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At least 253 records · Page 14

Macular Preprocessing of Linear Acceleratory Stimuli: Implications for the Clinic

Three-dimensional reconstructions of innervation patterns in rat maculae were carried out using serial section images sent to a Silicon Graphics workstation from a transmission electron microscope. Contours were extracted from mosaicked sections, then registered and visualized using Biocomputation Center software. Purposes were to determine innervation patterns of type II cells and areas encompassed by vestibular afferent receptive fields. Terminals on type II cells typically are elongated and compartmentalized into parts varying in vesicular content; reciprocal and serial synapses are common. The terminals originate as processes of nearby calyces or from nerve fibers passing to calyces outside the immediate vicinity. Thus, receptive fields of the afferents overlap in unique ways. Multiple processes are frequent; from 4 to 6 afferents supply 12-16 terminals on a type II cell. Processes commonly communicate with two type II cells. The morphology indicates that extensive preprocessing of linear acceleratory stimuli occurs peripherally, as is true also of visual and olfactory systems. Clinically, this means that loss of individual nerve fibers may not be noticed behaviorally, due to redundancy (receptive field overlap). However, peripheral processing implies the presence of neuroactive agents whose loss can acutely or chronically alter normal peripheral function and cause balance disorders. (Platform presentation preferred - Theme 11)

Ross, M. D.↗

Using Coordinated, Multi-Agent Platforms for Dynamic Ocean Worlds Science

Planetary science missions have the opportunity to enhance science return through deployment of autonomous capabilities designed to dynamically respond to new information. Future outer solar system missions to ocean worlds in particular would benefit from this technology - intelligent science payloads (ISP) - because it would allow for a coordinated, near real-time response to ephemeral ‘events’ such as plumes, tectonism, surface implantation, volatile releases, thermal and magnetic anomalies, or radiation, as well as increasing the cadence and coverage of data collection. Prioritization and decision-making frameworks from ISP could be deployed at various scales - from analysis onboard a spacecraft with multiple instruments – to coordinated analyses among separate spacecraft in an e.g., distributed systems mission (DSM) composed of multiple SmallSats. Goddard’s Intelligent Science Payload team is developing an agile autonomous architecture for an icy ocean worlds DSM concept. Our goals are to coordinate data collection and onboard data analysis, and to make autonomous decisions for new data collection and analysis based on science priorities between multiple spacecraft with variable instrumentation and orbits. We use a range of data analysis tools to coordinate the DSM response, spanning from observations of data over a specified threshold to more computationally intensive machine learning algorithms (ML). ML algorithms here currently focus on determining the composition of an ocean world using mass spectrometry, and specifically methods for understanding ‘novelties’ and potential biosignatures. These algorithms could be used to quickly process and analyze onboard data that would be significantly delayed in downlink due to long communication delays for outer solar system missions in order to make dynamic science observations. Our ocean worlds case study ISP architecture is intended as an ‘agile’ and modular framework that could be used as a whole or as particular modules based on mission needs.

Distributed Systems↗

Life Cycle Cost Modeling of High-speed Commercial Aircraft - Final Report

SpaceWorks has concluded a 9-month research and development project aimed at addressing key questions in NASA’s effort to anticipate, understand, and ultimately support the emerging high-speed commercial flight market. The current project is a continuation of the Life Cycle Cost Modeling of High-Speed Commercial Aircraft1 , which is a follow-on to a 2021 study led by Deloitte and SpaceWorks entitled Commercial Hypersonic Transportation Market Study2 . Based in part on the recommendations of these prior studies, the objectives of this current effort were to expand the trade space to include Mach 1.5 aircraft and conduct additional trade studies. These included utilizing tech stops to extend serviceable range between city pairs, mixed aircraft fleets based on market size, flight scheduling to maximize value of the travel opportunity, and scenarios with multiple service operators. Additionally, SpaceWorks conducted new market surveys and research to update air passengers’ willingness-to-pay for highspeed flights given the changes in macroeconomic conditions since the start of the Commercial Hypersonic Transportation Market Study with Deloitte. Ultimately, the new data and capability to evaluate all the trade studies were implemented in a new simulation environment called MIDAS (Multi-market Integrated Dynamic Aerospace Simulation). This sophisticated tool, implemented using AnyLogic software, utilizes agent-based and discrete event simulation (DES) techniques to provide highly detailed analysis and assessment of the high-speed aircraft market problem.

high-speed↗

Solvated Electrons Have Multiple Personalities in Molten Salts

P-Crosscut: Solvated Electrons Have Multiple Personalities in Molten Salts [EFRC – MSEE] Alejandro Ramos-Ballesteros;1 Hung H. Nguyen;2 Kazuhiro Iwamatsu;3 Santanu Roy;4 Vyacheslav Bryantsev;4 Michael E. Woods;1 Ruchi Gakhar;1 Phillip Halstenberg;4 Bobby Layne;5 Jay A. LaVerne;6 Claudio J. Margulis:2* and James F. Wishart5* 1Idaho National Laboratory; 2The University of Iowa; 3Hunter College; 4Oak Ridge National Laboratory; 5Brookhaven National Laboratory; 6University of Notre Dame Abstract: The solvated (eS–) is a powerful reducing agent and one of the primary products of molten salt radiolysis. In these extreme high-temperature environments, the eS– can initiate cascades of redox processes that significantly alter the physical and chemical properties of a molten salt, posing challenges for molten salt reactor (MSR) performance and longevity. Consequently, mastering the fundamental behavior of the eS– could enable the design of specific molten salt mixtures with tailored Lewis acidities for controlling the speciation and chemical reactivity of the eS–, thereby mitigating its overall impact on MSR technologies. Here, we use time-resolved electron pulse radiolysis techniques for determining chemical kinetics and transient absorption spectra, combined with ab initio molecular dynamics simulations to explore the influence of multivalent metal cations on the fundamental speciation and distribution of eS– coordination environments.

38 - RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCL↗

AI Curation Methods for NASA Scientific Data

The NASA Open Science Data Repository (OSDR) serves as a central hub for sharing and accessing NASA's vast collection of scientific data, supporting researchers across diverse fields. To enhance the efficiency, accuracy, and accessibility of this data, we are leveraging advanced artificial intelligence (AI) techniques as part of the AI for Curation project. By integrating large language models (LLMs) into our data curation workflow, we aim to streamline the entire process—from data submission to user interaction. This initiative focuses on improving key areas, including data ingestion, curation, and user engagement with curated datasets, impacting multiple domains and a wide user base. First, we are developing tools that can automatically parse data in various formats, using LLMs to convert unstructured data into structured, standardized formats. This reduces the manual effort required for curation, allowing curators to focus on more critical scientific analyses. Additionally, AI and machine learning (ML) models are being implemented to automate data validation and verification, ensuring the highest standards of data quality and reliability. Finally, we are creating a conversational AI agent to interact with the curated scientific studies in OSDR, helping users easily navigate the repository and access relevant data. By enhancing data discoverability and accessibility, these advancements will foster new research opportunities and promote the principles of open science.

Walter Alvarado↗

Using APEX to Model Anticipated Human Error: Analysis of a GPS Navigational Aid

The interface development process can be dramatically improved by predicting design facilitated human error at an early stage in the design process. The approach we advocate is to SIMULATE the behavior of a human agent carrying out tasks with a well-specified user interface, ANALYZE the simulation for instances of human error, and then REFINE the interface or protocol to minimize predicted error. This approach, incorporated into the APEX modeling architecture, differs from past approaches to human simulation in Its emphasis on error rather than e.g. learning rate or speed of response. The APEX model consists of two major components: (1) a powerful action selection component capable of simulating behavior in complex, multiple-task environments; and (2) a resource architecture which constrains cognitive, perceptual, and motor capabilities to within empirically demonstrated limits. The model mimics human errors arising from interactions between limited human resources and elements of the computer interface whose design falls to anticipate those limits. We analyze the design of a hand-held Global Positioning System (GPS) device used for radical and navigational decisions in small yacht recalls. The analysis demonstrates how human system modeling can be an effective design aid, helping to accelerate the process of refining a product (or procedure).

VanSelst, Mark↗

Using Wind Driven Tumbleweed Rovers to Explore Martian Gully Features

Gully features have been observed on the slopes of numerous Martian crater walls, valleys, pits, and graben. Several mechanisms for gully formation have been proposed, including: liquid water aquifers (shallow and deep), melting ground ice, snow melt, CO2 aquifers, and dry debris flow. Remote sensing observations indicate that the most likely erosional agent is liquid water. Debate concerns the source of this water. Observations favor a liquid water aquifer as the primary candidate. The current strategy in the search for life on Mars is to "follow the water." A new vehicle known as a Tumbleweed rover may be able to conduct in-situ investigations in the gullies, which are currently inaccessible by conventional rovers. Deriving mobility through use of the surface winds on Mars, Tumbleweed rovers would be lightweight and relatively inexpensive thus allowing multiple rovers to be deployed in a single mission to survey areas for future exploration. NASA Langley Research Center (LaRC) is developing deployable structure Tumbleweed concepts. An extremely lightweight measurement acquisition system and sensors are proposed for the Tumbleweed rover that greatly increases the number of measurements performed while having negligible mass increase. The key to this method is the use of magnetic field response sensors designed as passive inductor-capacitor circuits that produce magnetic field responses whose attributes correspond to values of physical properties for which the sensors measure. The sensors do not need a physical connection to a power source or to data acquisition equipment resulting in additional weight reduction. Many of the sensors and interrogating antennae can be directly placed on the Tumbleweed using film deposition methods such as photolithography thus providing further weight reduction. Concepts are presented herein for methods to measure subsurface water, subsurface metals, planetary winds and environmental gases.

Antol, Jeffrey↗

Using Wind Driven Tumbleweed Rovers to Explore Martian Gully Features

Gully features have been observed on the slopes of numerous Martian crater walls, valleys, pits, and graben. Several mechanisms for gully formation have been proposed, including: liquid water aquifers (shallow and deep), melting ground ice, snow melt, CO2 aquifers, and dry debris flow. Remote sensing observations indicate that the most likely erosional agent is liquid water. Debate concerns the source of this water. Observations favor a liquid water aquifer as the primary candidate. The current strategy in the search for life on Mars is to "follow the water." A new vehicle known as a Tumbleweed rover may be able to conduct in-situ investigations in the gullies, which are currently inaccessible by conventional rovers. Deriving mobility through use of the surface winds on Mars, Tumbleweed rovers would be lightweight and relatively inexpensive thus allowing multiple rovers to be deployed in a single mission to survey areas for future exploration. NASA Langley Research Center (LaRC) is developing deployable structure Tumbleweed concepts. An extremely lightweight measurement acquisition system and sensors are proposed for the Tumbleweed rover that greatly increases the number of measurements performed while having negligible mass increase. The key to this method is the use of magnetic field response sensors designed as passive inductor-capacitor circuits that produce magnetic field responses whose attributes correspond to values of physical properties for which the sensors measure. The sensors do not need a physical connection to a power source or to data acquisition equipment resulting in additional weight reduction. Many of the sensors and interrogating antennae can be directly placed on the Tumbleweed using film deposition methods such as photolithography thus providing further weight reduction. Concepts are presented herein for methods to measure subsurface water, subsurface metals, planetary winds and environmental gases.

Antol, Jeffrey↗

Field Evaluations of Sampling, Interviewing, and Flight Tracking of NASA's Low Boom Flight Demonstrator Aircraft

The first year’s effort identified sampling and interviewing as the principal risks to assessment of prompt reactions to overflights producing low-amplitude sonic booms. It also 1) established the utility of geo-information system-based route planning for LBFD flight missions, 2) developed and demonstrated a prototype of a geographically-distributed, Internet-enabled instrumentation system capable of wide-area tracking of LBFD aircraft in near-real time. The latter system permits synchronizing the conduct of interviews in multiple overflown communities with arrival times of shock waves at interviewing sites; and of measuring, archiving, and processing their acoustic signatures. Means were also recommended for constructing representative, telephone-based samples of eligible respondents living in households within carpet boom corridors adjacent to LBFD flight tracks, and for conducting interviews with cross-sectional (independent) samples of such respondents about their prompt reactions to exposure to low-amplitude sonic booms. A detailed study design was prepared and accepted by NASA for a set of single-contact attempt telephone interviews with a nationally representative sample of households. The study design focused on testing automated and live agent interview completion rates obtainable without callbacks. A minimal (two monitoring station) version of the aircraft tracking system was built and installed near a civil airport in a successful demonstration of the system’s ability to detect and track aircraft movements. The field exercise also demonstrated the ability of the system to capture the acoustic emissions of departing aircraft, and to serve aircraft position and sound level information to remote, geographically-distributed analysts in near-real time. Upon approval of OMB and IRB of the detailed study plan, a stratified, nationally representative sample of landline and wireless telephone-subscribing households was constructed. A total of 12,734 telephone interview contact attempts of the sort required by a straightforward cross-sectional study design were then made. These contact attempts demonstrated the impracticality of conducting a time-critical, cross-sectional study of prompt community response to low-amplitude sonic booms by means of “independent” (single contact attempt per respondent for each LBFD flight mission) telephone samples of respondents. The observed interview completion rates for these single telephone contact attempts were so low (~ 1% to 3% for automated and live agent interviews, respectively) that: 1) the representativeness of collected opinions would be susceptible to intuitive challenge as inadequate, even absent conclusive evidence of non-representativeness. Refuting challenges to representativeness would have to demonstrate that the composition of the actual sample did not differ from that of the target population, a task that is tantamount to proving a negative; 2) the information required to refute allegations of non-representativeness would require a questionnaire considerably lengthier than that required simply to determine the prevalence of boom-induced startle and annoyance. Such a questionnaire would have to inquire about potentially sensitive and intrusive matters, including respondents’ age, gender, education, employment, home ownership, income, ethnicity, family size, and other demographic factors; and 3) unreasonable numbers of attempts would be required to re-contact households with unsuccessful initial contact attempts, given the limited time available for doing so. For example, if about 500 completed interviews were desired in a supersonically overflown community, approximately 50,000 automated interview attempts would have to be made within ten to fifteen minutes of each LBFD overflight. Such large numbers of contact attempts could well exceed the numbers of households available for interview in areas of similar boom exposure levels in some communities near LBFD flight tracks. Such large numbers of interviews could be cost-effectively undertaken only by means of automated (i.e., outgoing interactive voice response) interviewing, a data collection method ill-suited for complex and sensitive questionnaire items. The infeasibility of independent sampling for evaluating prompt responses to LBFD overflights in a cross-sectional study is due in large part to simple non-response: that is, potential respondents – particularly those contacted on wireless telephones – refusing to answer calls with unfamiliar caller IDs. It is also due in part, however, to 1) the lack of time to attempt to contact the same respondent more than once within a few minutes after the arrival of a shock wave at the respondent’s location; and 2) the need to place calls during weekday/daytime hours, when response rates are notably lower than during evenings and weekends. Despite the poor interview completion rates achieved under the above constraints, cross sectional assessments of delayed reactions to LBFD overflights could still be feasible, if multiple attempts could be made to contact respondents during evening and weekend time periods, over extended time periods. Detailed plans for a longitudinal (panel) sample were developed as an alternative to a cross sectional sample design.

Fidell, Sanford↗

Model-Drive Architecture for Agent-Based Systems

The Model Driven Architecture (MDA) approach uses a platform-independent model to define system functionality, or requirements, using some specification language. The requirements are then translated to a platform-specific model for implementation. An agent architecture based on the human cognitive model of planning, the Cognitive Agent Architecture (Cougaar) is selected for the implementation platform. The resulting Cougaar MDA prescribes certain kinds of models to be used, how those models may be prepared and the relationships of the different kinds of models. Using the existing Cougaar architecture, the level of application composition is elevated from individual components to domain level model specifications in order to generate software artifacts. The software artifacts generation is based on a metamodel. Each component maps to a UML structured component which is then converted into multiple artifacts: Cougaar/Java code, documentation, and test cases.

Gradanin, Denis↗

An Automated Approach to Map the History of Forest Disturbance from Insect Mortality and Harvest with Landsat Time-Series Data

Forests contain a majority of the aboveground carbon (C) found in ecosystems, and understanding biomass lost from disturbance is essential to improve our C-cycle knowledge. Our study region in the Wisconsin and Minnesota Laurentian Forest had a strong decline in Normalized Difference Vegetation Index (NDVI) from 1982 to 2007, observed with the National Ocean and Atmospheric Administration's (NOAA) series of Advanced Very High Resolution Radiometer (AVHRR). To understand the potential role of disturbances in the terrestrial C-cycle, we developed an algorithm to map forest disturbances from either harvest or insect outbreak for Landsat time-series stacks. We merged two image analysis approaches into one algorithm to monitor forest change that included: (1) multiple disturbance index thresholds to capture clear-cut harvest; and (2) a spectral trajectory-based image analysis with multiple confidence interval thresholds to map insect outbreak. We produced 20 maps and evaluated classification accuracy with air-photos and insect air-survey data to understand the performance of our algorithm. We achieved overall accuracies ranging from 65% to 75%, with an average accuracy of 72%. The producer's and user's accuracy ranged from a maximum of 32% to 70% for insect disturbance, 60% to 76% for insect mortality and 82% to 88% for harvested forest, which was the dominant disturbance agent. Forest disturbances accounted for 22% of total forested area (7349 km2). Our algorithm provides a basic approach to map disturbance history where large impacts to forest stands have occurred and highlights the limited spectral sensitivity of Landsat time-series to outbreaks of defoliating insects. We found that only harvest and insect mortality events can be mapped with adequate accuracy with a non-annual Landsat time-series. This limited our land cover understanding of NDVI decline drivers. We demonstrate that to capture more subtle disturbances with spectral trajectories, future observations must be temporally dense to distinguish between type and frequency in heterogeneous landscapes.

Forest↗

Environmental associations of Ophidiomyces ophidiicola , the causative agent of ophidiomycosis in snakes

Emerging pathogenic fungi have become a topic of conservation concern due to declines observed in several host taxa. One emerging fungal pathogen, Ophidiomyces ophidiicola, is well documented as the causative agent of ophidiomycosis, otherwise known as snake fungal disease (SFD). O. ophidiicola has been found to cause disease in a variety of snake species across the United States, including the eastern massasauga (Sistrurus catenatus), a federally threatened rattlesnake species. Most work to date has involved detecting O. ophidiicola for diagnosis of infection through direct sampling of snakes, and attempts to detect O. ophidiicola in the abiotic environment to better understand its distribution, seasonality, and habitat associations are lacking. We collected topsoil and groundwater samples from four macrohabitat types across multiple seasons in northern Michigan at a site where Ophidiomyces infection has been confirmed in eastern massasauga. Using a quantitative PCR (qPCR) assay developed for O. ophidiicola, we detected Ophidiomyces DNA in topsoil but observed minimal to no detection in groundwater samples. Detection frequency did not differ between habitats, but samples grouped seasonally showed higher detection during mid-summer. We found no relationships of detection with hypothesized environmental correlates such as soil pH, temperature, or moisture content. Furthermore, the distribution of Ophidiomyces positive samples across the site was not linked to estimated space use of massasaugas. Our data suggests that season has some effect on the presence of Ophidiomyces. Differences in presence between habitats may exist but are likely more dependent on the time of sampling and currently uninvestigated soil or biotic parameters. These findings build on our understanding of Ophidiomyces ecology and epidemiology to help inform where and when snakes may be exposed to the fungus in the environment.

59 BASIC BIOLOGICAL SCIENCES↗

Controlling optical-cavity locking using reinforcement learning

Abstract This study applies an effective methodology based on Reinforcement Learning to a control system. Using the Pound–Drever–Hall locking scheme, we match the wavelength of a controlled laser to the length of a Fabry-Pérot cavity such that the cavity length is an exact integer multiple of the laser wavelength. Typically, long-term drift of the cavity length and laser wavelength exceeds the dynamic range of this control if only the laser’s piezoelectric transducer is actuated, so the same error signal also controls the temperature of the laser crystal. In this work, we instead implement this feedback control grounded on Q-Learning. Our system learns in real-time, eschewing reliance on historical data, and exhibits adaptability to system variations post-training. This adaptive quality ensures continuous updates to the learning agent. This innovative approach maintains lock for eight days on average.

47 OTHER INSTRUMENTATION↗

Cross-Linking Studies of Lysozyme Nucleation

Tetragonal chicken egg white crystals consist of 4(sub 3) helices running in alternating directions, the helix rows having a two fold symmetry with each other. The unit cell consists of one complete tetrameric turn from each of two adjacent helices (an octamer). PBC analysis indicates that the helix intermolecular bonds are the strongest in the crystal, therefore likely formed first. AFM analysis of the (110) surface shows only complete helices, no half steps or bisected helices being found, while AFM line scans to measure the growth step increments show that they are multiples of the 4(sub 3) helix tetramer dimensions. This supports our thesis that the growth units are in fact multiples of the four molecule 4(sub 3) helix unit, the "average" growth unit size for the (110) face being an octamer (two turns about the helix) and the (101) growth unit averaging about the size of a hexamer. In an effort to better understand the species involved in the crystal nucleation and growth process, we have initiated an experimental program to study the species formed in solution compared to what is found in the crystal through covalent cross-linking studies. These experiments use the heterobifunctional cross-linking agent aminoethyl-4-azidonitroanaline (AEANA). An aliphatic amine at one end is covalently attached to the protein by a carbodiimide-mediated reaction, and a photo reactive group at the other can be used to initiate crosslinking. Modifications to the parent structure can be used to alter the distance between the two reactive groups and thus the cross-linking agents "reach". In practice, the cross-linking agent is first coupled to the asp101 side chain through the amine group. Asp101 lies within the active site cleft, and previous work with fluorescent probes had shown that derivatives at this site still crystallize in the tetragonal space group. This was also found to be the case with the AEANA derivative, which gave red tetragonal crystals. The protein now has a reactive group that can be photoactivated at a specific point in the nucleation or crystal growth process to "capture" protein molecules bound within reach of the crosslinking agent. If those bound protein molecules have a defined geometric relationship with the capturing molecule, such as would be found in a crystal, then the photoreacted cross-linking site should be consistent. Random protein interactions, typical of an amorphous precipitate or interaction, would show a random cross-linking reaction. The results of these and other experiments will be presented.

Forsythe, Elizabeth↗

X-Ray Amorphous Sulfur-Bearing Phases in Sedimentary Rocks of Gale Crater, Mars

The Curiosity rover in Gale crater is investigating a mineral transition observed from orbit—an older “clay unit” to a younger “sulfate unit”—hypothesized to reflect the aridification of Mars' climate. Below this transition, the rover detected crystalline Ca-sulfates with minor Fe-sulfates but also found that some fraction of a rock's bulk SO 3 is often in the poorly constrained X-ray amorphous component. Here, we characterize the abundances and compositions of the X-ray amorphous sulfur-bearing phases in 19 drilled samples using a mass balance approach, and in a subset of 5 samples using evolved SO 2 gas measured using the SAM instrument. We find that ∼20–90 wt% of a sample's bulk SO 3 is in the X-ray amorphous state and that X-ray amorphous sulfur-bearing phase compositions are consistent with mixtures of Mg-S, Fe-S, and possibly Ca-S phases, likely sulfates or sulfites. These phases reside in the bedrock, perhaps as cementing agents deposited with detrital sediments or during early diagenesis, and in diagenetic alteration halos deposited after lithification during late diagenesis. The likely presence of highly soluble Mg-sulfates in the rocks suggests negligible fluid flow through the bedrock post-Mg-sulfate deposition. The X-ray amorphous sulfur-bearing phases probably became amorphous through dehydration in the current Martian atmosphere or inside the CheMin instrument. X-ray amorphous sulfur-bearing materials likely contribute to orbital spectral detections of sulfates, and so our results help form multiple hypotheses to be tested in the sulfate unit and are important for understanding the evolution of the Martian surface environment at Gale crater.

R. J. Smith↗

Optical Navigation for Autonomous Approach of Small Unknown Bodies

State of the practice in navigation around small celestial bodies heavily relies on ground sup- port and human skill, in particular, for perception-based operations such as optical navigation and mapping. This leads to longer duration and more complex mission operations and sub- sequently higher cost. Furthermore, it imposes limitations for certain missions such as fast fly-bys or multi-agent operations. In this work, we present an autonomous navigation strat- egy suitable for approaching small unexplored bodies. During the approach, we estimate the body’s physical properties as well as the spacecraft’s relative trajectory and associated un- certainties. The autonomous navigation strategy, which is solely based on optical measure- ments, begins as soon as the body becomes resolved in the navigation camera and terminates at the start of proximity operations, when the spacecraft makes its first trajectory correction to stay in the vicinity of the body. Our strategy uses multiple image-processing algorithms: light-curve analysis for estimating the target body’s rotation rate, Shape-from-Silhouette for reconstructing the 3D shape and estimating its rotation pole, and feature tracking tailored to Small-Body images for estimating relative navigation parameters. We used the Mission Analysis, Operations, and Navigation Toolkit Environment (MONTE) developed by the Jet Propulsion Laboratory to evaluate the feasibility of this multi-phase navigation strategy using simulated images of an approach trajectory. We used the Rosetta mission data to generate photorealistic images to characterise the performance of this approach. This work is based on the assumptions that the spacecraft attitude is known, the body is a principal-axis rotator, a-priori estimates of ephemerides and scale are available, and the body is observed from a zero sun phase only during initial approach. Preliminary results show orbit determination performance that is on par with the human navigation from the Rosetta mission; albeit with a 1% bias in spacecraft-target radial distance estimate. The bias error is likely due to the robustness and accuracy of the visual tracking under dynamic lighting conditions and per- spective changes, which decrease accuracy.

Villa, Jacopo↗

OTF Proof of Concept: CCSDS Mission Operations Alert Services

Conclusions: Use of multiple vendor frameworks within a component creates thread lockups and fragility conflicts over the control of the main thread. Avoid closed vendor messaging frameworks. The MAL layer does isolate the data elements from the messaging framework but application work dispatch is heavily dominated by the framework chosen. API Language is a major factor in implementation. Message APIs with timeouts seem unavoidable in some environments (GUI). Language environment needs to support callbacks (or threads) from the messaging framework to deal with pub/sub management messages and status. Statusing of application communications demand a local broker agent per physical system or else the use of the AMSstyle registrar heartbeat.

Reynolds, Walt↗

Optimization and stabilization of Fermilab Booster using hybrid Bayesian/RL framework

PIPII project will raise Fermilab Booster intensity and ramp rate. Beam losses will limit average power and are hard to simulate. Presently, Booster uses operator-guided empirical tuning. This task is challenging due to high dimensionality, multiple objectives, critical safety constraints, and drifts. We developed a synergistic suite of Bayesian optimization (BO) and reinforcement learning (RL) tools to optimize and stabilize beam losses. First, active learning was used to build a rough model. Data was collected parasitically using two novel safety constraint types – nonlinear input space restrictions (based on optics model), and uncertainty constraints (to stop bad steps/beam aborts). We then applied online multi-objective BO with scalarized objectives and fitting to improve/rebalance losses, increasing safety margins by 25%. Using BO model as a safety veto, we tried several on/off-policy RL agents for long term stabilization; SAC had best performance. We found that adding contextual (state) information further improved performance, eventually integrating key knobs like linac phase and temperature into the parameter space. Long term testing is ongoing to enable operational use.

Kuklev, Nikita [Fermilab]↗