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All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Autonomous Control for Arbitrary Thruster Configurations and Mass Properties in Special Euclidean Group SE(3)

Most current methods for determining maneuvers and thrust firing sequences depend on explicit and predetermined commands generated by a combination of on-board systems and ground-based human-in-the-loop methods. For spacecraft and space structures with changing mass properties and thruster configurations, such as the Deep Space Gateway as it changes configurations throughout its lifetime, determining these commands can be time-consuming and computationally intensive. However, recent work within the Lie group SE(3) has offered ways of autonomously determining the location, power, precision, and capabilities of thrusters in any arbitrary position. Furthermore, a method for determining thruster firing sequences based on an arbitrary control input (both translational and rotational in a coupled, 6-element vector) and arbitrary thruster configurations has also recently been developed. When combining these methods, any spacecraft with any mass properties and thruster configurations can be understood in terms of controllability limits and thruster firing sequences can be generated quickly and with low computational load, thus extending the autonomous capabilities of deep space missions. In this work, this method is presented and explored in terms of convergence time to the desired pose. The capabilities of this method are also examined in the case of the Deep Space Gateway both in fully controllable configurations and uncontrollable configurations.

SE(3)↗
NASA NTRSDate not supplied

Medical Risk Estimates and Clinical Capability Needs for A Long Duration Artemis Mission

BACKGROUND Human exploration spaceflight missions to the Moon and Mars present unprecedented challenges for in-mission medical care. Compared with the ISS, the greater distance from Earth will mean increased mission durations, communication delays, limited to no resupply opportunities, and significant limitations on the evacuation of ill or injured crew. Spacecraft mass, volume, and power will be curtailed while higher demands will be placed on the crew’s knowledge, skills, and abilities. In this higher risk environment, it is important to: a) quantitatively estimate human system risk attributable to medical conditions, a process known as Probabilistic Risk Analysis, and b) use these estimates to inform medical system design. IMPACT (Informing Mission Planning via Analysis of Complex Tradespaces) is a PRA and medical trade space analysis tool developed by NASA to advance exploration mission medical system design. IMPACT v1.0 improves upon and will soon replace NASA’s existing tool, the Integrated Medical Model, with: a novel evidence base baselined to exploration environments; an expanded list of 119 medical conditions; a significant increase in the number of medical resources that can be utilized and in the flexibility of their use; and the modelling of time lost performing mission-specific tasks due to medical conditions. DISCUSSION: This abstract will present IMPACT estimates of medical system risk and clinical capability needs for an extended duration Artemis mission of approximately 9 months, with phases including outbound transit, 3 months on the Lunar Gateway space station, 3 months on the Lunar surface with EVAs, 3 months on Gateway (simulating the return phase of a Mars mission), and transit back to Earth. Medical system risk estimates include loss of crew life (LOCL), consideration of medical evacuation (known as return to definitive care – RTDC), and an estimate of crew time lost due to medical conditions (Task Time Lost – TTL). The presentation will also describe the medical conditions that are the greatest drivers of risk as well as the clinical capabilities and resources that have the largest effect on risk.

W Thompson↗
NASA NTRSDate not supplied

Future Homes in Space: Development of Concepts for Exploration Space Habitats

NASA’s Artemis campaign seeks to return humans to the moon and establish a sustained presence on the lunar surface. This session will emphasize how habitation capabilities on the moon and in cislunar space can potentially contribute to the sustainability objectives of Artemis. Habitable elements represent opportunities to enable longer duration stays, increase the number of crew members present, enhance science and utilization activities, drive technology development for future Mars exploration, perform analog missions, and fuel economic opportunities for US industry. Panelists include Paul Kessler (NASA Marshall Space Flight Center, deputy lead for lunar surface habitation); Andrew Choate (NASA Marshall Space Flight Center, Mars habitation lead); Krystofer Dudzinski (NASA Marshall Space Flight Center, a space architect within the MSFC Advanced Concepts Office); and Larry Toups (retired from NASA Johnson Space Center, currently an adjunct professor at University of Houston in space architecture). The panel is moderated by Tracie Prater (NASA Marshall Space Flight Center, Habitation Systems Development Office). The panel will begin with an overview of the history of habitation concepts and an academic perspective on general considerations in space habitat design (Larry Toups). Paul Kessler and Andrew Choate will introduce NASA’s principle of “architecting from the right” to help define objectives for Artemis missions, needs/characteristics, use cases, and functions (as published in the agency’s Architecture Definition Document) and provide perspective on how this principle informs habitation concept development work. NASA panelists will discuss key engineering challenges identified for developing, deploying, and operating habitable assets on the lunar surface and/or in deep space. These may include dust mitigation, outfitting of inflatable softgoods (for concepts which may use softgoods as a primary structural material), survival in lunar darkness, human health and performance considerations, maintenance/repair/sparing, and autonomy. These identified challenges represent risks for habitation systems development and relate closely to capability gaps identified by the agency. While the work of NASA Marshall Space Flight Center’s habitation development office is primarily focused on habitats which are launched from earth pre-integrated (referred to as Class I in the framework previously developed by NASA space architects Kennedy/Cohen) or launched from earth and deployed at the point of use (Class II), there is also extensive work in NASA, academia, and companies on constructed habitats, which would be built on a planetary surface using indigenous resources (Class III habitats). Panelist Krystopher Dudzinski will discuss potential evolutionary pathways from Class I and Class II habitats to Class III habitats, unique and common architectural challenges within each habitat class, and key gaps in implementing Class III habitats from an architectural perspective. NASA panelists and the moderator will also provide an overview of partnership opportunities and avenues for further engagement to advance habitation systems for the SpaceCom audience. NASA is currently developing notional concepts for a lunar surface habitat and Mars transit habitat, which will be discussed during this panel session and used as examples. These concepts represent options for habitation system design and are a point of departure. They do not represent a final plan or formal recommendation on the part of the agency. Based on the most recent analysis cycle, NASA’s lunar surface habitat (SH) concept nominally supports two crew members for 30 days, with the capacity to support four crew during a surge period where crew will swap between the SH and another surface asset, such as a pressurized rover. This example design has a metallic airlock for ingress/egress and the upper portion is an inflatable material system which serves as the habitation module. The notional interior of the habitat is a three-deck layout/configuration which supports all crew mission functions, including exercise, stowage, extravehicular activity (EVA), sleep, hygiene waste collection, maintenance and repair, and meal preparation. Under analysis assumptions for habitation, the Mars Transit Habitat (TH) concept would support four crew on an up to 1,200 day Mars mission. One option for the concept is to initially dock Transit Habitat at Gateway, where it can be used to increase the duration of crew stays in cislunar space and perform shakedown and analog missions prior to a Mars departure. One challenge in longer duration missions which involve both surface exploration and transit is understanding crew adaptation when transitioning between partial gravity and microgravity environments. TH at Gateway offers an opportunity to study this transition and in doing so reduce risks associated with future Mars exploration. Like lunar SH, the most recent analysis cycle concept of a Mars TH is a hybrid structure design, with a metallic section supporting EVAs, axial/radial docking, and Safe Haven capabilities, and an inflatable softgoods structure for the primary habitation function. Interior layouts to optimize crew usability and livability are currently under trade. The panel will include presentation material, but also seeks to engage the audience in a highly interactive conversation regarding the potential role for habitation in future exploration initiatives. Potential topics for discussion include the influence of the crew experience on habitation systems design and livability/usability considerations, the benefits of space habitation development in terrestrial applications, and challenges and opportunities in “feeding forward” lunar surface habitation systems development to Mars exploration.

space habitats↗
NASA NTRS2024

Quantifying Risk to Improve Medical System Design for Long Duration Artemis Missions: A Demonstration of NASA's IMPACT Tradespace Analysis Tool

BACKGROUND NASA’s human exploration spaceflight missions to the Moon and Mars present unprecedented challenges for in-mission medical care. A greater distance from Earth will mean increased mission durations, communication delays, limited to no resupply opportunities, and constraints on the evacuation of ill or injured crew. Mass, volume, and power will be limited while higher demands will be placed on the crews to manage medical events. NASA’s Moon to Mars exploration strategy outlines increasingly complex Artemis missions both in terms of duration and operations. In these more challenging deep space missions, it is important to quantitatively estimate the human system risk attributable to medical conditions and use these estimates to advance medical system design. METHODS IMPACT (Informing Mission Planning via Analysis of Complex Tradespaces) is a probabilistic risk assessment (PRA) and tradespace analysis tool developed by NASA to advance exploration mission medical system design. IMPACT v1.0 includes a novel evidence library baselined to exploration environments; an expanded list of 119 medical conditions; a large increase in the number of medical resources and the flexibility of their use; and the ability for rapid and iterative analysis. Medical system risk estimates include loss of crew life, consideration of the need for return to definitive care (medical evacuation), and an estimate of crew time affected due to medical conditions. A notional long duration lunar orbit and lunar surface design reference mission (DRM) was chosen with a 4-astronaut crew to mimic a foundational exploration Artemis mission. The DRM profile includes outbound transit on Orion, Gateway space station rendezvous in lunar orbit, 6 months on the Lunar surface with extravehicular activity (EVA), return rendezvous with Gateway, and transit back to Earth. RESULTS/DISCUSSION: Overall, IMPACT successfully quantified medical risk and derived an optimal medical system to support crew on a long duration lunar mission. In this DRM, the calculated loss of crew life from a medical event was 0.008 events per mission, risk of potential need for evacuation was 0.30 events per mission, and cumulative crew time affected by medical conditions was 103 days. The medical conditions that most contributed to medical risk were decompression sickness, trauma, and respiratory failure. The conditions that had the largest effects on crew performance included musculoskeletal injuries and lunar dust exposure. The IMPACT-generated medical system included resources that target the most common and highest risk conditions and performed as expected. This demonstrates the value of the IMPACT tool in medical system design for human exploration spaceflight missions.

Arian Anderson↗
NASA NTRSDate not supplied

NASA Progress on the Development and Qualification of a 12-kW Hall-Effect, Solar Electric Propulsion Thruster

I. Motivation and Background Beginning in 2014, the National Aeronautics and Space Administration (NASA) Space Technology Mission Directorate (STMD) began a project to increase the state of the art for the Hall-Effect Solar Electric Propulsion (SEP) technology. The resulting Advanced Electric Propulsion System (AEPS) project has developed a 12 kW Hall Current Thruster in support of the NASA mission to establish a permanent human presence in lunar orbit and to land the next American astronauts on the South Pole of the Moon. The project is led by the NASA Glenn Research Center, supported by the Jet Propulsion Laboratory and development, qualification & flight hardware all provided by L3 Harris Aerojet Rocketdyne (AR).The AEPS project has completed the development testing of a high power, solar electric propulsion Hall Current thruster that will be used on the NASA Power & Propulsion Element (PPE) of the Gateway space station. NASA initially built three Technology Development Units to understand key characteristics of the hall-effect rocket with magnetic shielding. The design led to development testing on two Engineering Test Unit Thrusters and multiple critical components. The project has begun production of the three flight thrusters and entered qualification testing at the component and thruster levels. II. Approach NASA and AR teams completed all development phases of the project, including full development and integration testing of the Engineering Model hardware, Critical Design Review, and ground test equipment validation, as well as fabrication and acceptance testing of the initial qualification thruster. Qualification and verification of the environmental and life requirements of the AEPS design was initiated in the Fall of 2023 and will be accomplished on two thruster units and using a series of component-level tests during 2024 and 2025. Environmental testing will incorporate functional reference firings, shock, vibration, and Thermal Vacuum (TVAC) testing. Life verification will assess the thruster wear and performance over the lifetime of the Gateway spacecraft. Critical component qualification tests include cathode heater, magnet coils, magnet heaters, temperature sensors, and a cathode assembly that will undergo life cycle testing on multiple units. Flight thrusters will complete assembly and acceptance testing and be delivered to the PPE program in early 2025. III. Preliminary and Anticipated Results The program has completed the acceptance testing, including dynamic testing and hot fire characterization, of the first qualification thruster. In the Fall of 2023, the program entered the environmental qualification phase for thruster testing. This paper will present an overview of the AEPS thruster project, thruster capabilities and flight design, preliminary results from the thruster acceptance and qualification testing, component life cycle testing and flight hardware status.

Clayton Kachele↗
NASA NTRS2022

Medical Risk Estimates and Clinical Capability Needs for a Late Artemis Mission

BACKGROUND Human exploration spaceflight missions to the Moon and Mars present unprecedented challenges for in-mission medical care. Compared with the ISS, the greater distance from Earth will mean increased mission durations, communication delays, limited to no resupply opportunities, and significant limitations on the evacuation of ill or injured crew. Spacecraft mass, volume, and power will be curtailed while higher demands will be placed on the crew’s knowledge, skills, and abilities. In this higher risk environment, it is important to: a) quantitatively estimate human system risk attributable to medical conditions, a process known as Probabilistic Risk Analysis, and b) use these estimates to inform medical system design. IMPACT (Informing Mission Planning via Analysis of Complex Tradespaces) is a PRA and medical trade space analysis tool developed by NASA to advance exploration mission medical system design. IMPACT v1.0 improves upon and will soon replace NASA’s existing tool, the Integrated Medical Model, with: a novel evidence base baselined to exploration environments; an expanded list of 119 medical conditions; a significant increase in the number of medical resources that can be utilized and in the flexibility of their use; and the modelling of time lost performing mission-specific tasks due to medical conditions. DISCUSSION: This abstract will present IMPACT estimates of medical system risk and clinical capability needs for an extended duration Artemis mission of approximately 9 months, with phases including outbound transit, 3 months on the Lunar Gateway space station, 3 months on the Lunar surface with EVAs, 3 months on Gateway (simulating the return phase of a Mars mission), and transit back to Earth. Medical system risk estimates include loss of crew life (LOCL), consideration of medical evacuation (known as return to definitive care –RTDC), and an estimate of crew time list due to medical conditions (Task Time Lost –TTL). The presentation will also describe the medical conditions that are the greatest drivers of risk as well as the clinical capabilities and resources that have the largest effect on risk.

A Anderson↗
NASA NTRSDate not supplied

Stochastic Verification by Analysis for Autonomous Systems Management Architecture (ASMA)

The Gateway Vehicle Systems Manager (VSM) is the top-level of a distributed, hierarchical software control system. VSM is data-driven and will make decisions related to mission, fault, resource management and vehicle control. These attributes combined with a high degree of autonomy make it susceptible to emergent behavior. In order to achieve the high level of confidence needed in this critical system, the VSM team has developed a multifaceted verification strategy employing traditional verification techniques, simulation, model checking, and runtime verification. Individual algorithms are verified using conventional testing and model checking using assume-guarantee contracts. A discrete event-based simulation approach is being developed to verify timelines. This presentation describes an enhancement to the verification approach using analysis to enhance system robustness by detecting and resolving the potential for emergent behavior. The verification by analysis employs a Software in the Loop (SITL) environment with real flight software executing on emulated processors, simulations of vehicle subsystems, flight dynamics, and human inputs. Since the possible input space and configuration data set are too large for exhaustive testing, a Monte Carlo approach is used to cover feasible scenarios, augmented with corner cases and known higher-risk scenarios. A key problem in using Monte Carlo-based system verification is evaluating test results to ensure that system behavior is correct. The presentation describes the approach the VSM team uses to monitor behavior for compliance with predetermined boundaries and to identify anomalous behavior for further analysis. This presentation describes the multi-level systems approach to verification, and the simulation-based layer that covers the feasible state space: 1. Overview of the Gateway VSM 2. Special challenges due to heterogeneous, hierarchical architecture 3. Modeling and simulation environment using flight software and system simulations 4. Developing input sets to ensure state-space coverage 5. Developing model and data configuration sets to ensure model coverage 6. Interpreting results without predetermined outcomes 7. Lessons learned and future work

Verification and Validation↗
NASA NTRSDate not supplied

Advances in High-rate Delay Tolerant Networking On-board the International Space Station

The High-rate Delay Tolerant Networking (HDTN) project at the NASA John H. Glenn Research Center (GRC) is developing a performance optimized Delay Tolerant Networking (DTN) implementation which is able to provide reliable multigigabit per second automated network communications for near-Earth and deep space missions. To that end, this paper provides an overview of the testing and integration efforts culminating in a high-rate DTN demonstration onboard the International Space Station (ISS). Over several years, the HDTN team has performed a series of end-to-end tests between the Software Development and Integration Laboratory (SDIL) at the Lyndon B. Johnson Space Center (JSC) and Marshall Space Flight Center’s Huntsville Operations Support Center (HOSC). The testing has focused on a realistic emulation of the ISS Ku-band RF link, which operates at a maximum of 500 Mbps downlink with a 600 ms round-trip time. In this environment, the HDTN onboard gateway has been tested for interoperability with ISS payload nodes and the DTN ground gateway, store and forward capability, reliable transport using the Licklider Transmission Protocol (LTP), and successful recovery from unexpected loss of signal. In addition to integration testing, HDTN has developed a series of software engineering practices to ensure the stability and maturity of the implementation. As the result, HDTN has successfully demonstrated high-rate DTN services onboard the ISS. This paper concludes with a summary of preliminary flight testing results from the Integrated LCRD LEO User Modem and Amplifier Terminal networking experiments.

Delay tolerant networking↗
NASA NTRS2024

Assessment of Base Loads Generated by an Exercise Device in the HALO Module

The purpose of this document is to prescribe a uniform procedure that can be used to postprocess base loads generated by a crew member and an exercise device in the Gateway Habitation and Logistics Outpost (HALO) module. This memo has three primary sections. First, the exercise loads pass through a Vibration Isolation and Stabilization (VIS) system notionally depicted in Figure 1 for the purpose of preliminary analyses. This is described in Section 2. Next, these loads are processed in frequency domain as explained in Section 3. Finally, the resulting outputs are compared with a Gateway Program Loads and Dynamics (L&D) allocation given to the VIS system. This information is provided in Section 4.

Exercise↗
NASA NTRSDate not supplied

Flight Dynamics Analysis of Lunar Fly-By Altitudes and Near Rectilinear Halo Orbit (NRHO) Resonances With Applications to NASA's Artemis Program

As the interest in lunar exploration grows exponentially, many companies and government agencies around the world are looking to establish presence on the lunar surface. With NASA’s Artemis program and Lunar Gateway, NASA seeks to return to the moon and for exploration. To achieve such goals, many orbit regimes and patterns were explored. Due to its minimal station keeping requirements and communications access, a specific set of Halo Orbits known as Near Rectilinear Halo Orbits (NRHO) was selected for use cases in both NASA’s Artemis Program as well as Lunar Gateway. The primary objective of this effort is to perform a flight dynamics analysis, which analyzes trajectories targeting specific lunar fly-by altitudes and NRHO Resonances in the L2 Southern Family.

NASA↗
NASA NTRSDate not supplied

Using Thermal Desktop to Determine Equivalent Solar Hours on Spacecraft Surfaces

Equivalent solar hours (ESH) are the duration of exposure of a surface to solar radiation, particularly ultraviolet (UV) radiation. Since UV light causes degradation to optical properties of thermal control surfaces, the determination of ESH is important to calculate end of life (EOL) optical properties for spacecraft external surfaces. A higher ESH value generally correlates to greater UV degradation experienced by the surface, resulting in an increase in solar absorptivity. This paper details a novel approach for calculating ESH using Thermal Desktop. Since the ESH value is useful for thermal analysts, this technique is beneficial to quickly perform the analysis internally with tools readily available without relying on external support and funding. The example presented in this paper shows how this method was developed and used for NASA's lunar Gateway spacecraft. This method of analysis is used to calculate ESH for the transit, assembly in orbit, and operational phases for Gateway, utilizing each of the program’s planned configurations throughout its 15-year lifetime. ESH values were calculated using the Monte-Carlo ray tracing capability of Thermal Desktop using both direct solar heating and indirect solar heating due to reflections from other surfaces. The output of this analysis includes an ESH gradient map across the spacecraft. Post-processing of these results enabled identification of the average and maximum ESH on critical surfaces such as radiators. The final ESH values for each surface are then used for determination of EOL optical properties.

Thermal Control↗
NASA NTRS2024

MBSE (SysML) and Digital Twin Integration to Support Engineering Analysis & Design

Problem Statement: The complexity of Gateway systems and of managing the integrated safety analysis have made traditional methods of engineering analysis and design increasingly challenging. To address these challenges, a prototype that integrate Model-Based Systems Engineering (MBSE) with Digital Twin technology has been developed to demonstrate the utilities and functions. Project Goal: Develop a prototype of a Digital Twin Of Gateway ECLSS IMV system to enhance fault management analysis through collaboration, visualization, and simulation. Overall Project Results / Accomplishments: - Developed extension to streamline the integration of SysML models with the Digital Twin platform - Demonstrated the capability to aggregate any relevant information and provide simulation integration within the DT prototype. - Generated digital twin simulation using SysML Activity Diagrams - Implemented a complex trade study use case based on the integrated SysML-Digital Twin infrastructure

MBSE↗
NASA NTRS2025

Transit Habitat Government-Reference Conceptual Design Reaction Control System Propulsion Concept Design Data Book

The function of Transit Habitat (TH) Reaction Control System (RCS) propulsion is to provide free-flying spacecraft capabilities and to augment Gateway stack control when docked on Gateway. The requirements of multiple propellant replenishments and extensive life operation have significant impacts on selection of the propulsion system concept and components for the RCS. The intent of this document is to provide insight into the government-reference conceptual design of a propulsion system for TH element. A pressure-fed hypergolic bi-propellant system is the assumed propulsion approach for the RCS. Its architectural concept is being traded within the NASA Moon to Mars architecture. A pressure-regulated system is examined. The propellants under consideration are Monomethyl Hydrazine (MMH) and Mixed Oxides of Nitrogen with 3% Nitric Oxide (MON3). A peer review was conducted to assess the flow schematic design and propulsion component selection, compliant with a set of assumed requirements. Redundant components to satisfy one-fault tolerance for function and two-fault tolerance against catastrophic events are incorporated in the propulsion concept design. Instrumentation laid out on the schematic would be used to gather data to monitor the health of the propulsion system and to support quantity gauging of the propulsion system fluids. Venting propellant ullage gas overboard during the refilling operations poses a significant concern to the external surfaces of the TH. A liquid/gas separator would be required to eliminate, or at least reduce, the amount of liquid propellant expelled in the vent gas mixture. The technology readiness level of the phase separator for the TH must be advanced. Metal diaphragm and non-positive-expulsion PMD propellant tank systems were traded against each other, with the PMD architecture being selected. A blowdown concept is also considered for the TH RCS propulsion. Its fluid schematic is derived from the pressure-regulated schematic with removal of assemblies involving the helium pressurization and ullage venting. Its system wet mass is 10% heavier than the pressure-regulated due to thruster performance loss and larger propellant tanks. There is no firm constraint on the propulsion system mass at this phase of the design. The blowdown concept can offer reduction in component count and operation, that would lead to a more reliable propulsion system. The blowdown concept would also benefit avionics, thermal, power, and structures on the TH. Assessing these benefits will be carried as a future work. Drawbacks of thrust and minimum impulse bit (MIB) variations due to the blowdown operation would be acceptable to Guidance, Navigation, and Control (GNC). Although the blowdown concept has been selected as a current baseline, further evaluation of the concept will be the subject of future work to ensure that the blowdown propulsion operation is appropriate for the HT RCS propulsion. This document also highlights key trade studies and design decisions, including pros and cons of the selected concept. Other appropriate options for components are pointed out for future assessments. Additional background information and documents for further review are referenced in this report.

spacecraft propulsion↗
NASA NTRSDate not supplied

Dry Saliva Development-Artemis

Prior to the deployment of prolonged deep space missions which may carry increased crew health risks, it is essential to determine the effect that missions beyond the Van Allen Belt will have on physiology. Historically the National Aeronautics and Space Administration (NASA), Human Research Program (HRP) has developed, conducted, and delivered research findings and countermeasures that will maintain the health and safety of crews aboard the International Space Station (ISS) in anticipation of future exploration class missions. To support these objectives, research operations on ISS typically include the collection and storage of human physiological samples and their return to Earth for analysis. Transition to Gateway and Artemis lunar exploration will limit the available up mass and biosample return capability resulting in new challenges to monitor crew health during the mission. The Artemis lunar missions provide a perfect opportunity to assess new technology that could support crew biosample return that is compatible with the severe operational constraints of Artemis mission design. Dried biosample chemistry analysis is a potential technology that can enable the collection of samples and tracking of crew health during these exploration class missions. The development and implementation of dried biosample chemistry technology for tracking immune health, viral reactivation and hormone fluctuations provide a simple alternative strategy for sample collection and sample return (light weight non-conditioned stowage option) for the continuation of human research during Artemis missions. Saliva is established as an informative biosample that has both its own unique available analytes as well as others that are also present in blood. Saliva is already routinely collected from ISS astronauts for the detection of stress hormones and latent virus DNA. The ‘Dry Saliva’ book sample collection/storage protocol, already successfully deployed to ISS, represents a perfect method for collecting biosamples from Gateway and Artemis astronauts because it requires a simple, non-invasive sample collection protocol, minimum volume, and uses non-conditioned storage. We are currently conducting an expanded stability study of the dry saliva analyte platform to include additional stress hormones, cytokines, antimicrobial proteins, and latent virus DNA as well as other markers of immunity and inflammation. Validation testing on parabolic flight will establish collection methods for saliva and blood to dry sampling substrates to finalize the collection protocols for flight. For the new expanded analyte stability study, a short-term stability study with time points out to 14 days has been completed with analysis underway to determine whether additional analytes could be recovered, as well as assessing the best storage conditions for the samples collected. In parallel, a long-term stability study is being conducted out to 1 year to improve the stability of some unstable analytes. To this end, the NASA Johnson Space Center’s Immunology/Virology lab is currently finalizing the saliva dry chemistry platform, including assay compatibility and stability studies. This technology is approved to be implemented, as part of the ‘Biomarkers’ study, during Artemis II through Artemis IV lunar missions.

Mayra Nelman-Gonzalez↗
NASA NTRS2025

Robust Trajectory Optimization for NRHO Rendezvous Using SPICE Kernel Relative Motion

In this paper, robust optimization is performed on trajectory correction maneuvers during the lunar lander return phase of an Artemis mission, treating the trajectory from one hour after low lunar orbit departure to arrival in the vicinity of the lunar Gateway as a relative motion problem. To enable rapid stochastic optimization techniques requiring many candidate trajectories, SPICE kernel relative motion as implemented by the Quadratic Interpolated State Transition (QIST) system is used as the underlying dynamics propagation. The optimization is performed with a genetic optimizer using linear covariance (LinCov) software in a simplified operational context, taking into account the availability of navigation sensors with varying measurement models, ranges, and accuracies. No numerical integration is used, since the relative motion around Gateway is fully characterized with the a priori computation of the QIST coefficients. Maneuver placements are computed to optimize the minimum 3σ delta-v of the trajectory, the position dispersion at a target point, and a convex combination of these two metrics. An order of magnitude runtime improvement is provided over legacy methods with less than 10% error introduced. All QIST results are shown to be in-family with legacy methods. The tradespace for optimal delta-v design is found to range from 77.0 to 93.9 m/s, while the range of optimal dispersion is between 1.4 and 11.7 km.

Relative Motion↗
DOE OSTI2020

Intra-microgrid communication architecture

A microgrid according to an exemplary aspect of the present disclosure includes, among other things, a plurality of intelligent electronic devices configured to communicate directly with one another in a first language. Each of the intelligent electronic devices includes a controller and a gateway. The gateway is configured to convert incoming messages from the first language to a second language native to the controller. The first language is different than the second language. A method is also disclosed.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2020

Area Lighting Yuma Sector Border Patrol Area, AZ. SSL Evaluation [Brief]

Along the Yuma Sector Border Patrol Area in Yuma, Arizona, the GATEWAY program conducted a trial evaluation in which the incumbent quartz metal halide area lighting was replaced with LED at three pole locations, and illuminance measurements were recorded initially and at 2500 hours, 5000 hours, 7000, and 11,000 hours of operation. Additionally, four second-generation LED luminaires installed as part of the full installation were evaluated initially and again after 4,000 hours of operation. While the initial energy, lighting quality, and maintenance benefits relative to the incumbent high-pressure sodium system were very satisfactory, the study raises important questions regarding the long-term performance of LED lighting systems in high-temperature environments.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS2019

Sensor Configuration Trade Study for Navigation in near Rectilinear Halo Orbits

Gateway is a NASA program planned to support a human space explorationand prove new technologies for deep space exploration. One of the Gatewayrequirements is to operate in the absence of communications with the Deep SpaceNetwork (DSN) for a period of at least 3 weeks. In this paper three types ofonboard sensors (a camera for optical navigation, a GPS receiver, and X-ray navigation),are considered to enhance its autonomy and reduce the reliance on DSN.A trade study is conducted to explore alternatives on how to achieve autonomy andhow to reduce DSN dependency while satisfying navigation performance requirements.Using linear covariance analysis, the performance of a navigation systemusing DSN and/or the other sensors is shown.

Gateway↗