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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Co-Adsorption of Carbon Dioxide on Zeolite 13X in the Presence of Preloaded Water

Background: Carbon Dioxide removal is a key aspect of Life Support for long-duration missions - Need to improve Mass, Power, and Volume of systems; Cabin air has three major constituents - Oxygen and Nitrogen, Carbon dioxide (CO2), Water Vapor; The mechanism for strong CO2 adsorption in zeolites (and many sorbents) is also the same mechanism for H2O - Water vapor is selectively adsorbed over CO2.

Cmarik, Gregory E.↗
NASA NTRS1973

Development of design information for molecular-sieve type regenerative CO2-removal systems

Experimental and analytic studies were conducted with molecular sieve sorbents to provide basic design information, and to develop a system design technique for regenerable CO2-removal systems for manned spacecraft. Single sorbate equilibrium data were obtained over a wide range of conditions for CO2, water, nitrogen, and oxygen on several molecular sieve and silica gel sorbents. The coadsorption of CO2 with water preloads, and with oxygen and nitrogen was experimentally evaluated. Mass-transfer, and some limited heat-transfer performance evaluations were accomplished under representative operating conditions, including the coadsorption of CO2 and water. CO2-removal system performance prediction capability was derived.

Wright, R. M.↗
NASA NTRS1991

Water resources and hydrology of Mars

The surface of Mars has been extensively modified by a large variety of water erosional and depositional processes. Although liquid water is presently unstable on the planet's surface, in its cold, hyperarid climate, there is abundant geomorphological evidence of past fluvial valley development multiple episodes of catastrophic flooding, periglacial landforms, ice-related permafrost, lake deposits, eroded impact craters and possible glacial landforms throughout much of Mars' geological history. The amount of water required to form such features is estimated to be equivalent to a planet-wide layer approximately 50 meters deep. Some of this water undoubtedly was removed from the planet by atmospheric escape processes, but much probably remains in the subsurface of Mars. Jakosky summarized the present partitioning of water on Mars, expressed as an average global depth, as follows: in the polar caps, 30 meters; in the megaregolith, 500 to 1000 meters; structurally bound in clays, 10 meters; and in high latitude regolith, a few meters. However, most of this water is probably in the form of ice, except in anomalous areas of possible near surface liquid water, and in regions where hydrothermal systems are still active. The best locations for prospecting are those areas where water or ice is sufficiently concentrated at shallow enough depths to make it feasible to pump out or mine.

Baker, V. R.↗
NASA NTRS1991

Computer simulation of water reclamation processors

The development of detailed simulation models of water reclamation processors based on the ASPEN PLUS simulation program is discussed. Individual models have been developed for vapor compression distillation, vapor phase catalytic ammonia removal, and supercritical water oxidation. These models are used for predicting the process behavior. Particular attention is given to methodology which is used to complete this work, and the insights which are gained by this type of model development.

Fisher, John W.↗
NASA NTRS2008

International Space Station USOS Potable Water Dispenser Development

The International Space Station (ISS) Russian Segment currently provides potable water dispensing capability for crewmember food and beverage rehydration. All ISS crewmembers rehydrate Russian and U.S. style food packages from this location. A new United States On-orbit Segment (USOS) Potable Water Dispenser (PWD) is under development. This unit will provide additional potable water dispensing capability to support an onorbit crew of six. The PWD is designed to provide incremental quantities of hot and ambient temperature potable water to U.S. style food packages. It will receive iodinated water from the Fuel Cell Water Bus in the U.S. Laboratory element. The unit will provide potable-quality water, including active removal of biocidal iodine prior to dispensing. A heater assembly contained within the unit will be able to supply up to 2.0 liters of hot water (65 to 93oC) every thirty minutes. This quantity will allow three to four crewmembers to rehydrate their food and beverages from this location during a single meal. The unit is designed to remain functional for up to ten years with replacement of limited life items such as filters. It will be the size of two stacked Shuttle Middeck lockers (approximately the size of two small suitcases) and integrated into a science payload rack in the U.S. Laboratory element. Providing potable-quality water at the proper temperature for food and beverage reconstitution is critical to maintaining crew health and well-being. The numerous engineering challenges as well as human factors and safety considerations during the concept, design, and prototyping are outlined in this paper.

Shaw, Laura A.↗
NASA NTRS1992

Shuttle Orbiter Environmental Control and Life Support System - Flight experience

This paper describes the overall design of the Shuttle Orbiter Environmental Control and Life Support System (ECLSS). The Orbiter ECLSS consists of six major subsystems which accomplish the functions of providing a habitable pressurized cabin atmosphere and removing gaseous contaminants, controlling the temperature of the cabin and vehicle components within acceptable ranges, providing fire detection and suppression capability, maintaining a supply of potable water, collecting and removing metabolic waste materials, and providing utilities and access for extravehicular activity. The operational experience is summarized for the 45 space flights accomplished to date during which the Orbiter ECLSS has been demonstrated to perform reliably, and has proved to have the flexibility to meet a variety of mission needs. Significant flight problems are described, along with the design or procedure changes which were implemented to resolve the problems.

Winkler, H. E.↗
NASA NTRS1988

A molecular dynamics study of chloride binding by the cryptand SC24

The capture of chloride from water by the tetraprotonated form of the spherical macrotricyclic molecule SC24 was studied using molecular dynamics simulation methods. This model ionophore represents a broad class of molecules which remove ions from water. Two binding sites for the chloride were found, one inside and one outside the ligand. These sites are separated by a potential energy barrier of approximately 20 kcal mol-1. The major contribution to this barrier comes from dehydration of the chloride. The large, unfavorable dehydration effect is compensated for by an increase in electrostatic attraction between the oppositely charged chloride and cryptand, and by energetically favorable rearrangements of water structure. Additional assistance in crossing the barrier and completing the dehydration of the ion is provided by the shift of three positively charged hydrogen atoms of the cryptand towards the chloride. This structural rigidity is partially responsible for its selectivity.

NASA Discipline Exobiology↗
NASA NTRSDate not supplied

ISS EVA80 EMU Water in the Helmet Failure and Associated Analytical Response

On March 23rd, 2022, during Extra-Vehicular Activity (EVA) 80 aboard the International Space Station (ISS) crew identified an 8-10-inch diameter thin film of water in the pressure bubble of the suit during repress. This launched an investigation to determine the cause of the water in the helmet as well as short- and long-term mitigation efforts to enable return to EVA as quickly as possible. The investigation analysis efforts in combination with hardware inspection and testing determined the most likely cause of the water in the helmet to be sublimator carryover as a result of high latent loading put on the system. In parallel with this investigation, efforts were being made to mitigate any future water in the helmet events. The short-term mitigation strategy developed is to install absorbent material in the pressure bubble to capture water as it enters the helmet before it can impact the astronauts. This hardware is referred to as the Helmet Absorption Band (HAB) and Helmet Absorption Pad – Extender (HAP-E). Longer-term mitigation strategies include a device to capture small water events before entering the helmet by installing a water capture system in the vent loop of the Extravehicular Mobility Unit (EMU). This effort is coined the T2 Water Capture System. Additionally, developing an on-orbit sublimator challenge test which will be able to verify sublimator performance before and after EVAs. The sublimator is the hardware which condenses water vapor and removes it from the vent loop, and this hardware is referred to as the EMU Moisture Injection Test System (EMITS). Based on the investigation and short-term water capture solutions the ISS Program decided to return to nominal EVAs on October 7, 2022. With the addition of the long-term mitigation strategies, the team hopes to be able to prevent any future water in the helmet events.

Veronica Lee Pizor↗
NASA NTRS2005

Condensing Heat Exchanger Concept Developed for Space Systems

The current system for moisture removal and humidity control for the space shuttles and the International Space Station uses a two-stage process. Water first condenses onto fins and is pulled through "slurper bars." These bars take in a two-phase mixture of air and water that is then separated by the rotary separator. A more efficient design would remove the water directly from the air without the need of an additional water separator downstream. For the Condensing Heat Exchanger for Space Systems (CHESS) project, researchers at the NASA Glenn Research Center in collaboration with NASA Johnson Space Center are designing a condensing heat exchanger that utilizes capillary forces to collect and remove water and that can operate in varying gravitational conditions including microgravity, lunar gravity, and Martian gravity.

Hasan, Mohammad M.↗
NASA NTRS1987

The relationship between water binding and desiccation tolerance in tissues

In an effort to define the nature of desiccation tolerance, a comparison of the water sorption characteristics was made between tissues that were resistant and tissues that were sensitive to desiccation. Water sorption isotherms were constructed for germinated and ungerminated soybean axes and also for fronds of several species of Polypodium with varying tolerance to dehydration. The strength of water binding was determined by van't Hoff as well as D'Arcy/Watt analyses of the isotherms at 5, 15, and/or 25 degrees C. Tissues which were sensitive to desiccation had a poor capacity to bind water tightly. Tightly bound water can be removed from soybean and pea seeds by equilibration at 35 degrees C over very low relative humidities; this results in a reduction in the viability of the seed. We suggest that region 1 water (i.e. water bound with very negative enthalpy values) is an important component of desiccation tolerance.

NASA Discipline Number 40-10↗
NASA NTRS2007

Space Suit Radiator Performance in Lunar and Mars Environments

During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut's metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment and the load from the electrical components. Although the sublimator hardware to reject this load weighs only 3.48 lbs, an additional eight pounds of water are loaded into the unit of which about six to eight are sublimated and lost; this is the single largest expendable during an eight-hour EVA. Using a radiator to reject heat from the Astronaut during an EVA, we can significantly reduce the amount of expendable water consumed by the sublimator. Last year we reported on the design and initial operational assessment tests of our novel radiator designated the Radiator And Freeze Tolerant heat eXchanger (RAFT-X). Herein, we report on tests conducted in the NASA Johnson Space Center Chamber E Thermal Vacuum Test Facility. Up to 800 Btu/h of heat were rejected in lunar and Mars environments with temperatures as cold as -150 F. Tilting the radiator did not cause an observable loss in performance. The RAFT-X endured freeze / thaw cycles and in fact, the heat exchanger was completely frozen three times without any apparent damage to the unit. We were also able to operate the heat exchanger in a partially frozen configuration to throttle the heat rejection rate from 530 Btu/h at low water flow rate down to 300 Btu/h. Finally, the deliberate loss of a single loop heat pipe only degraded the heat rejection performance by about 2 to 5%.

Nabity, James↗
NASA NTRS2007

Space Suit Radiator Performance in Lunar and Mars Environments

During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut's metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment and the load from the electrical components. Although the sublimator hardware to reject this load weighs only 3.48 lbs, an additional eight pounds of water are loaded into the unit of which about six to eight are sublimated and lost; this is the single largest expendable during an eight-hour EVA. Using a radiator to reject heat from the Astronaut during an EVA, we can significantly reduce the amount of expendable water consumed by the sublimator. Last year we reported on the design and initial operational assessment tests of our novel radiator designated the Radiator And Freeze Tolerant heat eXchanger (RAFT-X). Herein, we report on tests conducted in the NASA Johnson Space Center Chamber E Thermal Vacuum Test Facility. Up to 800 Btu/h of heat were rejected in lunar and Mars environments with temperatures as cold as 150 F. Tilting the radiator did not cause an observable loss in performance. The RAFT-X endured freeze/thaw cycles and in fact, the heat exchanger was completely frozen three times without any apparent damage to the unit. We were also able to operate the heat exchanger in a partially frozen configuration to throttle the heat rejection rate from 530 Btu/h at low water flow rate down to 300 Btu/h. Finally, the deliberate loss of a single loop heat pipe only degraded the heat rejection performance by about 2 to 5%.

Paul, Heather↗
NASA NTRS2005

Space Suit Radiator Performance in Lunar and Mars Environments

During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut's metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment and the load from the electrical components. Although the sublimator hardware to reject this load weighs only 1.58 kg (3.48 lbm), an additional 3.6 kg (8 lbm) of water are loaded into the unit, most of which is sublimated and lost to thus become the single largest expendable during an eight hour EVA. We can significantly reduce the amount of expendable water consumed in the sublimator by using a radiator to reject heat from the Astronaut during an EVA. Last year we reported on the design and initial operational assessment tests of our novel radiator designated the Radiator And Freeze Tolerant heat eXchanger (RAFT-X). Herein, we report on tests conducted in the NASA Johnson Space Center Chamber E Thermal Vacuum Test Facility. Up to 260 W (900 Btu/h) of heat were rejected in Lunar and Mars environments with temperatures as cold as -170 C (- 275 F). Further, the RAFT-X endured several freeze / thaw cycles and in fact, the heat exchanger was completely frozen three times without any apparent damage to the unit.

Nabity, James↗
NASA NTRS2008

A Freezable Heat Exchanger for Space Suit Radiator Systems

During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut s metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment and the load from the electrical components. Although the sublimator hardware to reject this load weighs only 1.58 kg (3.48 lbm), an additional 3.6 kg (8 lbm) of water are loaded into the unit, most of which is sublimated and lost to space, thus becoming the single largest expendable during an eight-hour EVA. Using a radiator to reject heat from the astronaut during an EVA can reduce the amount of expendable water consumed in the sublimator. Radiators have no moving parts and are thus highly reliable. Past freezable radiators have been too heavy, but the weight can be greatly reduced by placing a small and freeze tolerant heat exchanger between the astronaut and radiator, instead of making the very large radiator freeze tolerant. Therefore, the key technological innovation to improve space suit radiator performance was the development of a lightweight and freezable heat exchanger that accommodates the variable heat load generated by the astronaut. Herein, we present the heat transfer performance of a newly designed heat exchanger that endured several freeze / thaw cycles without any apparent damage. The heat exchanger was also able to continuously turn down or turn up the heat rejection to follow the variable load.

Nabity, James A.↗
NASA NTRS2019

Improving Brightness Temperature Measurements near Coastal Areas for SMAP

The Soil Moisture Active Passive (SMAP) mission is designed to acquire L-band radiometer measurements for the estimation of soil moisture with 0.04 m3/m3 volumetric accuracy in the top 5 cm for vegetation with water content of less than 5 kg/m2. In regions near the coast or near inland bodies of water, the signal measured by the SMAP radiometer contains emissions from land and water, resulting in errors in the soil moisture estimation. In this paper, the effort to extract the brightness temperature (TB) according to the land fraction or water fraction (depending on the center of the footprint location) from the affected SMAP measurements was addressed. A single pixel correction algorithm was applied and its performance was evaluated over simulated data. A data-driven approach for the estimation of land and water TB for data correction was developed. The correction algorithm was then applied to real data and its performance was assessed over the SMAP soil moisture retrievals. We showed that the single pixel algorithm is an effective and computationally efficient algorithm for removing land or water TB contamination from the SMAP data.

Julian Chaubell↗
NASA NTRSDate not supplied

Modeled Impacts of LULC and Climate Change Predictions on Water Quality in Belize

Land use and land cover (LULC) change can have detrimental effects on water quality. In Belize, agricultural expansion creates the risk of increased sediment load and excess nutrients in runoff water, while deforestation removes potential infiltration sites for this outflow. Climate change and evolving precipitation rates can intensify the quantity of runoff, further enabling the flow of sediments and excess nutrients out to the lagoon surrounding the Belize Barrier Reef Reserve System (BBRRS). This study estimated future water quality in Belize by projecting LULC change through 2090 across Belize’s major watersheds based on observed trends from 2008-2018. Those LULC projections were subsequently combined with soil type data, elevation, and precipitation rates into a hydrologic model to produce runoff estimates as a proxy for water quality. The two Coupled Model Intercomparison Project phase 6 (CMIP-6) scenarios employed in the study represented bookend climate change scenarios, and both predicted lower precipitation rates in Belize over the next century due to climate change. When holding LULC change constant, these climate scenarios projected a decrease in runoff, suggesting a positive relationship between precipitation and runoff. The southern watersheds in particular are projected to experience greater decreases in annual rainfall and runoff by 2090. When holding climate constant, runoff increased by approximately 2.8% in the Conservation-focused LULC scenario by 2090, which was 28% lower than the Business as Usual scenario and 42% lower than the Development scenario.

water resources↗
NASA NTRS1978

Aqueous vinylidene fluoride polymer coating composition

A water-based coating composition which may be air dried to form durable, fire resistant coatings includes dispersed vinylidene fluoride polymer particles, emulsified liquid epoxy resin and a dissolved emulsifying agent for said epoxy resin which agent is also capable of rapidly curing the epoxy resin upon removal of the water from the composition.

Bartoszek, Edward J.↗