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Soil Additives and Alternative Crops for Drought Defense in the Intermountain West
Get PDFThe Western U.S. looks for water optimization and conservation as agriculture is the largest water diverter, and resources are pressured by urban growth, winter snowpack instability, and drought persistence. Agricultural producers have several potential options to optimize water use with different investments associated with them. Options with varying levels of risks and known management practices include alternative crops, soil wetting agents, and crop biologicals. An alternative crop that grew incredibly fast in popularity was industrial hemp (Cannabis sativa) despite limited agronomic knowledge for best management practices. Field trials occurred (2020-2022) near Logan, UT to test a total of 17 common regionally available hemp cultivars. The cultivars producing the best yields and quality included Abacus Improved, Trump, and Royal South. However, high performance variability of cultivars indicated that more testing may be required as stability in cultivar stock occurs. A two-year (2020-21) hemp trial examined combinations of three hemp cultivars, four sprinkler irrigation sprinkler technologies, and four irrigation rates. The three hemp cultivars responded similarly to irrigation management, although there was high plant variability. This research suggested that floral hemp could be irrigated less than other common region crops to maintain yield in the region and potentially control THC concentrations. An online grower survey gathered responses from 85 licensed Utah hemp growers to understand practices implemented in the beginning years, representing 72% of Utah counties and covering outdoor and indoor growing conditions. Results indicated opportunities for improved fertilizer, irrigation, and pest best management practices for hemp to refine product quality, production costs, and revenues. Similar studies were conducted to test soil wetting agents and bio-stimulants. Both product types were tested in silage corn (Zea mays), alfalfa (Medicago sativa), and small grain forage (Triticum aestivum, Hordeum vulgare, and Secale cereale × Triticum aestivum). Trials were conducted from 2019 to 2023 for wetting agents, and 2022 to 2023 for biologicals at Logan, Vernal, and Cedar City, Utah. Yield and forage quality parameters were rarely enhanced by product application. Based on these results, tested soil wetting agents nor biologicals should not be used as drought protectors in soils with limited soil restriction
Untangling Safe-Mode Anomalies on the CUTE CubeSat
Get PDFThe Colorado Ultraviolet Transit Experiment (CUTE) is NASA\u27s first 6U NASA Astrophysics CubeSat built by the Laboratory for Atmospheric and Space Physics (LASP). Its primary purpose is to observe the evolving atmospheres of short-period exoplanets in the near-ultraviolet. It was launched in September 2021 into a ~560 km, polar orbit with a 98.5° inclination. The spacecraft bus, featuring avionics and an attitude determination and control system (ADCS) with a single star tracker, was supplied by Blue Canyon Technologies (BCT). Since its launch, CUTE has experienced an unusually high frequency of ADCS-driven safe mode events, occurring up to three times per week. An investigation into the issue revealed the frequent safe mode events to be due to a timing issue of the Inertial Measurement Unit (IMU) information packets before being sent to the Guidance, Navigation and Control system (GNC). This issue is described as a glitch due to the sudden jump discontinuity in certain spacecraft telemetry data following an IMU timing issue. Telemetry analysis revealed significant discrepancies between commanded and reported attitude quaternions, casting doubt on the spacecraft\u27s reported attitude and telemetry values during these glitch events. By conducting a thorough analysis of Sun sensor photodiode counts, battery cycles, spacecraft body rate, and magnetic field vectors, we concluded that the spacecraft\u27s reported quaternions did not accurately reflect its actual orientation following the glitch events. The team utilized basic attitude determination methods, such as integrating the spacecraft\u27s body rate, to further approximate its attitude around the glitches. This calculated attitude revealed that, at times, the glitch was causing the spacecraft\u27s telescope to partially orient towards the Sun, likely leading to the degradation of the primary science instrument over time. This paper explores the pivotal role of ground-truth telemetry points in conjunction with simple attitude verification methods in identifying and understanding anomalies in satellite attitude and on-orbit behavior. This work is likely to assist other teams facing similar challenges and highlights the effectiveness of simple yet powerful spacecraft attitude determination methods
VERTECS: 6U CubeSat Mission to Study Star-Formation History by Observation of Visible Extragalactic Background Light
Get PDFWe describe an astronomical 6U CubeSat mission VERTECS (Visible Extragalactic background RadiaTion Exploration by CubeSat). The scientific purpose of VERTECS is to reveal star-formation history of the universe by observation of the extragalactic background light (EBL) in visible wavelengths. Earlier observations by sounding rockets and infrared astronomical satellites have shown that the near-infrared EBL is several times brighter than the integrated light of known galaxies. As candidates for the excess light, first-generation stars in the early universe or low-redshift intra-halo light have been proposed, but it has not been concluded. Since these objects are expected to show different emission spectra in visible wavelengths, precise visible observation is important to reveal the origin of excess light. Since detection sensitivity of the EBL is determined by the product of telescope aperture and field of view, a small wide-field telescope system enables the EBL observation with high sensitivity. In VERTECS mission, we develop a 6U CubeSat equipped with a 3U size telescope optimized for observation of visible EBL. The telescope is composed of lens optics and a CMOS sensor of 3k times 3k array format, which is designed to observe the sky in four photometric bands in 400-800nm. The satellite bus is composed of on-board computer (OBC), electric power system (EPS), communication (COM), attitude determination and control system (ACDS), and thermal structure. Design of OBC and EPS is based on heritage of CubeSats developed at Kyushu Institute of Technology, but deployable solar array wings is added to EPS to supply sufficient power to the VERTECS subsystems. In COM system, S-band is used for command uplink and X-band is used for high-speed downlink of large-size images captured by the telescope. Since the EBL measurement need discrimination of the background light from discrete foreground stars, VERTECS requires 10 arcseconds pointing stability (1 sigma) over 1 minute exposure. In 2022, VERTECS was selected for JAXA-Small Satellite Rush Program (JAXA-SMASH Program), a new program that encourages universities, private companies and JAXA to collaborate to realize small satellite missions utilizing commercial small launch opportunities, and to diversify transportation services in Japan. We have been working on functionality and interface teast using Bread Board Model (BBM), and enviroonmental tests by using the satellite structure thermal model. Launch of the satellite is planned in FY2025. We aim at developing the satellite and obtaining scientific results much more quickly than recent large astronomical-satellite missions
University Class Open Ground Station (UniClOGS)
Get PDFMost educational CubeSat projects have the same dilemma: not enough money to buy a commercially available ground station, and not enough internal experience and capabilities to build a reliable and inexpensive ground station in-house. We present a middle road to the commercial off-the-shelf (COTS) vs DIY conundrum for ground stations: the University Class Open Ground Station (UniCIOGS). UniCIOGS is an open-source satellite communications ground station meant to be customized and built by university and other small satellite operators around the world. UniCIOGS is primarily designed for amateur radio satellites; amateur licensing allows for groups to share transmit-capable stations. Even international amateur radio groups can share UniCIOGS stations between countries that have amateur radio reciprocal operating agreements. For non-amateur radio satellites, a local UniCIOGS installation can be used by local satellite operators, but remote sharing becomes problematic. UniCIOGS is inspired by the extremely successful Satellite Networked Open Ground Station (SatNOGS), a global network of receive-only open-source ground stations hosted by the Libre Space organization. Because SatNOGS is receive-only, SatNOGS installations can be operated by any non-licensed individual or organization. UniCIOGS is meant to allow amateur-radio licensed operators to have transmit capabilities in parallel with the SatNOGS receive network.
UniCIOGS installations are designed to handle UHF, L, S, and X band links. They are based on a customizable selection of COTS hardware. Transceivers are based on open source software defined radios (SDR) with COTS preamps, power amps, filters, and RF switching paths. Antennas, rotators, and structures are also a selectable series of COTS parts that can be chosen based on installation location and pointing accuracy. The design scales to a mission\u27s RF and orbit requirements without major rework, including a minimal case for hardware-in-the-loop testing on a flatsat integration test platform. Prices for a complete station typically range from 25,000 for a sophisticated one.
UniCIOGS software is based on comprehensive Python scripts for station control, automation, and data transfer. GNU Radio is used for SDR control, allowing for extremely flexible radio protocol implementations. Satellite commands can be originated and responses stored in existing telecommand software such as Yamcs (Yet Another Mission Control System). Finally, all computers are based on simple, low-power, networked Linux computers that allow for remotely operated stations.
Currently, three UniCIOGS installations have been designed, built, and are being operated by students at Portland State University in Portland, OR. Other universities are building their own stations based on our publicly-available CAD and documentation, including University College London, Cal Poly Pomona\u27s Bronco Space, and UCLA\u27s Bruin Space
Generalized Attitude Estimation for Spacecraft
Get PDFAttitude state estimation for spacecraft often requires writing an integrator or filter from scratch, with choices depending on the expected sensors, spacecraft and mission properties, and computational resources available. We create a customizable object-oriented satellite dynamics model with a variety of sensors, actuators, and disturbances that can be easily applied to any small spacecraft. Relevant disturbances can be modeled (or ignored), sensor and actuator biases are tracked, and outside effects like eclipse on sun sensors are included. In this work, we demonstrate the use of a new model to create a dynamics-aware unscented Kalman filter (UKF) that, in simulation, outperforms current and previous estimators, even for large satellites and achieves sub-degree accuracy for a small satellite. For example, the mass properties of a satellite, the actuator and sensor properties, and relevant disturbances can be input, and the UKF with relevant dynamics, update, and propagation steps will be created. This allows for rapid testing of various estimation and control paradigms, and the quick development of an attitude determination system (ADS)
NASA PRISM\u27s Lunar Vertex Mission – Lessons Learned in Establishing a New Low-Cost Science Mission Paradigm
Get PDFLunar Vertex (LVx), a lander-rover science investigation of Reiner Gamma, was selected as NASA\u27s first PRISM (Payloads and Research Investigations on the Surface of the Moon) mission in June 2021. The PRISM program is under NASA\u27s Planetary Missions Program Office (PMPO). To facilitate a quick delivery at low cost, NASA is managing PRISM missions to the requirements for research and technology projects as documented in NASA Procedural Requirements document NPR 7120.8. It is JHU/APL\u27s first science mission developed under the NPR 7120.8 requirements. NASA and JHU/APL worked together to accept a higher risk posture, to allow for less stringent requirements, significantly reduced documentation, and reduced oversight and review than required for flight projects managed to NASA Procedural Requirements document NPR 7120.5. This program structure facilitates use of commercial products, providing a pathway for new suppliers to participate in NASA scientific investigations. Lunar Vertex (LVx) is a pathfinder to establishing a new lost-cost science mission paradigm and has been a learning experience for everyone involved. Lessons learned have been identified and recommendations are provided
Automating Maneuvers: Considerations for Collision Avoidance
Get PDFAs more space operators implement large constellations of spacecraft, automating orbit maintenance maneuvers becomes a key feature of their operations concept to ensure that the workload is manageable. However, the practice of performing a maneuver without sharing the plan with other nearby spacecraft causes a risk that two spacecraft will collide, not only destroying the spacecraft involved, but creating debris that will affect all other spacecraft using that orbit regime. In order to share the maneuver plan, a predicted ephemeris file containing the maneuver must be sent to a central authority to screen against predicted trajectories of all other on-orbit objects to determine where and when close approaches will occur that may need to be mitigated. Currently the screening authority used by US operators is the 19th Space Defense Squadron; screenings are performed once every 8 hours, meaning that spacecraft using automated maneuvering need to allow 16 hours to share their maneuver plan via the screening process in advance of maneuver execution in case one screening is missed and the next needs to be used.
In an effort to speed up the screening process to benefit spacecraft using automated maneuvering, a prototype system for performing near-real-time screenings has been developed in support of the NASA Starling mission, a constellation of four cubesats that fly at the same altitude as the SpaceX Starlink constellation. Both of these constellations perform automated maneuvering, so without screening the planned maneuvers before execution, the two constellations would risk a collision. This paper describes the traditional conjunction assessment (CA) process, the prototype real-time CA screening capability, plans for the experiment to test the prototype, and next steps
Hera Cubesats Trajectory Design and ConOps for Didymos Binary Asteroid Characterization
Get PDFThe Asteroid Impact Deflection Assessment (AIDA) mission, a collaborative effort for Planetary Defense, involves the DART and Hera spacecrafts targeting the Didymos-Dimorphos binary asteroid system. Their objectives include assessing asteroid deflection, conducting close observations, and demonstrating future mission technologies. DART, launched by NASA, impacted Dimorphos in September 2022. While Hera, an ESA spacecraft, carrying Juventas and Milani 6U-XL CubeSats, will be launch in October 2024 to reach the binary asteroid system after a two-year Cruise. Hera will arrive in December 2026 in order to characterize afterwards the result of the DART impact in terms of reshaping and deflection of Dimorphos. The French Space Agency (CNES) contributes to Hera’s mission through CubeSats preliminary trajectory design and close proximity operations for flight dynamics and payloads programming. From the mothercraft ejection to the realization of the scientific objectives of the different payloads (imager, radar, gravimeter, radio-science experiment) to landing, the proximity operations will be held in 2027 within the C-FDSOC (Cubesats Flight Dynamics and Science Operation Center, France) in support of the CMOC (Cubesat Mission Operation Center, Belgium) with direct interface with the HMOC (Hera Mission Operation Center, Germany) as all uplinks and downlinks transit through the Hera mothership. Taking into account the various constraints for each phase implies specific trajectories design with dedicated maneuver strategies and payloads acquisitions sequences through an adapted Concept of Operations shared with Hera ground segment European stakeholders and Payloads teams. This paper will therefore present the different types of trajectories and the preliminary ConOps and necessary ground segment automation elaborated to fulfill mission programming and flight dynamics objectives for the two Hera CubeSats, Milani and Juventas
Big Red Sat-1: Mission Overview and Future Opportunities for Perovskites in Low Earth Orbit
Get PDFPerovskite solar cells are an emerging technology that holds the promise of reducing the size and weight of solar panels on satellites. While many research laboratories have produced perovskite solar cells and characterized their performance in laboratory conditions, few have endeavored to launch them into space. The Big Red Sat-1 (BRS-1) is one such satellite, designed to incorporate three different perovskite solar cell architectures along with custom curve tracing instrumentation for launch into low earth orbit through NASA\u27s CubeSat Launch Initiative. The curve tracer is realized using a precision resistor ladder with high quality current and voltage measurements. Perovskite solar cell samples were fabricated by the National Renewable Energy Laboratory and characterized in their facilities before shipment. These cells were recharacterized using flight hardware before integration into the Nanoracks launcher. In addition to the eighteen perovskite solar cell pixels, a gallium arsenide (GaAs) solar cell was included to trigger measurements when the BRS-1 is pointing at the sun. During nominal operations, the BRS-1 will continuously take J-V curves while the GaAs solar cell is illuminated and will be in a low power state otherwise. Future missions should include a sun vector sensor for precise solar flux measurements, active curve tracing for dark current measurements, and explore alternative perovskite solar cell architectures including tandem cells. All designs for BRS-1 have been made open source to benefit other student-led missions. BRS-1 is currently in-orbit and transmitting measurement data
Dynamics of Climate and Tectonics on Surface Processes and Their Sedimentary Archives in the Colorado Plateau and Basin and Range, USA and the Calabrian Forearc, Sicily
Get PDFLandscapes change over time in response to movements of the Earth’s crust and the effects of climate. This dissertation examines how these factors shape different landscapes, focusing on erosion of river canyons in elevated plateaus, how the transport history in quartz sand may be encoded in its properties, and how a paleo-delta has formed in response to sea-level change and fault displacement. I use dating techniques, field methods, and topographic analyses to offer insight into erosional patterns and rates in different landscapes. Rivers can take a long time to adjust to changes in boundary conditions, even after those changes have ceased. I studied the Colorado River incision history in the tectonically stable central Colorado Plateau of Utah, to understand the timing, spatial variability, and controls on canyon carving. The incision history and topography of the region show remarkable variability in erosion across the region and through time, with significant rapid incision of ~250 meters in the last 350,000 years. Results suggest this rapid erosion is a signal derived from baselevel fall by the Colorado River in the Grand Canyon region 5 million years ago. This study shows that even without major tectonic or climate change, landscapes can still maintain complex erosion patterns. Optically stimulated luminescence sensitivity is a new technique used to study Earth’s surface processes. However, the geologic processes that induce a luminescence phenomenon in quartz are still unknown. I investigate the geologic controls on the luminescence sensitivity of quartz sand using rocks and modern and paleo- river sediments in a small mountainous catchment in northern Utah, USA. The results indicate that the luminescence phenomena in quartz is enhanced with the time spent at the Earth’s surface as the sand grain weathers, erodes, and is transported along hillslopes to river systems. The Pagliara fan-delta in northeastern Sicily provides a unique opportunity to study how coastal sediments stack through time in response to climate and sea-level change and tectonic history. Dating of the delta using luminescence techniques, reveals that the delta formed 300 – 220 thousand years ago when accommodation space was generated by sea-level fall and subsidence from fault movement. After this time, river and shore processes began to excavate the delta, indicating a shift from sediment accumulation in the delta to tectonic uplift. Despite the change in tectonic stress revealed in the delta stratigraphy, the uplift and erosion rates of the region have remained relatively constant over the past 300,000 years