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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Assembly and Integration Status of a High Fidelity Ground Test Bed for the Water Processor Assembly

The Water Recovery System (WRS) is a critical component of life support aboard the International Space Station (ISS) and will play an essential role in future missions beyond Low Earth Orbit (LEO). Its primary functional units – the Urine Processor Assembly (UPA), Brine Processor Assembly (BPA), and Water Processor Assembly (WPA) – must be evaluated for extended operation, dormancy resilience, material obsolescence, and reliability under exploration-driven constraints. Ground testing is vital for developing these technologies and generating statistically relevant reliability assessments, which requires extended runtime under integrated, Flight-like conditions. Currently, no high-fidelity, fully integrated WPA ground test bed exists to support these objectives. To address this gap, NASA is developing a WPA test bed at Marshall Space Flight Center (MSFC) that combines downgraded ISS flight hardware with functionally flight-like components in a cost-effective configuration while maintaining priority hardware investigations. This paper describes the current status of hardware assembly and integration, outlines key challenges such as simulating microgravity effects and mitigating obsolescence, and presents future test objectives including software development, reliability assessments, dormancy studies, and exploration-oriented upgrades.

Water Processor Assembly↗
NASA NTRS2006

Further Investigations of High Temperature Knitted Spring Tubes for Advanced Control Surface Seal Applications

Knitted metallic spring tubes are the structural backbones that provide resiliency in control surface seals for use on current and future reusable space launch vehicles. Control surface seals fill the space between movable control surfaces such as body flaps, rudders and elevons, and the static body structures to which they are attached. These seals must remain in continuous contact with opposing surfaces to prevent the ingestion of damaging hot gases encountered during atmospheric re-entry. The Inconel X-750 (Special Metals Corporation) spring tube utilized in the baseline control surface seal shows significant resiliency loss when compressed at temperatures as low as 1200 F. High temperature compression testing and microstructural analysis show that creep is the dominant deformation mechanism leading to permanent set and resiliency loss in tested spring tube samples. Additional evaluation using a structured design of experiments approach shows that spring tube performance, primarily high temperature resiliency, can be enhanced through material substitution of Rene 41 (Allvac) alloy (for the baseline Inconel X-750 material) when coupled with specialized thermal processing.

Taylor, Shawn C.↗
NASA NTRS2010

An Adaptive Control Technology for Safety of a GTM-like Aircraft

An adaptive control architecture for safe performance of a transport aircraft subject to various adverse conditions is proposed and verified in this report. This architecture combines a nominal controller based on a Linear Quadratic Regulator with integral action, and an adaptive controller that accommodates actuator saturation and bounded disturbances. The effectiveness of the baseline controller and its adaptive augmentation are evaluated using a stand-alone control veri fication methodology. Case studies that pair individual parameter uncertainties with critical flight maneuvers are studied. The resilience of the controllers is determined by evaluating the degradation in closed-loop performance resulting from increasingly larger deviations in the uncertain parameters from their nominal values. Symmetric and asymmetric actuator failures, flight upsets, and center of gravity displacements, are some of the uncertainties considered.

Matsutani, Megumi↗
NASA NTRS2002

Advanced Control Surface Seal Development at NASA GRC for 3rd Generation RLV

NASA's Glenn Research Center (GRC) is developing advanced control surface seal technologies for the 3rd Generation RLV program. GRC has designed several new test rigs to simulate the temperatures, pressures, and scrubbing conditions that seals would have to endure during service. A hot compression test rig and hot scrub test rig are being developed to perform tests at temperatures up to 3000 F. Another new test rig allows simultaneous seal flow and scrub tests at room temperature to evaluate changes in seal performance with scrubbing. High temperature ceramic preloading devices are being developed and evaluated as ways to improve seal resiliency.

Dunlap, Patrick H., Jr.↗
NASA NTRSDate not supplied

Evaluating the Use of High-Fidelity Simulator Research Methods to Study Airline Flight Crew Resilience

As it evolves, aviation will continue to require integration of a wide range of safety systems and practices, some of which are already in place and others that are yet to be developed. New concepts in system safety thinking have emerged to consider not only what may go wrong, but also what can be learned when things go right during commercial flight operations. Taken together, these complementary perspectives form a more comprehensive approach to systemsafety thinking that can help to recognize and preserve the resilient performance capabilities currently provided by humans. A need exists, however, for research methods to enable better understanding of the human contributions to aviation safety. NASA’s System-Wide Safety Project supports research on using flight simulation methods to study operator resilience and safety-producing behaviors. Building on prior NASA efforts investigating procedural non-adherences during area navigation standard terminal route arrivals, a high-fidelity commercial aviation line operational simulation (LOS) experiment has been designed to study how flight crews anticipate, monitor for, respond to, and learn from expected and unexpected disturbances during these operations. A diverse set of LOS scenarios were developed to simulate highly realistic, complex, but routinely encountered operational situations. Each scenario provided multiple opportunities to collect data on how flight crews manage threats and errors, as well as novel opportunities to observe resilient and safety-producing behaviors. The experimental design, implications for the study of safety-producing behaviors using simulation, and considerations for airline pilot training will be discussed.

Chad L Stephens↗
NASA NTRSDate not supplied

Mitigation of Silver Ion Loss from Solution by Polymer Coating of Metal Surfaces, Part IV

Ionic silver (Ag+) biocide is a leading candidate to provide residual microbial control in spacecraft potable water systems, but suffers from rapid concentration loss due to interactions with the metallic storage containers and tubing. One approach to resolve this problem is the coating of metal surfaces with an inert barrier film. In previous reports, we have described our investigations addressing Ag+ loss mitigation and adhesion performance of parylene barrier coatings on coupons of several metal alloys and 316Ltubing under static immersion. In such conditions, parylene-C and -AF4 coatings have shown excellent Ag+loss mitigation and mixed long-term adhesion performance, depending on parylene species and substrate surface chemistry/structure. In Part IV of this series, we report on our work to investigate the performance of parylene-C barrier coatings, under more challenging and realistic conditions, in order to evaluate potential suitability for use. The resilience and associated Ag+ loss with Parylene-C coating on½” (12.7 mm)316L tubing and fittings under medium-term immersion and repeated fitting dis/reassembly were investigated. Potential mechanical challenges to barrier coatings in spacecraft potable water systems were investigated, with two main focuses being identified: liquid flow/pressure cycling in tubing and cyclic operation of bellows in positive-expulsion storage tanks. Two corresponding testbeds for experimental characterization of coating performance were developed. In the Flow/Pressure Testbed System, Ag+ solution will be pumped through internally coated 316L tubing, with optional pressure cycling. In the Bellows Tank Testbed System, an internally coated edge-welded 316L bellows containing Ag+ solution will be cyclically extended and compressed, analogous to the operation of bellows tanks used for potable water storage and delivery on the International Space Station. The design and operation of these testbeds are described. Finally, the Ag+ adsorption and saturation behaviors of Kalrez and Viton, for potential use as seal materials in fittings and other connections, were characterized in limited experiments.

mitigation↗
NASA NTRS2016

NASA Collaborative Approach Mitigates Environmentally-Driven Obsolescence

National Aeronautics and Space Administration (NASA) missions, like Department of Defense (DoD) organizations, require the rigorous testing and qualification of critical materials. Obsolescence supply risks created by environmental requirements can affect the cost, schedule and performance of NASA missions and the resilience of critical infrastructure. The NASA Technology Evaluation for Environmental Risk Mitigation (TEERM) Principal Center helps to identify obsolescence supply risks driven by environmental requirements and works proactively with NASA Centers and Programs, the DoD, the European Space Agency (ESA) and other agencies and partners to identify and evaluate environmentally friendly alternatives. TEERM tracks environmental regulations, identifies the potential loss of material availability and works with NASA programs and Centers to evaluate potential impacts through a risk assessment approach. TEERM collaborative projects identify, demonstrate and evaluate commercially viable alternative technologies and materials. A major focus during the Space Shuttle Program was the need to replace ozone depleting substances that were used in spray foam and cleaning applications. The potential obsolescence of coatings containing hexavalent chromium and the risks associated with lead free solder were also of concern for the Space Shuttle and present ongoing risks to new programs such as the Space Launch System. One current project teams NASA and ESA in the evaluation and testing of individual coatings and coating systems as replacements for hexavalent chromium coatings in aerospace applications. The proactive, collaborative approach used by TEERM helps reduce the cost burden on any one team partner, reduces duplication of effort, and enhances the technical quality and overall applicability of the testing and analysis.

environmentall-driven obsolescence↗
NASA NTRS2009

Mitigation of EMU Cut Glove Hazard from Micrometeoroid and Orbital Debris Impacts on ISS Handrails

Recent cut damages sustained on crewmember gloves during extravehicular activity (ISS) onboard the International Space Station (ISS) have been caused by contact with sharp edges or a pinch point according to analysis of the damages. One potential source are protruding sharp edged crater lips from micrometeoroid and orbital debris (MMOD) impacts on metallic handrails along EVA translation paths. A number of hypervelocity impact tests were performed on ISS handrails, and found that mm-sized projectiles were capable of inducing crater lip heights two orders of magnitude above the minimum value for glove abrasion concerns. Two techniques were evaluated for mitigating the cut glove hazard of MMOD impacts on ISS handrails: flexible overwraps which act to limit contact between crewmember gloves and impact sites, and; alternate materials which form less hazardous impact crater profiles. In parallel with redesign efforts to increase the cut resilience of EMU gloves, the modifications to ISS handrails evaluated in this study provide the means to significantly reduce cut glove risk from MMOD impact craters

Ryan, Shannon↗
NASA NTRS1992

Effect of temperature and gap opening rate on the resiliency of candidate solid rocket booster O-ring materials

In the redesign of the Space Shuttle solid rocket motor following the Challenger accident, the field and nozzle-to-case joints were designed to minimize gap opening caused by internal motor pressurization during ignition. The O-ring seals and glands for these joints were designed both to accommodate structural deflections and to promote pressure assisted sealing. The resiliency behavior of several candidate O-ring materials was evaluated for the effects of temperature and gap opening rates. The performance of three of the elastomeric materials was tested under the specific redesign gap opening requirement. Dynamic flexure conditions unique to launch produce low frequency vibrations in the gap opening. The effect of these vibrations on the ability of the O-ring to maintain contact with the sealing surface was addressed. The resiliency of the O-ring materials was found to be extremely sensitive to variations in temperature and gap opening rate. The top three elastomeric materials tracked the simulated solid rocket booster (SRB) field joint deflection at 75 and 120 F. The external tank/SRB attach strut load vibrations had a negligible effect on the ability of the O-ring to track the simulated SRB field joint deflection.

Lach, Cynthia L.↗
NASA NTRS2002

Measuring the Resilience of Advanced Life Support Systems

Despite the central importance of crew safety in designing and operating a life support system, the metric commonly used to evaluate alternative Advanced Life Support (ALS) technologies does not currently provide explicit techniques for measuring safety. The resilience of a system, or the system s ability to meet performance requirements and recover from component-level faults, is fundamentally a dynamic property. This paper motivates the use of computer models as a tool to understand and improve system resilience throughout the design process. Extensive simulation of a hybrid computational model of a water revitalization subsystem (WRS) with probabilistic, component-level faults provides data about off-nominal behavior of the system. The data can then be used to test alternative measures of resilience as predictors of the system s ability to recover from component-level faults. A novel approach to measuring system resilience using a Markov chain model of performance data is also developed. Results emphasize that resilience depends on the complex interaction of faults, controls, and system dynamics, rather than on simple fault probabilities.

Bell, Ann Maria↗
NASA NTRS2019

Cloud Influence on ERA5 and AMPS Surface Downwelling Longwave Radiation Biases in West Antarctica

The surface downwelling longwave radiation component (LW[down arrow]) is crucial for the determination of the surface energy budget and has significant implications for the resilience of ice surfaces in the polar regions. Accurate model evaluation of this radiation component requires knowledge about the phase, vertical distribution, and associated temperature of water in the atmosphere, all of which control the LW[down arrow] signal measured at the surface. In this study, we examine the LW[down arrow] model errors found in the Antarctic Mesoscale Prediction System (AMPS) operational forecast model and the ERA5 reanalysis model relative to observations from the AWARE campaign at McMurdo Station and the West Antarctic Ice Sheet (WAIS) Divide. The errors are calculated separately for observed clear-sky conditions, ice-cloud occurrences, and liquid-bearing cloud layer (LBCL) occurrences. The analysis results show a tendency in both models at each site to underestimate the LW[down arrow] during clear sky conditions, high error variability (standard deviations > 20 W/m[exp2]) during any type of cloud occurrence, and negative LW biases when LBCLs are observed (bias magnitudes > 15 W/m[exp2] in tenuous LBCL cases; > 43 W/m[exp2] in optically thick/opaque LBCLs instances). We suggest that a generally dry and liquid-deficient atmosphere responsible for the identified LW[down arrow] biases in both models is the result of excessive ice formation and growth, which could stem from model initial and lateral boundary conditions, microphysics scheme, aerosol representation, and/or limited vertical resolution.

Israel Silber↗
NASA NTRS2009

Integrated Resilient Aircraft Control Project Full Scale Flight Validation

Objective: Provide validation of adaptive control law concepts through full scale flight evaluation. Technical Approach: a) Engage failure mode - destabilizing or frozen surface. b) Perform formation flight and air-to-air tracking tasks. Evaluate adaptive algorithm: a) Stability metrics. b) Model following metrics. Full scale flight testing provides an ability to validate different adaptive flight control approaches. Full scale flight testing adds credence to NASA's research efforts. A sustained research effort is required to remove the road blocks and provide adaptive control as a viable design solution for increased aircraft resilience.

Bosworth, John T.↗
NASA NTRS2016

Self-Guided Multimedia Stress Management and Resilience Training for Flight Controllers

Stress and anxiety-related problems are among the most common and costly behavioral health problems in society, and for those working in operational environments (i.e. astronauts, flight controllers, military) this can seriously impact crew performance, safety, and wellbeing. Technology-based interventions are effective for treating behavioral health problems, and can significantly improve the delivery of evidence-based health care. This study is evaluating the effectiveness, usefulness, and usability of a self-guided multimedia stress management and resilience training program in a randomized controlled trial (RCT) with a sample of flight controllers at Johnson Space Center. The intervention, SMART-OP (Stress Management and Resilience Training for Optimal Performance), is a six-session, cognitive behavioral-based computer program that uses self-guided, interactive activities to teach skills that can help individuals build resilience and manage stress. In a prior RCT with a sample of stressed but otherwise healthy individuals, SMART-OP reduced perceived stress and increased perceived control over stress in comparison to an Attention Control (AC) group. SMART-OP was rated as "highly useful" and "excellent" in usability and acceptability. Based on α-amylase data, individuals in SMART-OP recovered quicker and more completely from a social stress test as compared to the AC group [1]. In the current study, flight controllers are randomized either to receive SMART-OP training, or to a 6-week waitlist control period (WLC) before beginning SMART-OP. Eligible participants include JSC flight controllers and instructors without any medical or psychiatric disorder, but who are stressed based on self-report. Flight controllers provide a valid analog sample to astronauts in that they work in an operational setting, use similar terminology to astronauts, are mission-focused, and work under the same broader work culture. The study began in December 2014, and to date 79 flight controllers and instructors have expressed interest in the study, 49 of those were cleared for participation, we have screened 44 for eligibility, and 23 have met inclusion criteria. Recruitment is ongoing and the study will continue until December 2016. Outcome measures include perceived stress, perceived control over stress, resilience, mood, personality, emotion regulation, sleep, health behaviors, and psychophysiological data such as 24-hour heart rate, alpha amylase, and urinary and salivary cortisol. We are also collecting user feedback such as usability, working alliance, usefulness, and treatment credibility.

Rose, R. D.↗
NASA NTRS1990

Genesis lunar outpost criteria and design

This design study--the third in the space architecture series--focused on the requirements of an early stage lunar outpost. The driving assumptions of the scenario was that the base would serve as a research facility and technology testbed for future Mars missions, a habitat supporting 12 persons for durations of up to 20 months, and would sustain the following five experimental facilities: Lunar surface mining and production analysis facility, construction technology and materials testbed, closed environmental life support system (CELSS) test facility, lunar farside observatory, and human factors and environment-behavior research facility. Based upon the criteria set forth in a previous programming document, three preliminary lunar base designs were developed. Each of the three schemes studied a different construction method and configuration. The designs were then evaluated in terms of environmental response, human habitability, transportability, constructability, construction dependability and resilience, and their suitability in carrying out the desired scientific research. The positive points of each scheme were then further developed by the entire project team, resulting in one integrated lunar outpost design.

Hansmann, Timothy↗
NASA NTRSDate not supplied

SysML Success Tree for DAVINCI In-Situ Campaign Requirements Validation and Redundancy Assessment

The DAVINCI mission will scientifically study the Venusian atmosphere to better understand the current state of the planet and its evolutionary history. This will be accomplished by deploying a descent probe to collect in-situ atmospheric dynamic and spectroscopic measurements, characterize ambient temperatures and pressures during descent, and surface imaging below the cloud layer. To better characterize the DAVINCI In-Situ Campaign, a success tree, developed in the SysML tool, MagicDraw, was created to define the events necessary to have a successful in-situ campaign, for each phase of the campaign. This success tree was also used to validate DAVINCI Program, Mission, and Element level requirements. In addition, because DAVINCI is a single-string mission, the success tree was also used to identify areas of redundancy and resiliency throughout the campaign. The initial redundancy assessment recommended further on-orbit evaluation of the probe’s communication system, as well as further evaluation of the ability of the mass spectrometer turbo-molecular pump to handle the expected decent environment. During the integration and test phase of the overall mission, the success tree will be used to guide the mission validation process, helping to ensure that the in-situ mission elements can perform in accordance with the DAVINCI In-Situ Concept of Operations document.

model-based↗
NASA NTRSDate not supplied

SysML Success Tree for DAVINCI In-Situ Campaign Requirements Validation and Redundancy Assessment

The DAVINCI mission will scientifically study the Venusian atmosphere to better understand the current state of the planet and its evolutionary history. This will be accomplished by deploying a descent probe to collect in-situ atmospheric dynamic and spectroscopic measurements, characterize ambient temperatures and pressures during descent, and surface imaging below the cloud layer. To better characterize the DAVINCI In-Situ Campaign, a success tree, developed in the SysML tool, MagicDraw, was created to define the events necessary to have a successful in-situ campaign, for each phase of the campaign. This success tree was also used to validate DAVINCI Program, Mission, and Element level requirements. In addition, because DAVINCI is a single-string mission, the success tree was also used to identify areas of redundancy and resiliency throughout the campaign. The initial redundancy assessment recommended further on-orbit evaluation of the probe’s communication system, as well as further evaluation of the ability of the mass spectrometer turbo-molecular pump to handle the expected decent environment. During the integration and test phase of the overall mission, the success tree will be used to guide the mission validation process, helping to ensure that the in-situ mission elements can perform in accordance with the DAVINCI In-Situ Concept of Operations document.

ConOps↗
NASA NTRSDate not supplied

SysML Success Tree for DAVINCI In-Situ Campaign Requirements Validation and Redundancy Assessment

The DAVINCI mission will scientifically study the Venusian atmosphere to better understand the current state of the planet and its evolutionary history. This will be accomplished by deploying a descent probe to collect in-situ atmospheric dynamic and spectroscopic measurements, characterize ambient temperatures and pressures during descent, and surface imaging below the cloud layer. To better characterize the DAVINCI In-Situ Campaign, a success tree, developed in the SysML tool, MagicDraw, was created to define the events necessary to have a successful in-situ campaign, for each phase of the campaign. This success tree was also used to validate DAVINCI Program, Mission, and Element level requirements. In addition, because DAVINCI is a single-string mission, the success tree was also used to identify areas of redundancy and resiliency throughout the campaign. The initial redundancy assessment recommended further on-orbit evaluation of the probe’s communication system, as well as further evaluation of the ability of the mass spectrometer turbo-molecular pump to handle the expected decent environment. During the integration and test phase of the overall mission, the success tree will be used to guide the mission validation process, helping to ensure that the in-situ mission elements can perform in accordance with the DAVINCI In-Situ Concept of Operations document.

model-based↗