-ion shuttling. Its structure typically comprises an inorganic component-rich sublayer near the electrode and an outer organic component-rich sublayer. Understanding heat transport through the SEI is crucial for improving battery pack safety, particularly since the Li-ion diffusion …

Satellite Passive Ranging Metasurface Optics For Space Rendezvous And Proximity Operations, Zachary Coppens, Cameron Vo, Addison Long, Jeremy Harris

Space Dynamics Laboratory Publications

SDL Presentation on Satellite Passive Ranging Metasurface Optics for Space Rendezvous and Proximity Operations

An Inexpensive, Open, And Extensible Hardware-In-The-Loop Cubesat Test And Simulation Infrastructure, Andrew Greenberg, Glenn Lebrasseur, Max Eltzroth, Rose Edington, Anna Meneely, Maxwell Millar

Small Satellite Conference

We have developed an inexpensive, open source, and extensible hardware-in-the-loop (HIL) test and simulation system to allow even small CubeSat teams to dramatically improve their testing infrastructure to increase reliability during flight.

Opto-Mechanical Properties Of Monocrystalline Germanium, Phil Scott, Lennon Reinhart, Patrick Strong, Ryan Luder, Shayler Backlund, Trent Newswander

Space Dynamics Laboratory Publications

SDL Presentation on Opto-Mechanical Properties of Monocrystalline Germanium

Atmospheric Waves Experiment (Awe) Thermal Balance: Internal Characterization, Correlation, And Lessons Learned, Matt Ralphs, Mike Holt

Space Dynamics Laboratory Publications

The Atmospheric Waves Experiment (AWE) is providing the first global characterization of atmospheric waves that originate in Earth’s lower atmosphere and affect space weather. The instrument has been installed on the International Space Station’s (ISS) ExPRESS Logistics Carrier (ELC) site 1 since November 2023. The AWE flight thermal balance test at Space Dynamics Laboratory (SDL) was unique in that the radiation exchange from the radiators was not tested prior to flight. Instead, heaters were placed on the radiators to simulate environmental heat and control the boundary temperatures. Multi-layer insulation (MLI) was installed over the radiators and heat flow meters were …

Development And Application Of Novel Apparatus For Ocean Spray In Turbulent Atmospheres, Alicyn S. Koldewyn

All Graduate Reports and Creative Projects, Fall 2023 to Present

Ocean spray droplets can have significant effects including reducing surface heating from the sun, degrading air quality, and intensifying tropical cyclones. However, quantifying these effects has been challenging due to the multiscale, chaotic nature of wave breaking and turbulent flow. This research presents the development of a novel apparatus designed to combine bubble column droplet generation with synthetic jet actuators for turbulence generation. The purpose is to demonstrate reliable bubble formation and droplet generation, air turbulence effect on droplet dynamics, and quantitative measurement and analysis of these effects. The primary goals of the apparatus include optical accessibility for high-resolution imaging, …

Linearized Rigid-Body Dynamics Of Asymmetric Aircraft, Troy A. Abraham

All Graduate Theses and Dissertations, Fall 2023 to Present

Most aircraft are symmetric about their mid-plane, which permits simplifying assumptions when modeling their aerodynamic and mass properties, as well as estimating their dynamic modes. This work considers methods for modeling asymmetric aircraft, including capturing the dynamic mode characteristics that result from their asymmetric properties. While the primary focus of this work is on the dynamic mode properties of these aircraft, a significant portion of the dissertation is dedicated to modeling their aerodynamic, mass, and trimmed flight characteristics. The linearized rigid-body aircraft equations of motion used for dynamic mode estimates are developed to include the effects of asymmetries in both …

Evaluating The Impact Of Maximum Aero-Thermal Heating On A High-Speed Fixed-Wing Atmospheric Aircraft Optimum Trajectory, Benjamin M. Ford

All Graduate Theses and Dissertations, Fall 2023 to Present

This study explores how extreme heating affects the flight paths of hypersonic aircraft—vehicles that travel at speeds many times faster than sound. Analyzing how to fly a high-speed aircraft without overheating it can prevent structural failure while operating at maximum possible performance. The results shown in this section indicate that it is possible to operate at very high speeds in an aircraft while keeping peak vehicle temperature below our limits while saving fuel.

Deployable Systems Eat, Utah State University Space Dynamics Laboratory

Space Dynamics Laboratory Publications

What Are Mechanisms?

• Moving Mechanical Assembly (MMA)

• A device that controls the movement of a deployable or other movable system of a space or launch vehicle

• Why do mechanisms exist?

• 1) Fit within launch vehicle or dispenser
• 2) Stow for launch loads
• 3) Change position or pointing once on orbit
• 4) Deploy objects

Thermal Design Overview, Utah State University Space Dynamics Laboratory

Space Dynamics Laboratory Publications

Preface

• Introductions
• Work Based on "Small Satellite Thermal Modeling Guide, Initial Release, July 2022"
• Air Force Research Laboratory Space Vehicles Directorate (AFRL/RVSV)
• Purpose
• Introduce methods/concepts to develop and analyze a small satellite thermal model
• Understand why thermal modeling and thermal analysis are important
• Understand common pitfalls
• Learn about available resources

Global Variation Of Mesospheric Gravity Waves Observed By Awe, Yucheng Zhao, Jiarong Zhang, Pierre-Dominique Pautet, Ludger Scherliess, Michael J. Taylor

Space Dynamics Laboratory Publications

USU Presentation on the Global Variation of Mesospheric Gravity Waves Observed by AWE