Digital Commons Network^™

Novel Load Bearing Antennas For Cubesat Applications, Manohar Deshpande

Small Satellite Conference

Increasingly, CubeSat and Small Satellite platforms are used for space exploration and Earth science remote sensing from LEO locations. Due to their low cost and fast deployment time, CubeSat platforms are also employed for new technology development and technology readiness level (TRL) maturation in the space environment. RF antennas are essential components of these CubeSat/Small Satellite platforms used for communication and remote sensing radars/radiometers. Types of antennas currently used on CubeSat/Small Satellite platforms include; monopole/dipole antennas; printed antennas; printed antennas integrated with a solar cell; and antennas printed on the backside of solar cell. These types of antennas need a …

The Development Status Of The First Demonstration Satellite Of Our Commercial Small Synthetic Aperture Radar Satellite Constellation, Toshihiro Obata, Hirobumi Saito, Koji Tanaka, Shinichi Nakasuka, Seiko Shirasaka

Small Satellite Conference

Expectations for SAR (Synthetic Aperture Radar) satellites that can observe a target area through clouds and during nighttime are emerging, especially in Asia where high cloud cover rate prevent from the satellite monitoring with optical sensors. We are now developing a small SAR satellite based on technologies of ImPACT (Impulsing PAradigm Change through disruptive Technologies) program. This program aims to develop a responsive earth observation system with the small SAR satellite, originally target for disaster monitoring. We will build a constellation of the small SAR satellites to realize short term revisits, shorter than one day to take advantage of SAR …

Cheops: The Esa Mission For Exo-Planets Characterization Ready For Launch, Joel Asquier, Nicola Rando, Carlos Corral Van Damme, Francesco Ratti, K. Isaak, R. Southworth, F. Safa, C. Broeg, T. Beck, W. Benz, A. Borges, D. Cortes, R. Palacios

Small Satellite Conference

The European Space Agency (ESA) Science Programme Committee (SPC) selected CHEOPS (Characterizing Exoplanets Satellite) in October 2012 as the first Small-class mission (S1) within the Agency’s Scientific Programme. It is considered as a pilot case for implementing “small science missions” in the agency with the following requirements: science driven mission selected through an open Call; an implementation cycle, from the Call to launch, drastically shorter than for Medium-class (M) and Large-class (L) missions; a strict cost-cap to ESA, with possibly higher Member States involvement than for M or L missions.

The CHEOPS mission is devoted to the characterization of known …

A Formal Approach To Verification And Validation Of Guidance, Navigation, And Control Algorithms, Jason Crane, Jason Westphal, Islam Hussein, Meeko Oishi, Abraham Vinod, Joseph Gleason

Small Satellite Conference

The traditional Monte Carlo based approaches to Verification & Validation (V&V) of Guidance Navigation and Control (GN&C) algorithms suffers from drawbacks, including typically requiring a significant amount of computational resources to guarantee a candidate algorithm’s appropriateness. Formal approaches to V&V of GN&C algorithms can help address these is-sues as they are not based on simulation. Therefore, we are investigating and developing an innovative formal V&V algorithm for spacecraft GN&C, specifically in the determination of safety of maneuvers for satellite Remote Proximity Operations and Docking (RPOD). Formal V&V methods could provide rigorous and quantifiable assurances of safety for a given satellite …

Educative Platform Based On The Pocketqube 60 Standard, Ivan Ibrahim Fernandez-Morales, Sergio Escobedo-Juarez, Roxana Lechuga-Rodriquez, Israel Alejandro Arriaga-Trejo

Small Satellite Conference

We present the results of workshops aimed to high school students in the State of Zacatecas, Mexico using an educational platform based on the PocketQube60 electrical specification. The modules that constitute the platform (EPS, OBC, COMMS and the payload) were designed by engineering students of the Autonomous University of Zacatecas.

Guest Editorial Spacecraft Charging Technology, Allen Andersen, Michael Bodeau, Mengu Cho, Victoria A. Davis, Jr Dennison, Michelle Donegan, Dale C. Ferguson, Nelson Green, Virginie Inguimbert, Insoo Jun, Shu T. Lai, Justin J. Likar, Joseph Minow, Linda Neergaard Parker, Jean-François Roussel, Kazuhiro Toyoda, Henry B. Garrett, Hideyuki Usui

Journal Articles

This marks the seventh issue of the IEEE Transactions on Plasma Science dedicated to Spacecraft Charging Technology. The theme of this issue is based on the papers presented at the 15th Spacecraft Charging Technology Conference, Kobe, Japan, in 2018. The history of spacecraft charging goes back to the first Spacecraft Charging Technology Conference, sponsored by AFRL and NASA, that was held at the U.S. Air Force Academy, Colorado Springs, CO, USA, in 1978. The 15th Spacecraft Charging Technology Conference was hosted by the Japan Aerospace Exploration Agency (JAXA) and the Graduate School of System Informatics, Kobe University. It continues a …

Monitoring Ambient Laboratory Conditions With A Raspberry Pi, Joshua Boman

Physics Capstone Projects

Precise experimental devices and measurements can be sensitive to changing physical conditions in the lab. The purpose of this research was to develop a standardized computer automated package to monitor and record changes in laboratory conditions, including ambient temperature, atmospheric pressure, relative humidity, light intensity, motion, and power outages. The computer-interfaced device was based around an inexpensive Raspberry Pi microcomputer and commercially available sensors. The Raspberry Pi uploads the sensor data to a file used by LabVIEW to further analyze, plot and display the calibrated sensor data in real time and trigger alarms. This capability allows the Material Physics Research …

Vibronic Fingerprint Of Singlet Fission In Hexacene, Gang-Hua Deng, Qianshun Wei, Jian Han, Yuqin Qian, Jun Luo, Avetik R. Harutyunyan, Gugang Chen, Hongtao Bian, Hanning Chen, Yi Rao

Chemistry and Biochemistry Faculty Publications

Singlet fission has the great potential to overcome the Shockley–Queisser thermodynamic limit and thus promotes solar power conversion efficiency. However, the current limited understandings of detailed singlet fission mechanisms hinder a further improved design of versatile singlet fission materials. In the present study, we combined ultrafast transient infrared spectroscopy with ab initio calculations to elucidate the roles played by the vibrational normal modes in the process of singlet fission for hexacene. Our transient infrared experiments revealed three groups of vibrational modes that are prominent in vibronic coupling upon photoexcitation. Through our computational study, those normal modes with notable Franck-Condon shifts …

The Spectral Ocean Color Imager (Spoc) – An Adjustable Multispectral Imager, David L. Cotten, Nicholas Neel, Deepak Mishra, Marguerite Madden, Caleb Adams, Susanne Ullrich, Adrian Burd, Malcolm Adams, Kaitlyn Summey, Casper Versteeg, Jackson Parker, Fred Beyette

Small Satellite Conference

SPOC (SPectral Ocean Color) is a 3U small satellite mission that will use an adjustable multispectral imager to map sensitive coastal regions and off coast water quality of Georgia and beyond. SPOC is being developed by the University of Georgia’s (UGA) Small Satellite Research Laboratory (SSRL) through NASA’s Undergraduate Student Instrument Project (USIP). UGA is working with Cloudland Instruments to develop a small scale (< 1000 >cm3) multispectral imager, ranging from 400-850nm, for Earth science applications which will fly as part of the NASA CubeSat Launch Initiative.

The project is UGA’s first satellite mission and is built by a team of …

Aero & Vista: Demonstrating Hf Radio Interferometry With Vector Sensors, Frank D. Lind, Philip J. Erickson, Michael Hecht, Mary Knapp, Geoffrey Crew, Ryan Volz, John Swoboda, Frank Robey, Mark Silver, Alan J. Fenn, Benjamin Malphrus, Kerri Cahoy

Small Satellite Conference

AERO (Auroral Emission Radio Observer) and VISTA (Vector Interferometry Space Technology using AERO) are recently selected NASA HTIDeS CubeSat missions for terrestrial auroral science and radio interferometric technology demonstration. The AERO and VISTA CubeSats both host vector sensing antenna systems providing advanced electromagnetic capabilities. Together, they will provide the first in-space demonstration of interferometric imaging, beamforming, and nulling using electromagnetic vector sensors at low frequencies (100 kHz –15 MHz). A key goal of the joint missions’ technology demonstration is to validate theoretical sensor performance modeling indicating that interferometric arrays composed of vector sensors will be able to maintain sensitivity even …

Nasa Undergraduate Student Instrument Project (Usip) Lessons Learned, Joyce Winterton, Dave Pierce, Janet Letchworth, Brenda Dingwall

Small Satellite Conference

NASA offers real-world experiences, with the goal of developing students’ competencies in science, technology, engineering and math (STEM), skills critical to building a STEM-literate workforce and achieving the nation's exploration goals. In 2016, the NASA Science Mission Directorate (SMD) and the Office of Education National Space Grant Program (OE Space Grant) awarded $8 million through the Undergraduate Student Instrument Project (USIP) to 47 student teams to conduct hands-on research with 23 of the projects being CubeSat projects. The USIP student teams proposed science or technology experiments that are relevant to NASA missions, and the platform to fly their payload. The …

University Nanosatellite Program – 20 Years Of Education, Jesse Olson

Small Satellite Conference

In 1999, the Air Force Research Laboratory’s Space Vehicles Directorate (AFRL/RV) and Air Force Office of Scientific Research (AFOSR) began a unique program with the goal of educating future small satellite systems engineers – the University Nanosatellite Program (UNP). In the ensuing 20 years, 38 universities, and over 5,000 students, have participated in UNP, developing nearly 100 unique mission concepts and resulting in 11 flights to-date. Through UNP, full-time systems engineers are dedicated to guiding student teams through the development process, utilizing a small satellite specific user’s guide, systems engineering classes and presentations, formal reviews, access to government and industry …

Mission Dodona: Electronic Power System Design, Analysis And Integration, Sriram Narayanan, Rahul Rughani, Rebecca Rogers, Kyle Clarke, Jeremy Allam

Small Satellite Conference

“Dodona” is USC’s third CubeSat mission, and the electronic power system for this mission conforms to a centralized architecture common to the early-CubeSat class. The electronic power system is designed to power all satellite system components and any additional customer payload. A power budget is presented describing various operating configurations of the CubeSat and how its requirements are met in the design. The power system used a legacy Clyde Space 3U CubeSat Power System consisting of a combination of batteries and an Electronic Power System (EPS) to control charging, discharging, and voltage conversions for the system. The central architecture uses …

Cloud Cover And Delayed Herbivory Relative To Timing Of Spring Onset Interact To Dampen Climate Change Impacts On Net Ecosystem Exchange In A Coastal Alaskan Wetland, A. Joshua Leffler, Karen H. Beard, Katharine C. Kelsey, Ryan T. Choi, Joel A. Schmutz, Jeffrey M. Welker

Wildland Resources Faculty Publications

Rapid warming in northern ecosystems over the past four decades has resulted in earlier spring, increased precipitation, and altered timing of plant–animal interactions, such as herbivory. Advanced spring phenology can lead to longer growing seasons and increased carbon (C) uptake. Greater precipitation coincides with greater cloud cover possibly suppressing photosynthesis. Timing of herbivory relative to spring phenology influences plant biomass. None of these changes are mutually exclusive and their interactions could lead to unexpected consequences for Arctic ecosystem function. We examined the influence of advanced spring phenology, cloud cover, and timing of grazing on C exchange in the Yukon–Kuskokwim Delta …

Effects Of Halogen, Chalcogen, Pnicogen, And Tetrel Bonds On Ir And Nmr Spectra, Jia Lu, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Complexes were formed pairing FX, FHY, FH₂Z, and FH₃T (X = Cl, Br, I; Y = S, Se, Te; Z = P, As, Sb; T = Si, Ge, Sn) with NH₃ in order to form an A⋯N noncovalent bond, where A refers to the central atom. Geometries, energetics, atomic charges, and spectroscopic characteristics of these complexes were evaluated via DFT calculations. In all cases, the A–F bond, which is located opposite the base and is responsible for the σ-hole on the A atom, elongates and its stretching frequency undergoes a shift to the red. This …

Utah Women In Stem Education: A 2019 Update, Cheryl Hanewicz, Susan Thackeray, Susan R. Madsen

Marketing and Strategy Faculty Publications

According to a recent article in Utah Business Magazine, Utah had the strongest job growth in the nation in 2018, with no signs of slowing down. Forbes ranked Utah second in their 2018 Best States for Business scorecard, moving it up from third the previous year. Given the increase in the number of high-tech firms in Utah, it should come as no surprise that many jobs are based in the STEM (science, technology, engineering and mathematics) fields. In fact, Utah contains three of the top 100 best cities for STEM jobs in the United States, including Salt Lake City (#8), …

2019 Utah State University Orientation Guide, Utah State University

The Utah Statesman

A special supplemental magazine provided by The Utah Statesman to take a closer look at some of the services and departments available at Utah State University.

Secondary Electron Yield Measurements Of Carbon Nanotube Forests: Dependence On Morphology And Substrate, Brian Wood, Jordan Lee, Gregory Wilson, T. -C. Shen, Jr Dennison

Journal Articles

Total, secondary, and backscatter electron yield data were taken with beam energies between 15 eV and 30 keV, in conjunction with energy emission data, to determine the extent of suppression of yield caused by carbon nanotube (CNT) forest coatings on substrates. CNT forests can potentially lower substrate yield due to both its inherently low-yield, low-atomic number (Z) carbon composition, and its bundled, high-aspect ratio structure. Rough surfaces, and in particular, surfaces with deep high-aspect-ratio voids, can suppress yields, as the electrons emitted from lower lying surfaces are recaptured by surface protrusions rather than escaping the near-surface region. Yields of multilayered …

Optimal Vehicle Use In The Presence Of Episodic Mobile-Source Air Pollution, Arthur J. Caplan, Ramjee Acharya

Applied Economics Faculty Publications

This paper develops a conceptual model of vehicle trips in a region plagued by weather-dependent, mobile-source air pollution, and numerically estimates optimal trips for one of the nation's perennially worst air quality regions in terms of short-term particulate matter. Based upon data-driven parameters and damage estimates, our numerical model generates optimal values for region-wide vehicle trips and associated PM_2.5 concentrations along with their corresponding time paths. Our dataset includes a host of pertinent weather variables that determine PM_2.5 concentrations both independently as well as interacted with vehicle trips. As a result, our empirical model enables us to isolate …

Utah State Magazine, Fall 2019, Utah State University

Utah State Magazine

The quarterly magazine for friends and alumni of Utah State University.

Isentropic Efficiency And Theoretical Analysis Of The Planetary Rotor Expander, Joseph L. James

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Expanders allow pressurized fluids to undergo a pressure decrease in a controlled environment via volumetric growth to extract fluid energy. There are many types of expanders, and the objective of this thesis is to model the efficiencies of the planetary rotor expander (PRE), a century-old design undeveloped due to insufficient manufacturing capabilities (until recently). Geometric relationships are derived and mathematical models are generated to determine the efficiency of the PRE as a function of design variables. Two industrially relevant case studies show that, to maximize isentropic efficiency, the planetary rotor expander (PRE) rotational frequency is maximized and rotor geometry optimized.

Stamina: Stochastic Approximate Model-Checker For Infinite-State Analysis, Thakur Neupane

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Reliable operation of every day use computing system, from simple coffee machines to complex flight controller system in an aircraft, is necessary to save time, money, and in some cases lives. System testing can check for the presence of unwanted execution but cannot guarantee the absence of such. Probabilistic model checking techniques have demonstrated significant potential in verifying performance and reliability of various systems whose execution are defined with likelihood. However, its inability to scale limits its applicability in practice.

This thesis presents a new model checker, STAMINA, with efficient and scalable model truncation for probabilistic verification. STAMINA uses a …

Secondary Mathematics Teachers’ Responses To Pivotal Teaching Moments, Kami M. Dupree

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study used a multiple case study design to explore the occurrence of pivotal teaching moments, teachers’ responses to these moments, and teachers’ own perceptions of the impact of these moments on their own knowledge development. The participants were six practicing secondary mathematics teachers. The researcher collected data from teacher created lesson plan outlines, observations of the same lesson delivered to two different classes, participant interviews, and teacher reflection journals. The researcher reviewed the lesson plan outlines prior to observations to understand teachers’ anticipations. During observations, the researcher recorded observed pivotal teaching moments, corresponding teacher responses to these moments, and …

Tuning Hyperparameters In Supervised Learning Models And Applications Of Statistical Learning In Genome-Wide Association Studies With Emphasis On Heritability, Jill F. Lundell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Machine learning is a buzz word that has inundated popular culture in the last few years. This is a term for a computer method that can automatically learn and improve from data instead of being explicitly programmed at every step. Investigations regarding the best way to create and use these methods are prevalent in research. Machine learning models can be difficult to create because models need to be tuned. This dissertation explores the characteristics of tuning three popular machine learning models and finds a way to automatically select a set of tuning parameters. This information was used to create an …

The Political Business Cycle: Endogenous Election Timing & Hyperbolic Memory Discounting, Jake R. Cottle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the models analyzed in this paper, there exists an incumbent politician with one objective, two choices, and voters who remember the past differently. The politician's primary goal is to get reelected, which is done by maximizing the number of votes on the day of election. The politician can increase their chances of reelection if they influence the state of the economy over time and ensure the economy is in its 'best' state on the days leading up to the election.

In conducting this research, I wanted to study how different rates of memory decay influences the choices the politician …

The Influence Of Measurement Scale And Uncertainty On Interpretations Of River Migration, Mitchell R. Donovan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Environmental scientists increasingly use remotely-sensed images to measure how rivers develop over time and respond to upstream changes in environmental drivers such as land use, urbanization, deforestation and agricultural practices. These measurements are subject to uncertainty that can bias conclusions. The first step towards accurate interpretation of river channel change is properly quantifying and accounting for uncertainty involved in measuring changes in river morphology. In Chapter 2 we develop a comprehensive framework for quantifying uncertainty in measurements of river change derived from aerial images. The framework builds upon previous uncertainty research by describing best practices and context-specific strategies, comparing each …

Numerical Analysis And Spanwise Shape Optimization For Finite Wings Of Arbitrary Aspect Ratio, Joshua D. Hodson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work focuses on the development of efficient methods for wing shape optimization for morphing wing technologies. Existing wing shape optimization processes typically rely on computational fluid dynamics tools for aerodynamic analysis, but the computational cost of these tools makes optimization of all but the most basic problems intractable. In this work, we present a set of tools that can be used to efficiently explore the design spaces of morphing wings without reducing the fidelity of the results significantly. Specifically, this work discusses automatic differentiation of an aerodynamic analysis tool based on lifting line theory, a light-weight gradient-based optimization framework …

Constellation Planning Methods For Sequential Spacecraft Rendezvous Using Multi-Agent Scheduling, Skylar A. Cox, Nathan B. Stastny, Greg Droge, David K. Geller

Space Dynamics Laboratory Publications

This paper addresses the RPO constellation assignment problem by developing a responsive utility function for tasking a constellation of LEO satellites to several spacecraft servicing tasks. The paper develops the utility function that considers both value of servicing RSO spacecraft in conjunction with the associated ΔV cost. A highly-capable and operationally-relevant task allocation method, called the consensus-based bundle algorithm (CBBA), is leveraged for distributed processing and task allocation. This paper demonstrates that this methodology provides a robust technique for RPO constellation management.

Wireless Antenna Detection Of Electrostatic Discharge Events, Allen Andersen, Jr Dennison

Journal Articles

Wireless intraspacecraft communication technology is being developed for signal transfer on space missions to save weight and simplify the design. One consideration for this new technology is its interaction with space environmentinduced electrostatic discharges (ESDs). The short time scales of spacecraft ESD events result in broad frequency band signals that can interact with high-frequency wireless antennas. These interactions present a source of signal noise. However, they also present a possibility of in-flight wireless ESD monitoring. We present laboratory measurements of arcing on common spacecraft insulators using commercially available single-band 2.4-GHz and dual-band 2.4-/5.8-GHz Wi-Fi antennas. These wireless detections are shown …

A Novel Adaptive Lbp-Based Descriptor For Color Image Retrieval, Mohammad Sotoodeh, Mohammad Reza Moosavi, Reza Boostani

Computer Science Student Research

In this paper, we present two approaches to extract discriminative features for color image retrieval. The proposed local texture descriptors, based on Radial Mean Local Binary Pattern (RMLBP), are called Color RMCLBP (CRMCLBP) and Prototype Data Model (PDM). RMLBP is a robust to noise descriptor which has been proposed to extract texture features of gray scale images for texture classification.

For the first descriptor, the Radial Mean Completed Local Binary Pattern is applied to channels of the color space, independently. Then, the final descriptor is achieved by concatenating the histogram of the CRMCLBP_S/M/C component of each channel. Moreover, to enhance …