Digital Commons Network^™

Propellant-Free Formation Keeping Using Environmental Perturbations In Leo Via Orbital Angular Momentum Vector Matching, Yu Seike, Takaya Inamori, Keita Tanaka

Small Satellite Conference

Small-satellite formation flying enables new mission capabilities.

e.g. MIMO (Multi Input Multi Output) Communication

Challenge: Conventional formation keeping requires thrusters. Small satellites have limited onboard resources.

Johnathan Aaron Wayne Lacey

African American Funeral Programs

No abstract provided.

The Etsu Historian, Tyla Melkonyan

The ETSU Historian

No abstract provided.

Development And Validation Of An Operator-Friendly Flight Dynamics System For High-Precision Leo Nanosatellite Operations, K. W. Cheong, M. C. Kim, P. R. Kim, M. G. Kim, J. Y. Yu, G. H. Ju

Small Satellite Conference

A ground-based Flight Dynamics System (FDS) provides essential orbit information for satellite monitoring and mission planning. This study develops a Python-based integrated FDS that processes GPS observations, TLEs, and ephemerides through interconnected orbit determination, orbit propagation, and event prediction modules. The developed system combines Batch Least Squares orbit determination, HPOP/SGP4 propagation, covariance analysis, and nodal-crossing prediction within a consistent time and coordinate framework. 

The objective is to establish and validate an integrated workflow that generates reliable orbit states, future ephemerides, uncertainty information, and operational event products for CubeSat ground operations 

Multi-Phase Guidance And Control For Small Satellite Docking Via Deep Reinforcement Learning, Tanner Gill, Greg Furlich, Nisar Ahmed

Small Satellite Conference

As interest in small satellite Rendezvous, Proximity Operations, and Docking (RPOD) grows, so does the need for high-level autonomy in space systems. Current systems relying on constrained hardware and ground-in-the-loop decision-making are ill-equipped for the evolving, contested space domain. Recent research on autonomous spacecraft guidance and control has moved beyond established optimal control and trajectory optimization methods to incorporate Reinforcement Learning (RL), though these efforts have predominantly focused on a single operational phase. This research advances small satellite docking autonomy by formulating the reference scenario as a Hierarchical Markov Decision Process (H-MDP), expanding the scope of the learned guidance and …

The Ecological Impacts Of Un-Protecting Forests: The Case Of Gold Mining In Ghana, Tate Alexander Barend

Master's Theses

This paper estimates the causal effect of Ghana’s Legislative Instrument 2462 (L.I. 2462) on deforestation in protected areas. The policy redefined the regulatory regime governing small-scale gold mining in protected areas, moving from prohibition to discretionary permitting. I exploit the implementation of L.I. 2462 as a policy shock and apply a difference-in-differences event-study framework to a propensity score–matched sample of pixels derived from high-resolution satellite images. Contrary to widespread concerns that the policy would accelerate deforestation, the results provide no evidence of large-scale vegetation loss in exposed protected areas following the policy change. Instead, protected area pixels located within 5 …

Metal Oxide Semiconductor Gas Sensors For Exhaled Breath Cancer Biomarker Detection, Guanglan Chen, Huihui Luo, Wenwen Peng, Shiyu Xu, Yuting Li, Huijie Ke, Sihui Zhong, Jiaao Wei, Tong Chen, Xiaokun Li, Youlin Zhang, Wei Chen

Online First

Early cancer screening can significantly improve therapeutic outcomes, volatile organic compounds (VOCs) and other related gases in exhaled breath, as cancer-specific biomarkers, offer a novel approach for non-invasive diagnosis. Metal oxide semiconductor (MOS)-based gas sensors are pivotal for exhaled breath VOCs detection, featuring compact size, cost-effectiveness, and rapid response. This review summarizes the most recent five-year research advances in cancer biomarker detection and clarifies the core mechanisms of electrical property changes from sensing material-VOCs interactions and key performance metrics including sensitivity, selectivity, humidity tolerance, response/recovery time, stability, and operating temperature. This review highlights the optimization strategies of sensing materials such …

A Four-Year Analysis Of #Orthotwitter Use During Match Week: Can X Be A Potential Equalizer For Students Left Unmatched?, Desiree E Ojo, Davis Hedbany, Brook Willett, Brandon D Rust, Geoffrey Deckard, Omar Guerrero, Jalen Warren, Michael Megafu, Morgan Turnow, Jaime Bellamy

Medical Education Articles

Background The orthopedic surgery match has changed. Since the COVID-19 pandemic, orthopedic surgery candidates and residency programs have used #Orthotwitter to promote, advocate, and educate their followers. This study aimed to evaluate changes in the use of #OrthoTwitter and #OrthoMatch during Match Week over a four-year period, including trends in author type, post content, institutional affiliation, engagement, and posting activity, with particular attention to posts involving unmatched applicants. Methodology The top tweets containing the hashtags #Orthotwitter and/or #OrthoMatch during the 2021, 2022, 2023, and 2024 Match Week were reviewed and collected. Tweets between the years 2021, 2022, 2023, and 2024 …

Impact Of Sleep On Glucose Metabolism In Individuals With Overweight Or Obesity: A Systematic Review, Trudy Abla Sitsofe Accorley, Patricia Casas-Agustench, Gail Rees, Kathy Redfern

School of Biomedical Sciences

INTRODUCTION: The obesity epidemic has coincided with chronic sleep deprivation. Sleep disturbances may contribute to metabolic dysfunction in individuals with BMI ≥ 25 kg/m 2. This review investigates associations between sleep patterns and glucose metabolism in this population.

METHODS: A PRISMA-guided search across five databases (PubMed, Embase, Cochrane, CINAHL, and MEDLINE) was conducted through January 2026. Studies examined sleep patterns and glucose metabolism in adults with BMI ≥ 25 kg/m 2. Quality was assessed using the Cochrane Risk of Bias Tool 2.0 and Newcastle-Ottawa Scale.

RESULTS: Eighteen studies (7715 adults) were included from 2993 records: crossover trials (n = 7), …

Interpretable Multimodal Learning For Integrating Neuroimaging And Genetic Data In Alzheimer’S Disease, Kun Zhao, Siyuan Dai, Yingying Zhang, Guodong Liu, Pengfei Gu, Chenghua Lin, Paul M. Thompson, Alex D. Leow, Heng Huang, Haoteng Tang

Computer Science Faculty Publications

Introduction: Early detection of Alzheimer's disease (AD) requires models that combine brain structure changes with genetic risk, but existing methods struggle to align these different data types.

Methods: We present R-GenIMA, an interpretable multimodal large language model that pairs a region-of-interest vision transformer with genetic prompting to jointly analyze structural MRI and single nucleotide polymorphisms (SNPs). Each brain region becomes a visual token and SNP profiles are encoded as structured text, letting the model link regional atrophy to genetic factors through cross-modal attention. Tested on the ADNI cohort, R-GenIMA performs well in classifying four groups: normal cognition, subjective memory concerns, …

A Comparative Analysis Of Radio Frequency And Optical Inter-Satellite Link Communications For Leo Mega-Constellations, Alexa Houck, Suryansh Aryan, Kevin Schroeder, Samantha Kenyon

Small Satellite Conference

SpaceNet design  

Software-based testbed for simulating large satellite networks, specifically LEO-based constellations to analyze network behavior, connectivity, routing, and overall communication.  

• Phase one focuses on connectivity and routing: Given the topology and link availability over time, how does my network behave? 
• Phase two focuses on network emulation: Given the topology and link availability over time, how does my network behave? 

Austronauts 3u Cubesat Space Weather Payloads Proposal, Tiana Pendray

Small Satellite Conference

CubeSats are becoming increasingly prominent due to their accessibility, affordability and versatility. An emerging field of satellite application is the monitoring of ionospheric space weather, made possible by sensitive instruments that collect data on plasma potential, temperature and ion density. These parameters vary due to changing solar activity in the form of Coronal Mass Ejections (CMEs) and solar flares, which can have severe impacts on satellite navigation systems, radio communication networks and orbital estimations. The AUStronauts team at the University of New South Wales is developing a 3U CubeSat with two space weather payloads – an Electrodynamic Tether (EDT) and …

Autonomous Microelectronics See Payload For Validating Terrestrial Predictions In Space, Michael A. Blacconiere, Isaac Hudson, John W. Burgoon, Terrance Sacks, Spencer Westfall, Sajal Islam, Davidson Juhke, George Randel, Jared Harvey, Merek Chertkow, Daniel Loveless

Small Satellite Conference

The radiation environment in space is complex and time-varying, causing major risks for microelectronic applications. Terrestrial radiation sources are used to characterize devices before missions to predict in-orbit error rates. However, these predictions are rarely validated in deployment. The payload, designed by IU CREATE and The Radiation Team, the IUB-SAT-1, integrates IU’s RadFX-IC and commercial SRAMs with well-characterized terrestrial radiation responses into a modular payload to collect on-orbit radiation-response data. Results will refine radiation error-rate models and improves confidence in deploying advanced microelectronics to radiation-rich space environments.

Bit-Flip Sensitivity And Selective Fp32 Protection For Onboard Neural Networks In Flight Software: In-Place Secded Healing Of An Fp32 Weight Buffer Inside Nasa Cfs, Ryan Goodman, Carson Cramer, Braden Eichmeier, Emily Gerber, Christopher Roscoe

Small Satellite Conference

Smallsat missions increasingly deploy neural networks on COTS processors. In orbit, a charged particle striking such a device can flip a single bit of memory, a single event upset (SEU). An upset in a network weight raises no fault condition: the network continues to run, returns incorrect values, and the control loop downstream acts on them. 

The standard cFS response to memory corruption is process restart, which interrupts service and discards runtime state.

In-Transit Debris Remediation: Dual-Use Logistics For Sustainable Cislunar Smallsat Constellations, Wanjiku Chebet Kanjumba

Small Satellite Conference

A Debris Crisis Meets A Logistics Boom: Low- and high-Earth orbit keep accumulating debris faster than the atmosphere can clear it, even as NASA's Artemis and CLPS programs establish routine trans-lunar traffic. The 2009 Iridium-Cosmos collision and later anti-satellite tests proved that single fragmentation events can irreversibly degrade critical orbital shells, raising the specter of Kessler Syndrome. 

• 46,600+ objects tracked on orbit today, with ~130 million sub-cm fragments (ESA, 2025)
• $500K-$2M cost per kilogram for dedicated ADR, fiscally intractable at system scale
• 5-10 / yr large objects must be removed to stabilize LEO (Liou & Johnson)

The Unit-Economics Problem: Purpose-built …

Lessons Learned From The Hyvrid 3u Cubesat Development, Kim Jee Hoon

Small Satellite Conference

Space Object Surveillance System 

• Hanwha Systems’ Next Generation Satellite Laser Ranging (NGSLR) uses the turnaround time of laser emitted from the ground to measure precise distance of satellites or space objects.  
• It is also capable of precise orbit prediction and active response by utilizing high-energy laser. 

Verification Satellite

• CubeSat HYVRID is made to operate as a target satellite of the NGSLR system, verifying the laser ranging, precise orbit prediction, and active response technology.
  • GPS raw data
  • laser detection data
  • images captured before-and-after active response

Numerical Characterization Of Phase Coherence In Distributed Smallsat Sar Interferometry, Cameron Kaminski

Small Satellite Conference

Distributed SmallSat SAR requires independent spacecraft to maintain phase coherence over long integration times. This work presents a Monte Carlo simulation that combines manufacturer-derived oscillator phase noise, spacecraft thermal dynamics, and orbital perturbations to evaluate passive coherence limits. The results show that oscillator quality alone is insufficient; differential thermal-state evolution becomes a dominant driver of long-duration coherence performance.

Polarization-Modulated Laser Satellite Experiment (Pulse-A) Thermal Control, Zane Ebel, Alexavier Moore, Samy Kouidri, Veryan Johnson, Robert Pitu, Juan Ignacio Prieto Asbun, Tian Zhong

Small Satellite Conference

• UChicago's first student-developed satellite, started in September 2023
• Accepted under Batch 15 of NASA's CubeSat Launch Initiative (CSLI) in March 2024
• 3U CubeSat demonstrating space-to-ground optical downlink using circular polarization shift keying (CPolSK)
• LEO, 400-500 km, ~90 min orbit
• Preparing for Critical Design Review in Fall 2026

Aggiesat6 University Cubesat Ops Prep And Leops, Avery G. Barriga, Garrett M. Stevenson, John F. Connolly

Small Satellite Conference

AggieSat6 (AGS6) is a 6U CubeSat designed and developed by students at Texas A&M University (TAMU) as part of the University Nanosatellite Program (UNP) NS-10 cycle. The mission will demonstrate a space-based radio frequency array for Space Domain Awareness (SDA) applications and collect low-energy electron radiation data to improve existing environmental models. Beginning in January 2025, students at TAMU established mission operations architecture, implemented operator training and certification, and prepared to assume sole responsibility for on-orbit operations. The AggieSat6 bus launched into Low Earth Orbit (LEO) in April of 2026. The AGS6 Mission was supported by the University Nanosatellite Program. …

Experimental Analysis Of Cryptography Overhead For Secure Cubesat Telemetry, Tyler Field, Michael Goryll

Small Satellite Conference

Encryption consumes critical and limited resources, such as computing power, energy, and memory. Results from this research has helped SquidSat, a student-led 3u CubeSat launching sometime in 2027-2028, by providing data showing which microcontrollers are most effective for encryption algorithms.

Forecast-Aware Formation Initialization For High-Revisit Vleo Imaging, Mina Khalilzadeh Fathi, Zachary Wrensch, Chaoying Pei

Small Satellite Conference

Very-low Earth orbit (≲ 300 km) enables high-resolution imaging with smaller optics. A leader/follower pair can halve the revisit gap by maintaining precise along-track phasing. 

At 250 km, even a small ballistic-coefficient mismatch amplified by geomagnetic storms drives a phasing error that grows quadratically in time and closes the imaging window within days. 

• Conventional methods focus on formation keeping and react to density after the fact. 
• We act before the drift grows: a density forecast is used to choose both the handover phase and the optimal time to reverse the drift. 

F Prime To Flight Faster: Hardware-In-The-Loop Continuous Integration For Accelerated Cubesat Development, Nate Gay, Saidi Adams, Michael Pham

Small Satellite Conference

Flight software teams iterate quickly in development and then slow down at integration, because the software must be validated against real hardware that is itself still changing. 

Bench testing is manual, intermittent, and happens late. Defects surface days after the commit that caused them, once the context is gone and the change has been built on.

Onboard Ai At The Orbital Edge: A Mission Debrief From Stp-H7-Caspr, Evan W. Gretok, Linus Silbernagel, Diego Wildenstein, Michael J. Cannizzaro, Seth Roffe, Alan D. George

Small Satellite Conference

Goals: Enable autonomous Earth observation and onboard sensor data processing with novel compute

Motivations: Growing numbers of spacecraft demand autonomy in operation and data collection

Challenges: Harsh radiation and thermal environment of space over four-year mission lifetime

Promoting Assured Formation Flight Autonomy Onboard Resource Constrained Systems, Ryan Johnson, Maggie Michelsen, Jackson Gardner, Mario Harper, Charles Swenson, Jackson Kulik, Shawn Jones

Small Satellite Conference

Autonomously determining fuel-optimal, formation-keeping trajectories for small spacecraft operating in formation flight is often limited by available processing power. Because SmallSat missions are constrained by size, weight, and power (SWaP), field-programmable gate arrays (FPGAs) are an attractive option for onboard computing. Traditional formation-keeping relies on convex optimization to solve for fuel-optimal burns and burn times; however, implementing these solvers on FPGAs is challenging due to limited board resources.

To address the need for fast, reliable trajectory planning onboard space vehicles, we investigate leveraging machine learning to reduce computational cost for real-time, onboard execution. We propose using a deep neural network …

Pulse-Q: Space-To-Ground Quantum Key Distribution At The Cubesat Form Factor, Logan Hanssler, Stewart Kristiansen, Ellisian King, Neha Chandran, Unnathi Venkatesh, Selina Gao, Nelson Chan, Mika Sadikario, Joseph Sorel, Lexi Liu, Eleanor Gentry, Rohan Gupta, Juan Ignacio Prieto Asbun, Lauren Ayala, Vincent Redwine, Tian Zhong

Small Satellite Conference

Motivation 

• Quantum key distribution (QKD) offers provably secure communication regardless of the technology available to potential eavesdroppers.
• Space-to-ground QKD facilitates long-distance key distribution without costly terrestrial infrastructure.
• The Polarization-modUlated Laser Satellite Experiment – Quantum (PULSE-Q) is a 12U CubeSat mission to leverage recent innovations in compact quantum sources and optical communication to achieve space-to-ground QKD.

Rapid Integration Of A Secondary Communications Subsystem On Aggiesat6, Alex B. Halbesleben, John F. Connolly

Small Satellite Conference

AggieSat Laboratory (AGSL) is a student-run space program that trains students in systems engineering through hands-on experience in the design, building, testing, and operation of space and space-related systems

AGSL is currently comprised of 107 students, most of whom are undergraduates. Its members work on eight active projects (including a shadow program for underclassmen).

AGSL has demonstrated flight heritage with the deployments of AggieSat2, AggieSat4, and AggieSat6.

Squidsat: A Modular, Open-Source 3u Cubesat Bus For Low-Cost Cubesat Missions, Aaron Bournias, Joseph Dukowitz, Mark Jaber, Tyler Field, Micah Nguyen, Koowum Joshi, Noah Campos, Daphne Riordan, Ryan La Ra, Jonathan Luse, Joshua Sink, Tyler Nielsen, Ricardo Ontivaros, Michael Goryll, Joe Dubois

Small Satellite Conference

CubeSat launches continue to increase yearly, yet over 51% of missions from 2002–2016 failed. Primary faults were often due to power, mechanical, or design issues. Costs still remain high in a market driven by expensive flight-heritage hardware with proprietary designs. In order to counteract such costly practice, Sun Devil Satellite Lab (SDSL) at ASU has developed an open-source, modular 3U CubeSat bus built for low cost reliability. Unlike other bus architectures, SquidSat distributes control across independent microcontrollers linked via a CAN bus. CAN is commanded by the OBC but is capable of independent operation for fault isolation and easier testing. …

The Base Got Hit: Interpersonal Communication Strategies In High-Stress Space Projects, Allison E. Barnes, Avery G. Barriga, John F. Connolly

Small Satellite Conference

The AggieSat Laboratory (AGSL) is a student-driven laboratory with 17 years of space systems experience and flight heritage. As AGSL prepares to launch several space systems over the next three years, reflecting on lessons learned from past projects is critical to improving future reliability and execution. This survey analyzes communication dynamics in past CubeSat and ISS payload projects, specifically within the high-stress phases of Assembly, Integration, and Test (AI&T) and Mission Operations, where a combination of young engineers and high-stakes decision-making can often lead to compounding, avoidable technical anomalies.

This survey identifies specific interpersonal strategies to mitigate human error, including …

Vision-Based Pose Estimation Of A Low-Inertia Robotic Capture Arm, Dane Groves, Willem Jordaan

Small Satellite Conference

The development of CubeSat-integrated robotic arms has expanded the possibilities for In-Orbit Assembly, Repair, and Servicing (OARS). A low-inertia robotic capture arm has been designed previously using remote actuation¹. In the context of CubeSats, this allows heavy actuators to be placed in the base of the CubeSat and lightweight, slender links can be connected to form an arm. This design, depicted in Figure 1, allows for a robotic arm with a low moment of inertia.

The limited 6.5 mm link profile prevents the integration of high-resolution joint encoders, motivating the use of an alternative state estimation technique. This …

Plasma Magnet Propulsion For Smallsat Deep Space Missions: Scaling Laws, Trajectory Analysis, And A Path To Flight Demonstration, Surya S. Kalluri

Small Satellite Conference

The plasma magnet uses a rotating magnetic field (RMF) to drive azimuthal currents in ambient plasma, inflating a spacecraft dipole to kilometre scale so momentum is taken directly from the solar wind. Using plasma currents in place of physical coil proposed for similar concepts previously like Magnetosail, M2P2 etc., eliminates the constraints on size and dynamic pressure of seed plasma. Because the inflated plasma — not a structure — sets the obstacle size, thrust is independent of distance from sun while the required power falls as the antenna grows. Earlier experiments showed >10 kA driven currents, inflation beyond ten coil …