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An Introspective Understanding of Livestock Movement
Get PDFThis fact sheet creates a framework for understanding how human presence influences the movement of livestock animals. Although this work references sheep and cattle, the introspective approach to understanding livestock movement can be applied to a variety of livestock species. This fact sheet highlights self-confidence in livestock handling and training through calm working experiences
Righting Reproductive Wrongs: A Rhetorical Analysis of Special Topoi in Alberto Fernández’s Pro-Voluntary Interruption of Pregnancy Speeches
Get PDFThe reproductive rights movement argues that abortion rights are fundamental and necessary for women to enjoy their human rights. Politicians opposed to abortion rights around the world have made it clear that they plan to ban abortion both statewide and nationwide. A country that has proven to be successful in defending its reproductive rights is Argentina. In 2020, the Voluntary Interruption of Pregnancy Bill (Interrupción Voluntaria del Embarazo; IVE) democratically passed and legalized abortion throughout Argentina. Argentine President, Alberto Fernández, supported IVE and delivered a series of speeches over four years highlighting IVE and the progress that has succeeded each year. In this study, I critically analyze Fernández’s four pro-IVE speeches in search of the special topoi. I found that Fernández returned to stability, positive change, and collective health when arguing in favor of IVE
Fruit Consumption Indicators: Who Consumes More Fruit in Utah?
Get PDFThis fact sheet discusses fruit consumption patterns in Utah, exploring the key demographic and socioeconomic factors linked to increased fruit intake. Fruit growers and marketers can use this information to design effective promotional campaigns targeting consumers more likely to purchase fruit and fruit products
Horizontal Link Demonstration Over 143 km With CubeISL: The World\u27s Smallest Commercial Optical Communication Payload for Inter-Satellite Links
Get PDFNew developments in the field of free-space optical (FSO) communications are enabling a breakthrough in satellite miniaturization and data rates. The CubeISL laser communication terminal (LCT), developed by the German Aerospace Center (DLR), shall demonstrate in-orbit inter-satellite links (ISLs) at 100 Mbps and downlinks at 1 Gbps. When it launches in 2025, it aims to become the state-of-the-art technology for efficient CubeSat communications at high data rates and the world\u27s smallest optical inter-satellite link terminal.
The performance of the CubeISL terminal was tested in a 143 km horizontal link between the islands of La Palma and Tenerife. In this setup, the transmitter from the LCT was used to characterize the atmospheric aberrations of the horizontal link using the ESA Optical Ground Station. Additionally, another LCT was used to demonstrate the tracking capabilities between two CubeISL terminals. This paper describes the current development status that allowed achieving an inter-island link. It analyzes the atmospheric aberrations encountered among the horizontal link and presents the results from the tracking performance between the two ISL terminals.
The focus of the paper lies specifically on the system\u27s design which allows effortless transportation, swift assembly, and eye-safe operation. This design enables a pragmatic automatization of FSO links with CubeISL in flexible terminal–OGS configurations and campaign sites
Low-Latitude Ionosphere/Thermosphere Enhancements in Density Mission (LLITED): Results and Challenges
Get PDFThe Low-Latitude Ionosphere/Thermosphere Enhancements in Density (LLITED) mission, a two 1.5U CubeSat mission to study nighttime ionosphere/thermosphere coupling, was successfully launched in the spring of 2023. While the CubeSats successfully reached orbit, the final orbit differed from the planned orbit. Both LLITED-A and LLITED-B spacecraft completed early orbit check out and commissioning, but due to a solar cell anomaly are operating with a significant reduction in power. This has resulted in a much lower duty cycle for each of the three science payloads: an ionization gauge (MIGSI) to observe neutral density, a planar ion probe (PIP) to observe plasma density, and a GPS radio occultation sensor for observing (CTECS-A) total electron content. The combination of the operating orbit and power budget has required a refocusing of the mission science goals and a highly tailored ConOps. Despite these challenges, LLITED-A/B has provided exciting observations of small-scale density structure evolution, neutral atmospheric variability across the cusp boundary, and neutral and plasma density structure coupling
The Any% Method – Improving Space Access Through Improved Design, Build, and Test Methodologies
Get PDFOne of the seminal problems that faces new and academic CubeSat teams is very long development cycles that often lead to project failure through some combination of funding issues, launch window misses, and loss of gained institutional knowledge. While many are familiar with the approximately 40% early failure rate of launched CubeSats, this metric only tracks missions that actually made it to dispenser integration. In our tracking of approximately 35 university teams since 2019, we have found that only 4 have successfully launched in that time, implying that 88% of aspiring CubeSat programs fail before they even make it to launch. We believe that this is an unacceptably high rate of failure for this community and propose that a major shift in how CubeSat engineering is conducted may significantly reduce this gap between the number of institutions who desire to participate in the space industry and the number that are actually able to.
We seek to present lessons learned from the development of the PROVES Kit at Bronco Space lab, Cal Poly Pomona, which launched three unique 1U CubeSats on three back-to-back SpaceX Transporter flights between January and June 2023. Notably, the total cost for these satellites (including launch) was only $106k, with the fastest development cycle completed in under a week.
A core finding of our retrospective analysis of this run of satellites is what we refer to as the “Any% Method.” We advocate for a more dynamic approach to lean space mission engineering, focusing on just achieving the specific end goal of the mission even at the expense of only partially completing other objectives. This “Any%” completion methodology can be combined with multiple design, build, test cycles. This repetition, even if only one success is required, provides invaluable experience, refining each subsequent attempt. We believe this strategy not only accelerates pace towards meeting project objectives but also enhances the educational and developmental aspects of the program, potentially increasing the success rate of university-led CubeSat projects
A Building Block Approach to Satellites and its Impact on Changes in Late AI&T Athena – A Case Study
Get PDFThe Space Force, NASA, and NOAA partnered to fly the pathfinder Athena climate-change mission using NovaWurks’ building block approach to demonstrate a new way to build and fly sensorcraft. This mission to measure Earth Radiation Budget was originally planned for launch in 2023 on a LauncherOne rideshare. Due to cessation of Virgin Orbit launch operations, Athena was shifted to a Falcon 9 with a different LTAN. The change from 1300 to 1800 in a sun-synchronous LEO orbit dramatically impacts the solar illumination of the satellite and frequency/duration of eclipse, resulting in severely impacted CONOPS. NASA asked NovaWurks whether the vehicle could be reconfigured to accommodate the new LTAN in just a few months. The eight identical blocks were rearranged to allow the sensor to operate effectively in the new orbit. Launch is now planned for later this year. The paper will show how the physical arrangement changed dramatically after it had already been delivered for integration, along with the minimal steps required to make a major change in a short time.
From the outset, the building block approach allowed the NASA sensor to be significantly simplified, which was a major consideration for NASA. In addition, the building block approach simplified the payload by using capabilities integral to the blocks. The NASA sensor is taking advantage of the building blocks’ ability to gimbal the payload to scan the earth. The blocks also process and store data before transmission to the ground.
While redesigning an already-built satellite would be costly and time consuming, the building block approach allows resolution of unexpected changes which may occur late in I&T. In a Sun Synchronous Orbit (SSO), Athena’s original configuration enabled the sensor to point NADIR 100% of the time, gathering data continuously. Without reconfiguration, the LTAN change from 1300 to 1800 would severely impact the duty cycle due to solar illumination angles on the arrays. A simple reconfiguration permits mission requirements to be met in the changed orbit.
The entirety of the reconfiguration consists of updating drawings and fabrication of a few mechanical items. This whole process can happen in a matter of weeks and at any point in the I&T timeline.
This is not the first time NovaWurks blocks enabled a configuration change late in the I&T cycle. On the 2018 SSOA rideshare, the NovaWurks eXCITe spacecraft was reconfigured to satisfy the rideshare Coupled Load Analysis. Note, eXCITe met all LV requirements as it was. The change was made to accommodate the launch provider and rideshare neighbors. Once on orbit, the spacecraft self-deploys to final configuration, so the launch configuration can be completely different.
This paper will describe the reconfiguration of NovaWurks’ spacecraft on the ground, which successfully resolved external impacts on eXCITe and Athena. It will also describe In Space Assembly and Manufacturing (ISAM), allowing vehicles to be reconfigured, or built, in space
Cold-Infusion of Catalytic Materials Into 3-D Printed Fuels for In-Space Hybrid Propulsion Performance Enhancement
Get PDFA recent study by the ESA Space Research and Technology Center has identified that reducing toxicity of propellants offers the highest potential for reducing commercial space operating costs. Developing a green alternative for hydrazine, the most commonly used space propellant, was highly recommended. Hybrid propulsion offers an emerging, low-cost solution, especially for SmallSat propulsion.
Historically, a primary drawback of hybrid systems was a lack of reliable multiple-use ignition methods. Recently, restartability issues were overcome by leveraging unique dielectric breakdown properties of 3-D printed acrylonitrile butadiene styrene (ABS). Additive printing significantly changes thermoelectric properties, and when ABS is subjected to an electrostatic potential, the layered structure allows arc-tracks to be carved between the electrodes. Associated Joule-heating pyrolyzes fuel, allowing ignition to spontaneously occur when oxidizer flows.
Arc-ignition has been harnessed to develop a High-Performance Green Hybrid Propulsion (HGHP) family that has capability for reliable on-demand start, stop, and re-ignition. In its most mature form, HPGHP uses gaseous oxygen (GOX). However, unless stored at very high pressures, GOX has low-density, and it is highly desirable to employ higher density, long-term storable oxidizers, such as high-test hydrogen peroxide (HTP), nitrous oxide (NO2), or NO2/GOX blends (Nytrox) to improve volumetric efficiency. Unfortunately, when these oxidizers are dropped-in to replace GOX, HPGHP systems have experienced ignition reliability and latency issues resulting from decomposition energy barriers found in both HTP and N2O.
Previously published studies have demonstrated catalytic-assist, using high-atomic-weight metals to decompose the incoming oxidizer and release free oxygen, as effective in increasing ignition reliability. In a typical configuration catalytic materials are supported by a substrate housed in an external pressure vessel placed in-line with the oxidizer flow-path. Unfortunately, in-line catbeds pose a series of technical issues. First, catbeds are heavy and add significantly to the spacecraft dry-mass without increasing propulsive efficiency. Second, in order to be effective, catalysts must be externally heated to high temperatures, often exceeding 300 oC. The required pre-heat energy has a significant impact on the total spacecraft energy budget. Finally, catbeds often self-consume at the high temperatures necessary for efficient decomposition action. There exists a universally limited operating lifetime for the expensive catalyst materials.
The presented research solves this problem. As described, external catalysts are replaced by an internal fuel-blend that mixes catalyst directly into the combustible material. The simple, inexpensive process works by cold-diffusion of 3D-printed ABS fuels with appropriate catalytic materials. The infused catalyst allows for near-instantaneous oxidizer decomposition, releasing gaseous oxygen that, when combined with spark energy, provides quick and reliable ignition. No system preheating is required, and the infused catalyst does not reduce the overall system performance. Design options and test results are presented for a 1-N HTP/ABS prototype thruster using potassium permanganate as the catalyst, and a 100-N Nytrox/ABS prototype using Ruthenium as the catalyst. Drop-in performance and reliability are demonstrated for both systems
University Nanosatellite Program: Assessment of Impacts From 25 Years of Education, Discussion of On-Going and Future Efforts
Get PDFThe University Nanosatellite Program (UNP) was founded in 1999 as the first government funded program to mentor university students in the design, integration, and operations of small satellites. This program provides a platform for university programs to develop DoD-relevant small satellite technologies while training the next generation in the principles and practices of systems engineering. UNP has assisted in the development of over 100 missions from over 53 universities across the country and has over 11,000 alumni.
This paper presents several aspects of UNP: a reflection on historical outcomes and impacts, educational impact on UNP participants, its current efforts, and changes to the program to better enable its mission.
First, a brief highlight of the program\u27s funding and programmatic history over the last 25 years is given. Then a discussion of the current efforts: Nanosatellite (a multi-phased competition cycle with six schools currently proceeding towards launch), Mission Concept (maturing a mission concept for universities over a summer), and Technical Insertion (creation of a specific mission for AFRL). This discussion will dive into student and faculty demographics, student outcomes and impacts, and program partnerships. Next, a discussion is included about potential changes to the program to better enable education. These changes may also enable faster mission maturation and guide more schools to the launch pad. Finally, ideas for the continuation of mentoring students in small satellite systems engineering are presented for both engaging with UNP and broader educational opportunities
An Autonomous Reinforcement Learning Framework for Fault Recovery and Mission Replanning on CubeSats
Get PDFOnboard system failures during CubeSat operation can have significant consequences for mission success. Limited resources during the development process can hamper the development and implementation of recovery systems, increasing the likelihood of mission failures. In response, this paper establishes a reusable autonomous framework for mission replanning in the event of an onboard system failure. Prior to launch, the framework ingests a standardized mission plan detailing mission objectives, mission priorities, and onboard capabilities and resources. Segmenting this information into a set of discrete tasks with completion dependencies, a reinforcement learning approach is used to select a schedule of tasks with the greatest priority while meeting resource limitations. This selection is scheduled into a new mission plan using a modified reinforcement learning approach. Testing this framework on a series of simulated satellite missions, it demonstrates moderate success in adapting multi-system failures, such as a variety of attitude control, power storage and generation, and computational faults