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Augmenting Attitude Knowledge for Optical Communication Terminals on CubeSats by Kalman Filter Based Estimation
Get PDFGiven the growing demand for high data rate transmission on small satellites like CubeSats, free-space optical communication terminals have recently attracted an increasing interest thanks to their capability of ensuring high data rates, compact designs and low power requirements. Yet, the performances of the acquisition and pointing processes crucially depend on their attitude knowledge information. This information is currently available only if an optical link has already been established. Nevertheless, it is likewise important to accurately know the attitude during the link acquisition phase to shorten the search time until the opposing target is found. This aspect is equally relevant in the context of Inter-Satellite Links between CubeSats and for enhancing Direct-To-Earth communications.
Indeed, this work presents an attitude estimation concept for CubeSats housing Laser Communication Terminals (LCT), aiming to augment the system’s attitude knowledge to establish optical links and maintain them over time.
Linear extrapolation and quaternion kinematics propagation have been initially investigated for a basic estimation relying on the CubeSat’s ADCS telemetry. Hence a more sophisticated algorithm has been developed consisting of a USQUE Unscented Kalman Filter according to the model of Crassidis and Markley, 2003. This proposed algorithm relies on the attitude information given by the CubeSat’s ADCS as well as on the measurements coming from the LCT’s sensors. A comparative analysis between the algorithms has been undertaken for a dynamic and a stable scenarios in terms of pointing accuracy to investigate the improvement achieved by exploiting the Kalman filter and the information of the LCT.
From simulations, the Kalman filter-based estimation algorithms proved to grant a fast convergence and an accurate estimation of the CubeSat’s attitude. Thanks to this augmented knowledge that relies on the LCT information, it is hence possible to shorten the search time needed to establish an optical link and to easily compensate for pointing errors during the tracking phase of the mission
A Torrent-Inspired Large File Transfer System for Small Satellite Swarms
Get PDFThe increasing complexity and coordination requirements of multi-spacecraft missions, distributed space systems, and small satellite swarms necessitate efficient and scalable data transfer mechanisms. Inspired by peer-to-peer file sharing protocols, we present a novel large file transfer (LFT) system designed for NASA’s Core Flight Software (cFS) framework. The LFT system was tested on NASA’s Starling mission, a multi-cubesat swarm with S-Band cross-link capabilities and a mesh network topology. Our system leverages the Better Approach to Mobile Ad-hoc Networking (BATMAN) routing protocol and the Data Distribution Service (DDS) standard to enable seamless communication among swarm members. The LFT system features two primary use cases: push data, where a sender initiates a transfer session by broadcasting data packets to targeted receivers, and request data, where a receiver solicits specific data from other swarm members. We demonstrate the effectiveness of our torrent-inspired approach in facilitating strategic coordination and large file transfers onboard the Starling spacecraft via the crosslink network. Our system’s scalability, fault tolerance, and adaptability make it an attractive solution for future small satellite swarms requiring efficientdata exchange capabilitie
Optical Inter-Satellite Link Demonstration on CubeSats - Update on the CubeISL-IOD Mission
Get PDFFree-space optical communication has become a mature technology to extend and replace classical radio channels for data transmission from satellites to the Earth. The advantages of high data throughputs, resilience against electromagnetic disturbances and its robustness against jamming spoofing and eavesdropping makes laser communication attractive for governmental, defense authorities and commercial users. To enable global connectivity and interoperability beyond the line of sight, inter-satellite links are required and therefore terminals with high data rates are necessary to avoid communication bottlenecks. Size weight and power limitations on spacecraft demand highly efficient and miniaturized payloads, especially for use cases on smallest satellites.
The German Aerospace Center (DLR) developed laser communication terminals especially designed for CubeSats. The next step is to ransfer this technology from direct-to-Earth into the inter-satellite domain. Thus, DLR developed the CubeISL terminal to establish an optical connection between two identical terminals to exchange information with a data rate of 100 Mbps over distances of up to 1,500 km. The standardized formfactor of just 1U allows easy and simple integration into standard CubeSat busses and the separation of the receiver and transmitter signal by wavelength allows building up constellations containing multiple satellites.
The capabilities of the CubeISL terminals will be demonstrated in a relevant, operational scenario on two 6U CubeSats built by the Spanish company Alén Space. The mission is led by Responsive Space Cluster Competence Center and the satellites will be operated by the German Space Operations Center, both as parts of DLR.
This paper gives an update on the latest state of the project. It depicts the status of the terminal development as the key component of the in orbit demonstration mission. The two carrier platforms are described briefly and their concept is explained. Laser communication is highly dependent on the pointing performance and a stable orbit control. In addition, the capabilities of the optical connection will be demonstrated and evaluated in different distances. All this leads to strict requirements for the satellites, especially for the attitude and orbit control system. The concept to achieve this precision and accuracy is briefly discussed.
Furthermore, the paper describes the mission architecture and the operations concept. Different communication standards used in the terminal, the satellite and the ground segment require an aligned coordination of the protocols and standards. Alén Space will take care of the satellites during the launch and early orbit phase and hand over the satellite to DLR afterwards. This transition and the following operations concept of the laser experiments are briefly discussed as well
Women in the Workplace: Part 2: Utahns’ Awareness, Understanding, And Attitudes
No full textDuring the fall of 2023, Utah Women & Leadership Project (UWLP) researchers conducted a statewide study to establish a baseline for public perceptions related to the awareness, understanding, and attitudes about challenges that Utah women and girls face. In early 2024, we published 20 short research summaries1 that shared the results of this comprehensive study. Then, in the fall of 2024, we administered this survey, with slight changes, around the state of Utah for the second time. This is the second of six white papers to share the results of the new data.
Overall, this comprehensive study was designed to support the efforts of A Bolder Way Forward (BWF), which is a statewide initiative focused on ensuring that more Utah girls, women, and their families thrive. Each area of focus (imagine the areas as spokes on a wheel) has bold goals with data-driven metrics to measure progress. This research focuses on collecting and analyzing data to help track this progress for those goals based on potential shifts in public awareness, understanding, and/or attitudes related to each spoke. The shifts are critical for Utahns to make progress in the topic areas.
The following lists the five overarching categories within BWF and the 18 spokes included in this research: Education: Finance, Higher Education Attainment, and K–12 Initiatives Community Engagement: Political Representation, Boards and Commissions, and Civic Engagement/Advocacy Safety and Security: Child Sexual Abuse, Domestic Violence, Poverty and Homelessness, Sexual Assault, and Sexual Harassment and Gender-Based Discrimination Health and Wellbeing: Health Across the Lifespan, and Home and Family Workplace: Childcare/Pre-K Programs, Entrepreneurship, Gender Pay Gap, Leadership Development, Organizational Strategies and Workplace Culture, STEM Fields, and Workforce Development
This report covers elements of four spokes in the Workplace category: Entrepreneurship, Workforce Development, STEM Fields, and Leadership Development. The results of the three other Workplace spokes (i.e., Organizational Strategies & Workplace Culture, Childcare/Pre-Kindergarten Programs, and Gender Pay Gap), in addition to one from the “Safety & Security” spoke (i.e., Sexual Harassment & Gender-Based Discrimination), are included in the first white paper in this 2025 series titled “Women in the Workplace: Part 1 – Utahns\u27 Awareness, Understanding, and Attitudes.” After highlighting foundational research methods for the study as a whole, this report shares the findings of these four areas of focus and includes both the applicable quantitative and qualitative results
Home, Health, Community, & Allyship: Utahns’ Awareness, Understanding, And Attitudes
No full textDuring the fall of 2023, Utah Women & Leadership Project (UWLP) researchers conducted a statewide study to establish a baseline for public perceptions related to the awareness, understanding, and attitudes about challenges that Utah women and girls face. In early 2024, we published 20 short research summaries that shared the results of this comprehensive study. Then, in the fall of 2024, we administered the survey, with slight refinements, around the state of Utah. We now share the results of the 2024 data by releasing six white papers; this is the fifth in the series.
Overall, this comprehensive study was designed to support the efforts of A Bolder Way Forward (BWF), which is a statewide initiative focused on ensuring that more Utah girls, women, and their families thrive. Each area of focus (spoke) has bold goals with data-driven metrics to measure progress. This research focuses on collecting and analyzing data to help track this progress for those goals based on potential shifts in public awareness, understanding, and/or attitudes related to each spoke. The shifts are critical for Utahns to make progress in the topic areas.
The following lists the five overarching categories within BWF and the 18 spokes included in this research: Education: Finance, Higher Education Attainment, and K–12 Initiatives Community Engagement: Political Representation, Boards and Commissions, and Civic Engagement/Advocacy Safety and Security: Child Sexual Abuse, Domestic Violence, Poverty and Homelessness, Sexual Assault, and Sexual Harassment and Gender-Based Discrimination Health and Wellbeing: Health Across the Lifespan, and Home and Family Workplace: Childcare/Pre-K Programs, Entrepreneurship, Gender Pay Gap, Leadership Development, Organizational Strategies and Workplace Culture, STEM Fields, and Workforce Development
This report covers two spokes in Health and Wellbeing (i.e., Home and Family, and Health across the Lifespan), as well as the Political & Civic Representation Spoke. In addition, it concludes with findings from survey items and qualitative responses focused on allyship. Although male allyship is not a BWF spoke, the support of men is critical for change to happen in terms of ensuring that more Utah girls and women thrive. Hence, we included four related survey items to track perception changes across time. In that portion of this report, we also present qualitative findings on women supporting each other as allies. After highlighting foundational research methods for the study as a whole, this report shares the findings of these four areas of focus and includes both the applicable quantitative and qualitative results
From Rifles to Running Shoes: How Outdoor Recreation Trends are Reshaping Conservation Efforts
No full textParks and protected areas (PPAs) serve a dual purpose: they conserve wildlife and natural habitats while providing spaces for people to enjoy outdoor recreation. However, balancing conservation with recreation can be challenging, especially as outdoor activities continue to grow and evolve. In Utah, Wildlife Management Areas (WMAs) are set aside to protect important wildlife habitats and provide opportunities for hunting and fishing. Recently, these areas have seen an increase in activities such as mountain biking, trail running, and dog walking, some of which take place in areas which prohibit recreational activity in effort to protect wildlife. These shifts in recreation patterns raise important questions about how human activities impact wildlife and how best to encourage responsible outdoor behavior.
This study explores how people\u27s values about wildlife and their participation in hunting and fishing relate to their stewardship behaviors, such as following Leave No Trace (LNT) principles. Specifically, it examines connections between people\u27s wildlife value orientations, status of holding a hunting or fishing license, and environmental stewardship behaviors.
A significant relationship emerged between license status and stewardship, with those who never held a hunting or fishing license reporting a small but significantly greater intent to follow LNT principles. Additionally, non-license holders were significantly more likely to have mutualist values. A review of existing research suggests that LNT practices can help reduce recreational impacts on wildlife, but more studies are needed to understand these effects fully.
As outdoor recreation continues to grow, this research highlights the importance of promoting stewardship and responsible recreation. By understanding how people\u27s values correspond with their conservation behaviors, land managers can develop strategies that encourage responsible outdoor recreation while protecting wildlife and natural areas. Through education, policy, and engagement, we can ensure that these landscapes remain places where both people and wildlife can thrive
Passively Deployed PCM Radiator Panels for CubeSat Thermal Management
No full textThis work presents a passive actuation approach for internally stored fins equipped with a phase change material (PCM), enabling a dynamic response to waste heat loads and environmental conditions. The fins can achieve semi-deployed or fully deployed positions. The radiator system absorbs heat from the CubeSat and rejects it into the environment. Modeling progress in Thermal Desktop is presented, with emphasis on lessons learned from transient actuation simulations and PCM performance
Two-Way Shape Memory Alloy Heat Pipes for Passive Radiator Actuation
No full textWhen passively actuated in response to changes in CubeSat temperature, deployable radiators are capable of thermal regulation without the need for an electrical control system. However, these radiators face challenges in the transfer of heat from the CubeSat interior to the deployed radiator panel. In this work, we explore an approach that provides passive radiator actuation and efficient thermal transfer by combining a Two-Way Shape Memory Alloy actuator with an integrated heat pipe. Preliminary work focuses on the characterization of the Two-Way Shape Memory Effect (TWSME) in bending of Nitinol rods and tubes of varying outer diameters
Periodic Test Signals for Measurement and Calibration of Phase Modulated Signals Directly With Spectral Analysis
No full textSoftware Defined Radio (SDR) transmitters that employ digital phase modulation can have imperfections in the transmitted waveform that either distort the intended signal or introduce undesired spurious interference. In the case of zero-intermediate frequency transmission, these impairments include amplitude imbalance between the in-phase and quadrature components, quadrature skew in the vector modulator, and local oscillator feedthrough. In the case of heterodyne transmission, where the digital modulation is applied to a carrier offset before digital-to-analog conversion, an undesired image may be present at the vector modulator output. These transmitter impairments can be observed and measured directly with a vector signal analyzer (VSA), which can also allow the engineer to visualize the digital modulation in the form of constellation plots or eye diagrams. Although it is possible to overcome poor modulation characteristics with greater transmitted power, this option is prohibitively expensive in small satellite communication links. It is preferable to develop techniques for tuning out suboptimal modulation characteristics. If VSA equipment is not available, a series of simple periodic test signals synthesized in the SDR transmitter can allow an engineer to measure the same imperfections directly with a simple spectrum analyzer. Even if the VSA is available, the measurement of test signal outputs on the spectrum analyzer can provide independent confirmation of the VSA results. Furthermore, the test signal sequence can also be used to calibrate out the effects with the introduction of predistortion in the transmitter. This paper illustrates the use of an ordinary spectrum analyzer in the measurement of phase modulation imperfections, and highlights calibration techniques to remove them. Emphasis is placed on binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), and offset quadrature phase shift keying (OQPSK). The appropriate test signals to use for each case are identified, and the theoretical spectrum for each signal is derived. Examples of imperfections and the effects they have on the test signal spectrum are shown and interpreted, and the spectral analysis technique measurements are then compared to VSA results
Pathways to Higher Education: Expanding College and Career Access for Rural Youth
Get PDFIn June 2025, Utah State University (USU) Extension hosted a two-day event, Pathways to Higher Education. The event introduced 31 rural youth from Grand County and San Juan County to USU educational opportunities and careers through immersive tours and workshops, visiting the Price, Moab, and Logan campuses. Participants reported increased college confidence, financial aid awareness, and career interest. Evaluation showed strong engagement, improved participants’ understanding of higher education pathways, and increased confidence in preparing for postsecondary education