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TWISTR: A Scalable, Low-Cost Microsatellite Rotation Device for Spacecraft Assembly Integration and Testing
Get PDFIncreased industry demand for microsatellite missions calls for aggressive project timelines without sacrificing intricate development practices. Delivering missions at a faster pace relies strongly on both assembly processes, and ground support equipment, used through mission development cycles. Procedural challenges often arise in positioning larger spacecraft within the laboratory environment for various testing campaigns. Deployable mechanism, vibration, thermal vacuum, and electromagnetic compatibility testing often require spacecraft to be held under multiple orientations. Dual-axis rotation devices offer a means to position spacecraft in any orientation, proving a versatile spacecraft assembly, integration, and testing platform.
The development of a low-cost dual-axis rotation device is presented for use in microsatellite assembly, integration, and testing. The Test Workstation for Integration of Spacecraft Technology and Rotation (TWISTR) will enable functional and environmental testing of a 60-kg microsatellite mission. As such, the device is designed and tested to meet applicable ground support system requirements for use at various launch vehicle integration sites.
TWISTR facilitates dual-axis rotation using a crossed roller bearing mounted orthogonally to an automotive engine stand. Primary axis rotation is driven by a worm gear within the engine stand assembly to prevent back driving. Secondary axis rotation is accomplished by operator intervention on the unconstrained bearing, and the angle can be fixed in discrete increments using a spring-loaded tapered pin. A cradle structure enables the crossed roller bearing to be mounted orthogonally to the engine stand. The cradle structure is designed with members dedicated to supporting orthogonal bending modes associated with various orientations. This allows for future design scalability, as the structural design performance can be adjusted through the sizing of only six structural members.
Finite element analysis is conducted to verify the sizing of the cradle structure for a 60-kg satellite with consideration for future missions. The pin taper angle of the secondary axis locking mechanism is selected such that the mechanism cannot slip out of engagement regardless of the mass or mass center of the spacecraft. Sizing of the taper pin is accomplished through leveraging stress concentration factors in literature to compute contact stresses at the tip and root of the pin.
Proof load testing is conducted with loads in excess of the baselined 60-kg microsatellite, as to certify the design for use with future missions. Testing methodologies and justification is presented herein
Framing Conflict: How Social Media Influences Voter Opinions
No full textSocial media has changed the way we learn about global events. With just a few clicks, people can see powerful images of war and humanitarian crises from around the world. But how do these images, and the way they are presented, affect how people think about political candidates? This study looks at how different kinds of social media content influence voter opinions. Using a survey experiment designed to mimic real Instagram posts, participants were shown content related to the Israel-Palestine conflict. Some posts included only text. Others added data through charts and statistics. A third group saw emotional images of destruction combined with the same data.
The results indicate that how information is framed matters. People who saw the emotional images were less likely to support the fictional candidate featured in the posts. In contrast, those who saw only data were more moderate in their responses. The study also found that people who spend a lot of time on social media were generally less supportive of the candidate overall, suggesting that constant exposure to political content can lead to emotional fatigue or skepticism.
This research helps us understand how modern political communication works. As voters get more of their news from platforms like Instagram, the way messages are shared can shape opinions in powerful ways. For political campaigns, journalists, and advocacy groups, these findings offer insight into how to communicate effectively in the digital age. At the same time, the study raises questions about how emotional or data-heavy content can influence public opinion, especially on sensitive global issues. Understanding these effects is important for promoting informed and responsible political discourse
Evaluating Cyanotoxins in Surface Water and Aerosols Near Utah Lake
Get PDFUtah Lake is a freshwater lake in Utah County near Provo, Utah. It is the third- largest lake in Utah and is important for recreation and local businesses. However, from June to October, the lake often has cyanobacteria harmful algal blooms (cHABs), which contain a toxin called cyanotoxin. These toxins can be dangerous to people who come into contact with the water. Government agencies regularly check for cHABs and warn people when the water is unsafe for activities like swimming. Collecting water samples to test for cHABs can be risky because it can possibly result in direct contact with the contaminated water. In addition, it is possible for the cyanotoxins to become airborne and spread through the air, which could be harmful if people breathe them in. However, monitoring the air for cyanobacteria is not currently done at Utah Lake. This study aimed to discover if cyanotoxins in Utah Lake could become airborne and if using a remote- controlled boat could collect water samples similar to a human. Researchers collected water and air samples at two locations—Lincoln Marina and Utah State Lake Park— during the summer of 2024. Water samples were taken daily around noon using both traditional methods and a robotic boat with a water sampler. Air samples were collected onto air filters using vacuum-based air samplers that ran for 8–12 hours each day. The collected samples were analyzed using a method approved by the U.S. Environmental Protection Agency (EPA). The results confirmed that the robotic boat was effective at collecting water samples. More importantly, researchers found that cyanotoxins were present in the air near the lake at levels similar to other studies. The study also showed that wind speed, wind direction, and water movement played a big role in spreading the bacteria into the air. These findings highlight the need for more research and monitoring of airborne cyanotoxins to better understand the potential health risks for people near Utah Lake
Examining the Predictive Validity of Adolescent Complete Mental Health on High School Academic Performance
Get PDFThis multiple-paper dissertation examines how adolescent complete mental health, based on the Dual-Factor Model, predicts high school academic performance. The Dual-Factor Model considers both psychological distress (such as internalizing and externalizing symptoms) and subjective wellbeing (such as life satisfaction and positive affect). The main research objective is to determine whether this comprehensive framework offers stronger predictive power for academic success than symptom-based approaches alone.
Two studies were conducted using self-report mental health data collected at three time points during an academic year. These data were analyzed alongside end-of-quarter grade point averages in English Language Arts, math, and overall GPA using multilevel modeling. The analyses controlled for relevant demographic and school-level covariates.
Results suggest that subjective wellbeing contributes uniquely to academic performance, even when accounting for emotional and behavioral symptoms. Students with higher levels of wellbeing tended to earn better grades, regardless of whether they showed clinical signs of distress. These findings support the integration of strength-based mental health screening and interventions in school settings.
The results advocate for the use of continuous, dual-factor screening models in schools to move beyond a purely deficit-based focus. By assessing both student strengths and symptoms, schools can implement more comprehensive interventions that cultivate well-being while addressing mental health problems, thereby supporting students\u27 holistic development and academic achievement
The Recreation Opportunity Spectrum in Practice: A Classification of Visitors and Sites in the Roaring Fork Valley, Colorado, USA
No full textResearchers and public land managers continue to investigate what motivates visitors to recreate and how to best sustain environmental conditions to provide for these recreation demands and support conservation goals. Much recreation research has successfully identified visitor motivations at a single recreation area (spatial scale), but few studies broadly assess the manifestation of visitor motivations at an array of recreation areas that present unique recreation experience opportunities. Additionally, it is known that there are a diversity of visitor motivations and preferences, which presents a complex challenge to public land managers who must ensure that a diversity of recreation opportunities are available across a multitude of recreation areas. It is important to understand this variety in visitor motivations and preferences to support land managers’ efforts to develop and implement tailored strategies for managing outdoor recreation that provide for the desired visitor experience and ensure the recreation areas across larger spatial scales sufficiently provide diverse recreation opportunities. I intend to understand the comprehensive visitor experience and diversity of recreation opportunities provided for at recreation areas in the Roaring Fork Valley in western Colorado. In Chapter Two, I categorize the 14 recreation areas of interest along a five-level spectrum of experience opportunity classes and analyze visitor survey response data collected at these sites to identify key visitor motivations and gauge visitor response scores to a suite of questions about crowding perceptions and any subsequent coping behaviors. I further analyzed the relationship between these constructs and the recreation area groupings to understand how the visitor experience varied across the spectrum of sites. In Chapter Three, I utilize multi-variate data from rapid-field assessments to empirically group 52 recreation areas and develop comprehensive group profiles to understand the nuance of recreation opportunities provided in the Roaring Fork Valley. From these efforts, I conclude that visitors across the spectrum of recreation areas report a motivation to experience nature and tranquility, suggesting a shared desire for nature based experiences. Additional findings suggest that there is a diversity of recreation opportunities available that provide for the variety of visitor preferences in the Roaring Fork Valley
Evaluating the Effects of Two Key Temporal Intervals During Pavlovian Training on Conditioned Reinforcement
Get PDFReinforcers are anything that increases or maintains the frequency of a behavior that precedes their occurrence. Reinforcers can be separated into two types, primary and secondary. Primary reinforcers are biologically relevant stimuli like food, water, or drugs that can influence behavior without any prior training. Secondary reinforcers are those that impact behavior through their trained relationship with a primary reinforcer, like money and tokens. For this reason, they are also known as conditioned reinforcers. Conditioned reinforcers are used in therapies and training designed to increase desirable behaviors, but they are also involved in the development and maintenance of maladaptive behaviors such as drug use and overeating. To both increase effectiveness of behavioral therapies and reduce maladaptive behaviors, we must fully understand the factors that result in the development of effective conditioned reinforcers. To that end, the experiments in this dissertation examined a wide range of temporal variables during training of the relationship between the intended conditioned reinforcer and primary reinforcer thought to be critical in the development of strong conditioned reinforcers. Chapter 2 examined the relationship between the duration of time between training trials and conditioned reinforcer efficacy. It was previously thought that this relationship should be linear, with longer intervals resulting in better conditioned reinforcer efficacy. Instead, the results showed that the relationship broke down at very long intervals. A mathematical model was developed to account for this breakdown. Chapter 3 tested a different interval, the time between presentation of the intended conditioned reinforcer and the primary reinforcer. A breakdown was also observed at intervals predicted to produce strong reinforcers, which was not accounted for by the model proposed in Chapter 2. These results have important implications for those who wish to use conditioned reinforcers in behavioral treatments and present new questions about the ideal conditions in which a conditioned reinforcer is trained
I was in the Story : The Relationship of Oral Storytelling With Student Hope, Narrative Transportation, and Religious Beliefs
No full textThis study investigated the potential relationships with oral storytelling and student narrative transportation levels, student hope levels, and student religious beliefs. The Children’s Hope Scale and the Transportation Scale-Short Form were to assess hope levels and narrative transportation levels in participants. Results suggest that oral storytelling may have a strong relationship with narrative transportation. A relationship with oral storytelling and student religious beliefs is also suggested. Oral storytelling and student hope levels, and the possible connection between student narrative transportation levels and student hope levels, needs further research
Orbital Motion Coordination Using Bio-Inspired Optical Sensing and Feedback
Get PDFSummary: Multi-satellite coordinated missions can improve upon larger solitary satellite missions through greater flexibility, efficiency, scalability and redundancy. This study considers a more diverse approach to in-orbit motion coordination that reduce dependence on communication links and absolute position references. The non-linear relative equations of motion applied to a chief satellite and a deputy target in the LEO orbit are considered and a feedback control system to facilitate multi-satellite relative motion coordination is designed. The feedback controller relies on on-board optical sensor measuring optic flow signal, similar to the bio-inspired feedback-controlled systems used for various aerial operations. Performance in orbit is analyzed by means of multiple numerical simulations on a rendezvous scenario with a target in LEO orbit. A ground-based experimental testbed is designed for validation of the feedback control framework for space- borne optical systems
The Remote Capability-Auctioning Planner (ReCAP): A Decentralized Multi-Agent Control System Using Classical Planning, Behavior Trees, and Remote Task Auctions
No full textPoster presented during the 2025 SmallSat Conference
Launch Fast Learn Fast: Lessons Learned From the R5-S2 and R5-S4 Missions
No full textThe Realizing Rapid, Reduced-cost high-Risk Research (R5) project is pushing the envelope on minimizing cost and schedule for complex spacecraft that support low Technology Readiness Level payload demonstration in Low Earth Orbit (LEO). R5 has recently designed, built, launched, and operated multiple spacecraft that are iteratively and incrementally delivering improved payload hosting capabilities while maintaining cost targets (\u3c $100k in materials per bus) and schedule targets (launching at least two spacecraft per year). This paper will describe the unique architecture, approach, technological advancements, and lessons learned from the project. The primary stakeholder for R5 is the Small Spacecraft Technology program within the Space Technology Mission Directorate at NASA with the project based out of Johnson Space Center.
To achieve the aggressive cost and schedule targets, R5 is redefining the understanding of how much rigor, quality, and robustness are required to succeed in high-risk LEO missions. Starting with a clean-slate for process and system design, R5 has charted a path, subsystem by subsystem, through commercial, industrial, automotive, and medical- grade components to arrive at a functional baseline bus that includes high-performance onboard computing, six degree-of-freedom control from a cold-gas propulsion system, automated mission operations, and other capabilities. R5 has also accounted for regulatory schedule impacts in its architecture development, which includes using communication systems that are faster to approve through the regulatory process. R5 Spacecraft 2 (R5-S2) and R5 Spacecraft 4 (R5-S4) are the first two R5 spacecraft to successfully make it to orbit. These spacecraft, which contain no space-rated components, quickly exceeded their minimum mission success criteria and operated throughout their 10 month mission lifetime in orbit. The data gathered during the mission and its consideration for the next generation of R5 spacecraft is covered below.
By its very nature, R5 is constantly learning lessons regarding component suitability, process, and architectural design decisions and their impact on the project’s goals. R5 has captured more than 70 lessons learned that span all subsystems and phases of spacecraft development and operations. R5 tracks the infusion of the lessons learned into the broader space community as a success metric. This paper provides details on lessons learned with the goal of enabling teams across the industry to leverage these lessons to improve their own cost, process, and schedule