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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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At least 469 records · Page 26
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Update to Developing a Multi-bioreactor Test Stand for the Evaluation of Biofilm Mitigation Technologies

Biofilm formation in spacecraft wastewater systems is a complex and impactful problem. Biomass flowing in these wastewater systems can cause clogging, higher differential pressures, and flow restrictions impacting equipment reliability and function. To explore this issue, the Marshall Space Flight Center’s biofilm test stand was created and has been utilized to examine multiple biofilm mitigation techniques over a long duration test time. This paper is an update to a previous paper, ICES-2021-122, and will serve to discuss the modifications and enhancements to the biofilm test stand. While the previous configuration tested heat treatments and coatings, this phase of testing will examine differing materials, competing bacteria provided by an external bioreactor, a prototype phytoremediation unit, and additional testing with a nutrient filter. Configuration changes include the addition of float switches, adjustment of the drain assembly architecture and additional support hardware for the competing bacteria bioreactor and phytoremediation units.

ECLSS↗
NASA NTRSDate not supplied

Update to Developing a Multi-bioreactor Test Stand for the Evaluation of Biofilm Mitigation Technologies

Biofilm formation in spacecraft wastewater systems is a complex and impactful problem. Biomass flowing in these wastewater systems can cause clogging, higher differential pressures, and flow restrictions impacting equipment reliability and function. To explore this issue, the Marshall Space Flight Center’s biofilm test stand was created and has been utilized to examine multiple biofilm mitigation techniques over a long duration test time. This paper is an update to a previous paper, ICES-2021-122, and will serve to discuss the modifications and enhancements to the biofilm test stand. While the previous configuration tested heat treatments and coatings, this phase of testing will examine differing materials, competing bacteria provided by an external bioreactor, a prototype phytoremediation unit, and additional testing with a nutrient filter. Configuration changes include the addition of float switches, adjustment of the drain assembly architecture and additional support hardware for the competing bacteria bioreactor and phytoremediation units.

ECLSS↗
NASA NTRSDate not supplied

A Cost and Benefit Analysis of Orbital Debris Remediation, Mitigation,Tracking, and Characterization

Orbital debris may collide with crewed and robotic spacecraft, placing them at risk. The wide range of debris, from 9,000-kilogram rocket bodies to millions of millimeter-size debris, has led to a similarly wide range of proposed actions for addressing the risks posed by debris. However, the costs and benefits of these actions have historically been unknown. This is a challenge for decision makers who are choosing which actions to support through technology development or policy changes. NASA’s Office of Technology, Policy, and Strategy is addressing these technical and economic uncertainties by building a capability to (1) complete rigorous calculations of the net present value of each action, (2) identify an optimal portfolio of actions to reduce risk, and (3) quantitatively analyze policies related to space sustainability. This report describes our progress toward that capability and to solicit feedback from the space and economic communities. Our previous work(Colvin, Karcz, and Wusk. 2023), referred to here as Phase 1, assessed the costs and benefits of performing debris remediation on operationally relevant timescales. The current paper summarizes the work of Locke and Colvin (2024), which contains major updates to the risk model used in Phase 1 and expands the breadth of actions considered to include mitigating the creation of debris, improving the ability to track debris, and more methods for cleaning up existing debris. We demonstrate that our approach of measuring risks in dollars allows for the effectiveness of seemingly incommensurate actions to be compared and generates insights that other approaches to measuring risk have missed.

Orbital Debris↗
NASA NTRS2025

Countermeasures for Mitigation of Sensorimotor Decrements Following Head-Down Tilt Bed Rest

BACKGROUND Astronauts experience postflight disturbances in postural and locomotor control due to sensorimotor adaptations during spaceflight. These alterations may have adverse consequences if a rapid egress is required after landing. Although exercise is partially effective for mitigating cardiovascular and muscular deconditioning, additional countermeasures are needed to further preserve sensorimotor function. Proprioception training and electrical muscle stimulation (EMS) are two promising in-flight countermeasures. Since prolonged head down tilt bed rest (HDTBR) is a spaceflight analog for body unloading and causes postural and locomotor control decrements that parallel those observed after spaceflight, it can be used to facilitate the development of these countermeasures. METHODS This study will determine the effects of proprioception training and EMS on functional task performance and sensorimotor function following 60 days of 6° HDTBR. Subjects will be randomly assigned to one of four groups: 1) an EMS arm, 2) a proprioception training arm, 3) an exercise plus proprioceptive training arm, and 4) a control arm. The EMS countermeasure will include daily bilateral stimulation of selected bilateral lower extremity muscles (30 minutes per session). Proprioception training will be performed three days per week (25 minutes per session) consisting of body-loaded postural tasks in the horizontal position on an air bearing sled. Exercise training will mimic current protocols used on the International Space Station, but treadmill aerobic exercise will be replaced with additional cycling aerobic exercise. Primary outcome measures will include pre- and post- HDTBR functional tests that require high demand for dynamic control of postural stability. Secondary measures will be used to explore key physiological changes that underlie countermeasure benefits. All HDTBR and data collection activities will be completed by the German Aerospace Center (DLR) at the :envihab facility. Given the constrained samples size, a Bayesian modelling approach will be used to quantify the probability that there is an effect of a given magnitude. HARDWARE AND PROTOCOL DEVELOPMENT Final hardware modifications and protocol developments were completed in preparation for Campaign 1, which began in September 2024. These included shipment, setup, and operator training for the transportable gravity bed, horizontal squat device, foam obstacle course, EMS devices, leg dexterity system, foot sole skin sensitivity system, and Radiofrequency Echographic Multi Spectrometry (REMS) ultrasound device. In addition, specialized protocols were developed for data collection using DLR’s equipment, including muscle morphology magnetic resonance imaging (MRI), optical coherence tomography, venous blood flow MRI and ultrasound, muscle ultrasound and impedance, and skin blood flow ultrasound. We will present early data from the first campaign, which concluded in November, 2024. These will be compared with previous data from the recent 30-day HDTBR campaigns (Spaceflight associated neuro-ocular syndrome countermeasures (SANS-CM)) conducted at DLR. RELEVANCE The deliverable from this project will be proof-of-concept sensorimotor countermeasure designs for functional task performance with full assessment of efficacy in a spaceflight analog. If one or more countermeasures are effective, they will be translated for validation with the suite of operationally implemented in-flight countermeasures.

T R Macaulay↗
NASA NTRS2018

Agile Approach to Adding Assurance and Mitigating Overall Mission Risk for Orion Software on EM-1

Human-rated missions like Orion are becoming exceedingly complex in terms of software contribution to achieving mission objectives, and this creates a resource challenge for everyone whose job is to add assurance that the mission is going to fly safely. Orion IV&V has addressed this challenge by providing focused assurance results of critical mission capabilities prioritized by a dynamic assessment of risk level. Prior to this approach, Orion IV&V was evaluating areas of risk in much broader, and more static, terms. Due to the Agile software development cycle that Orion follows, IV&V findings were often reported months out of phase with the developer. As a result of evolving the approach to providing assurance on Orion, IV&V is able to incrementally deliver high-priority assurance data and more impactful issues more in phase with the developer activities, thereby increasing the value of the findings to the project. The agile IV&V approach employed by the Orion IV&V team strives to achieve a cadence of delivery that matches the pace of development. This agile approach provides increased flexibility for the assurance provider to become more efficient in reporting assurance conclusions and issues. This presentation will discuss the principles which drive the design of our approach, results to date, and aspirations for long-term performance.

Assurance↗
NASA NTRS2018

Dust Mitigation on Mars Using an Electrostatic Precipitator

The Martian atmosphere contains large amounts of dust, which are lofted by dust devils and dust storms. Some of this dust, particles on the order of 2-4 m, never settle and are constantly present in the atmosphere. Therefore, in order to utilize the planet's atmosphere for production of consumables, like oxygen and methane, this dust must be removed before the commodity production can begin. The electrostatic precipitator is currently being studied at Kennedy Space Center as a realistic option for removing this dust. This project covers the results, to date, of the dust flow initiation, control, and analysis inside the electrostatic precipitator, which is to be modelled after various dusty Martian atmospheric conditions.

electrostatic precipitator↗
NASA NTRS2019

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

Spacecraft potable water systems require a biocidal agent that effectively provides both immediate and residual disinfection over long periods of time. Ionic silver (Ag+) is a leading candidate for this application, but suffers from rapid concentration loss due interactions with the metal storage containers and tubing. In order to maintain biocidal efficacy in systems with long periods of dormancy and to reduce the required rate of Ag+ injection, it is necessary to develop alternative materials and coatings for certified metal alloys that significantly reduce the Ag+ loss. In this work, we investigate the performance of two unusual polymers, Teflon AF 2400 and parylene-AF4, as barrier coatings under immersion in 400 ppb Ag+. We show that 25 m-thick parylene-AF4 is a promising coating with Ag+ losses similar to PTFE. Key challenges with this material include maintenance of adhesion under long-term immersion and control of deposition during the internal coating of high-aspect ratio tubing. Solutions to these problems may including surface structuring of substrates for mechanical anchoring or an alternative parylene-C chemistry (with more stable adhesion), and dynamic spatio-temporal control of substrate temperature, respectively.

water↗
NASA NTRS2020

NASA Engineering and Safety Center Technical Bulletin No. 20-07: Evaluating and Mitigating Liner Strain Spikes in COPV's

Unexpected cracking and leaking in bonded composite overwrapped pressure vessel (COPV) liners occurring in recent test programs have been attributed to liner strain spikes observed through measurement and predicted by analysis. Diminished load transfer between the liner and composite overwrap can lead to localized excessive liner yielding in the dome section. This diminished constraint can occur due to yielding of the adhesive or a manufacturing unbond defect. COPVs should be assessed for susceptibility to this new failure mode.

Evaluating↗
NASA NTRSDate not supplied

Developing Materials and Coating Technologies for Mitigation of Lunar Dust Adhesion and Abrasion

In order to support long duration missions on the Moon’s surface, materials resistant to the harsh lunar environment are critically needed. Lunar dust poses a major threat to the durability of components and vehicles due to its fine, jagged morphology and highly abrasive nature, which enables the particles to adhere and embed into surfaces of components and devices potentially leading to premature failure. Consequently, significant effort within NASA aims to develop novel materials and coating technologies to limit lunar dust adhesion and abrasion by exploring a variety of production routes and examining properties of candidate material systems, including ceramic, metallic and polymeric. Manufacturing methods investigated include traditional powder processing, additive manufacturing and surface modification via laser ablation patterning of bulk materials and coatings. An overview of ongoing NASA materials and coating research and development to enable lunar exploration will be presented.

Materials↗
NASA NTRSDate not supplied

Evolving Role of Aircraft and Airspace Operations for Aerial Fire Mitigation

Various sizes and types of aircraft are envisioned to play a critical role in fighting fires. Multiple aircraft, including drones, operating simultaneously to fight fires requires coordination to maintain effectiveness as well as safety. Presently, firefighting is limited to day time, high visibility, and low wind conditions. It is also impacted if unmanned aircraft system operates in the area or nearby. NASA is exploring opportunities where a variety of aircraft and their coordinated airspace management would improve the effectiveness of aerial firefighting. Dr. Kopardekar will discuss future aircraft requirements, approach for coordinated firefighting as well as a path towards improving effectiveness.

Aerial Fire Mitigation↗