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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 127 records · Page 7

Growth Chambers on the International Space Station for Large Plants

The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED lighting, and those capabilities continue to expand. The 'Veggie' vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of horticultural crops. It was designed for low power usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nm), blue, (455 nm) and green (530 nm) LEDs. Interfacing with the light cap is an extendable bellows/baseplate for enclosing the plant canopy. A second large plant growth chamber, the Advanced Plant Habitat (APH), is will fly to the ISS in 2017. APH will be a fully controllable environment for high-quality plant physiological research. APH will control light (quality, level, and timing), temperature, CO2, relative humidity, and irrigation, while scrubbing any cabin or plant-derived ethylene and other volatile organic compounds. Additional capabilities include sensing of leaf temperature and root zone moisture, root zone temperature, and oxygen concentration. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs (4100K). There will be several internal cameras (visible and IR) to monitor and record plant growth and operations. Veggie and APH are available for research proposals.

Advanced Plant Habitat↗

Growth Chambers on the International Space Station for Large Plants

The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED (Light Emitting Diodes) lighting, and those capabilities continue to expand. The Veggie vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of horticultural crops. It was designed for low power usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nanometers), blue, (455 nanometers) and green (530 nanometers) LEDs. Interfacing with the light cap is an extendable bellowsbaseplate for enclosing the plant canopy. A second large plant growth chamber, the Advanced Plant Habitat (APH), is will fly to the ISS in 2017. APH will be a fully controllable environment for high-quality plant physiological research. APH will control light (quality, level, and timing), temperature, CO2, relative humidity, and irrigation, while scrubbing any cabin or plant-derived ethylene and other volatile organic compounds. Additional capabilities include sensing of leaf temperature and root zone moisture, root zone temperature, and oxygen concentration. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs (4100K). There will be several internal cameras (visible and IR) to monitor and record plant growth and operations. Veggie and APH are available for research proposals.

Veggie↗

Aerodynamic behavior of the Viking entry vehicle - Ground test and flight results

An extensive series of tests of the Viking entry vehicle flying in pure CO2 was conducted in a ballistic range at Ames Research Center. The primary purpose of these tests was to calibrate the aerodynamic lift and drag characteristics in order to allow the density, pressure, and temperature profiles of the Martian atmosphere to be determined from onboard instrumentation carried on Viking. Both the Viking 1 and Viking 2 entry vehicles performed flawlessly during entry and descent, and the atmosphere structure was deduced to an altitude of about 120 km. A description is given of the ballistic range tests and of the aerodynamic behavior of the full scale entry vehicles during entry into the Martian atmosphere. Some comparisons between ground test and flight results are shown.

Kirk, D. B.↗

Heat flow vs. atmospheric greenhouse on early Mars

Researchers derived a quantitative relationship between the effectiveness of an atmospheric greenhouse and internal heat flow in producing the morphological differences between earlier and later Martian terrains. The derivation is based on relationships previously derived by other researchers. The reasoning may be stated as follows: the CO2 mean residence time in the Martian atmosphere is almost certainly much shorter than the total time span over which early climate differences are thought to have been sustained. Therefore, recycling of previously degassed CO2 quickly becomes more important than the ongoing supply of juvenile CO2. If so, then the atmospheric CO2 pressure, and thereby the surface temperature, may be approximated mathematically as a function of the total degassed CO2 in the atmosphere plus buried material and the ratio of the atmospheric and regolith mean residence times. The latter ratio can also be expressed as a function of heat flow. Hence, it follows that the surface temperature may be expressed as a function of heat flow and the total amount of available CO2. However, the depth to the water table can simultaneously be expressed as a function of heat flow and the surface temperature (the boundary condition). Therefore, for any given values of total available CO2 and regolith conductivity, there exist coupled independent equations which relate heat flow, surface temperature, and the depth to the water table. This means we can now derive simultaneous values of surface temperature and the depth of the water table for any value of the heat flow. The derived relationship is used to evaluate the relative importance of the atmospheric greenhouse effect and the internal regolith thermal gradient in producing morphological changes for any value of the heat flow, and to assess the absolute importance of each of the values of the heat flow which are thought to be reasonable on independent geophysical grounds.

Fanale, F. P.↗

Overview of NASA's Propulsion 21 Effort

Propulsion 21 technologies contribute to reducing CO2 and NO(x) emissions and noise. Integrated Government/Industry/University research efforts have produced promising initial technical results. Graduate students from 5 partnering universities will benefit from this collaborative research--> educating the future engineering workforce. Phase 2 Efforts scheduled to be completed 3QFY06.

Long-Davis, Mary Jo↗

Acute and Chronic Exposure to CO2 in Space Flight

Spacecraft and space stations, similar to other habitable confined spaces such as submarines, need to provide a breathable atmosphere for their inhabitants. The inevitable production of CO2 during respiration necessitates life support systems that "scrub" the atmosphere and lower CO2 levels. Due to operational limitations associated with space flight (limited mass, volume, power, and consumables) CO2 is not scrubbed down to its terrestrial equivalent of 0.03% CO2 (ppCO2 of 0.23 mmHg), but is kept below 0.7% (ppCO2 of 5.3 mmHg), a level established in NASA s 180-day mission Spacecraft Maximum Allowable Concentration (SMAC) to be safe and unlikely to cause symptoms. Reports of space flight crewmembers becoming symptomatic with headaches, fatigue, and malaise at levels below those known to cause such symptoms terrestrially has prompted studies measuring the levels of CO2 on both the space shuttle and the space station. Data from cabin atmosphere sampling were collected on space shuttle missions STS-113, STS-122, STS-123, and International Space Station Expeditions 12-15 and 17, and the measured CO2 levels were then correlated to symptoms reported by the crew. The results indicate that a correlation exists between CO2 levels and symptomatology, however causality cannot be established at this time. While the short-term effects of elevated CO2 exposure are well known terrestrially, less is known regarding potential long-term effects of prolonged exposure to a CO2-rich environment or how the physiological changes caused by microgravity may interact with such exposures. Other challenges include limitations in the CO2 monitors used, lack of convection in the microgravity environment, and formation of localized CO2 pockets. As it is unclear if the unique environment of space increases sensitivity to CO2 or if other confounding factors are present, further research is planned to elucidate these points. At the same time, efforts are underway to update the SMAC to a lower level

Alexander, D.↗

Experimental Configuration and Preliminary Results of Testing a Rapid Cycle Adsorption Pump for Martian CO2 Acquisition

Temperature-swing adsorption pumps have been proposed as a method of acquiring and compressing Martian atmospheric CO2 for downstream processing. Most industrial applications and previous research targeted at space in-situ resource utilization (ISRU) utilize long (~hours) temperature swing periods, typically limited by the ability to transfer heat from a naturally insulating sorbent bed. A rapid cycle adsorption pump (RCAP) would reduce these periods to minutes, in the hope of increasing overall throughput. This paper details the design and preliminary experimental results from testing an RCAP in a simulated Martian environment. The test configuration features a central, liquid-cooled and heated heat transfer plate surrounded by symmetrical rectangular sorbent beds. Various bed thicknesses and commercially available Zeolite 13X sorbent particle sizes are evaluated to both determine performance and provide data for a parallel modeling effort. Discussions of multi-stage configurations and methods of boosting bed conductivity are included.

Berg, Jared↗

Experimental Design and Preliminary Analysis of a Mars CO2 Rapid Cycle Adsorption Pump

Temperature-swing adsorption pumps have been proposed as a method of acquiring and compressing Martian atmospheric CO2 for downstream processing. Most industrial applications and previous research targeted at space in-situ resource utilization (ISRU) utilize long (~hours) temperature swing periods, typically limited by the ability to transfer heat from a naturally insulating sorbent bed. A rapid cycle adsorption pump (RCAP) would reduce these periods to minutes, in the hope of increasing overall throughput. This paper details the design and preliminary experimental results from testing an RCAP in a simulated Martian environment. The test configuration features a central, liquid-cooled and heated heat transfer plate surrounded by symmetrical rectangular sorbent beds. Various bed thicknesses and commercially available Zeolite 13X sorbent particle sizes are evaluated to both determine performance and provide data for a parallel modeling effort. Discussions of multi-stage configurations and methods of boosting bed conductivity are included.

Rapid Cycle Adsorption↗

Cirrus properties deduced from CO2 lidar observations of zenith-enhanced backscatter from oriented crystals

Many lidar researchers have occasionally observed zenith-enhanced backscatter (ZEB) from middle and high clouds. The ZEB signature consists of strong backscatter when the lidar is pointed directly at zenith and a dramatic decline in backscatter as the zenith angle dips slightly off zenith. Mirror-like reflection from horizontal facets of oriented crystals (especially plates) is generally accepted as the cause. It was found during a 3-year observation program that approximately 50 percent of ice clouds had ZEB, regardless of cloud height. The orientation of crystals and the ZEB they cause are important to study and understand for several reasons. First, radiative transfer in clouds with oriented crystals is different than if the same particles were randomly oriented. Second, crystal growth depends partly on the orientation of the particles. Third, ZEB measurements may provide useful information about cirrus microphysical and radiative properties. Finally, the remarkable effect of ZEB on lidar signals should be understood in order to properly interpret lidar data.

Eberhard, Wynn L.↗

Plant Habitat (PH)

The International Space Station (ISS) will soon have a platform for conducting fundamental research of Large Plants. Plant Habitat (PH) is designed to be a fully controllable environment for high-quality plant physiological research. PH will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional capabilities include leaf temperature and root zone moisture and oxygen sensing. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs. There will be several internal cameras (visible and IR) to monitor and record plant growth and operations.

Advanced Plant Habitat↗

Airborne/Space-Based Doppler Lidar Wind Sounders Sampling the PBL and Other Regions of Significant Beta and U Inhomogeneities

This final report covers the period from April 1994 through March 1998. The proposed research was organized under four main tasks. Those tasks were: (1) Investigate the vertical and horizontal velocity structures within and adjacent to thin and subvisual cirrus; (2) Investigate the lowest 1 km of the PBL and develop algorithms for processing pulsed Doppler lidar data obtained from single shots into regions of significant inhomogeneities in Beta and U; (3) Participate in OSSEs including those designed to establish shot density requirements for meso-gamma scale phenomena with quasi-persistent locations (e.g., jets, leewaves, tropical storms); and (4) Participate in the planning and execution of an airborne mission to measure winds with a pulsed CO2 Doppler lidar. Over the four year period of this research contract, work on all four tasks has yielded significant results which have led to 38 professional presentations (conferences and publications) and have been folded into the science justification for an approved NASA space mission, SPARCLE (SPAce Readiness Coherent Lidar Experiment), in 2001. Also this research has, through Task 4, led to a funded proposal to work directly on a NASA field campaign, CAMEX III, in which an airborne Doppler wind lidar will be used to investigate the cloud-free circulations near tropical storms. Monthly progress reports required under this contract are on file. This final report will highlight major accomplishments, including some that were not foreseen in the original proposal. The presentation of this final report includes this written document as well as material that is better presented via the internet (web pages). There is heavy reference to appended papers and documents. Thus, the main body of the report will serve to summarize the key efforts and findings.

Emmitt, Dave↗

New Crop Selection

For extended space flight, reliable food supplies are a necessity. Most of the food products consumed by astronauts today are stored for flight via freeze drying. Fresh food is needed to supplement known national deficiencies in the stored food diet (Cooper et al.). This is so because stored foods can lose nutritional value. Fresh food is the answer to the nutritional demands of space flight. Kennedy Space Center's Utilization and Life Sciences Office (UB-A), under the Exploration Research and Technology Program (UB), conducts research on plant growth and development under International Space Station (ISS) conditions. UB-A analyzes the growth responses of leafy greens in microgravity and through the manipulation of environmental conditions (CO2 levels, light intensity, relative humidity, and water delivery). By manipulating growing conditions researchers can optimize food production using minimal/restricted resources. The New Crop Selection experiments are testing the suitability of leafy crops to ISS conditions. Results from this study showed that 'Dragoon' Lettuce and 'Red Russian' Kale have the largest fresh mass.

Bhuiyan, Ruqayah H.↗

Is CO2 capable to keeping early Mars warm?

One of the goals of NASA's Exobiology Research Program is to determine whether life exists today on Mars (unlikely) or whether it might have existed there at some time in the past (more likely). Speculation about extinct life is driven by the observation of channels on the Martian surface, thought to indicate the past presence of liquid water and, hence, the existence of a warmer climate. Current thinking suggests that such a climate could have been maintained if early Mars had a dense CO2 atmosphere with a surface pressure of 1 to 5 bars. One of the phenomena that Martian climate modelers have not looked at very carefully is the process of CO2 condensation. Reexamination of some of my own calculations indicates that condensation should occur at high altitudes in some high-CO2, Martian atmospheres, particularly those in which the solar constant is set to its initial main sequence value (about 70 percent of present. CO2 condensation should affect the surface temperature in two ways: (1) if it occurs in the convective lower atmosphere, condensation will reduce the magnitude of the greenhouse effect by decreasing the lapse rate; and (2) condensation at any altitude will produce clouds, which can either warm or cool the climate depending on their altitude and optical depth. Preliminary calculations with a 1-D, radiative-convective climate model indicate that the lapse rate change is substantial for low solar luminosity models. Other aspects of this study are discussed.

Kasting, J. F.↗

Evaluation of Ionic Liquids for Closed Air Revitalization

This document is the final report resulting from the work conducted by undergraduate students at the University of South Alabama during the 2018/2019 academic year and was prepared by the undergraduate students. As NASA pushes the boundaries further into space, the current technologies within the various life support systems must be improved upon. One such improvement is needed to the current air revitalization systems, specifically sorbents that can capture CO2 more effectively from enclosed habitats. Ionic liquids (ILs) have been considered as absorbents for flue gas, but little research has been done to test the ability of ILs at ambient pressures and relatively low concentration of CO2. The experiment outlined below utilizes the task-specific ionic liquid, tetramethylammonium taurinate (TMN), in a commercial off the shelf absorption system to capture CO2. The CO2 stream is combined with nitrogen to produce an inlet gas concentration relevant to close air revitalization applications. At an inlet gas flow with a CO2 partial pressure of 3.8 torr the system was capable of removing just under 97% of the inlet CO2. The concentration of CO2 in the outlet stream, partial pressure 0.16 torr, was less than that of atmospheric air. The duty required to separate the absorbed gas from the ionic liquid as well to cool the ionic liquid to be reintroduced to the column were acquired utilizing laboratory cooling/heating baths. These results show that TMN may be an efficient candidate for consideration in closed air revitalization.

Duck, Gerald↗

Partitioning of ocean and land uptake of CO2 as inferred by delta C-13 measurements from the NOAA Climate Monitoring and Diagnostics Laboratory Global Air Sampling Network

Using delta C-13 measurements in atmospheric CO2 from a cooperative global air sampling network, we determined the partitioning of the net uptake of CO2 between ocean and land as a function of latitude and time. The majority of delta C-13 measurements were made at the Institute of Arctic and Alpine Research (INSTAAR) of the University of Colorado. We perform an inverse deconvolution of both CO2 and delta C-13 observations, using a two-dimensional model of atmospheric transport. Also, the discrimination against C-13 by plant photosynthesis, as a function of latitude and time, is calculated from global runs of the simple biosphere (SiB) model. Uncertainty due to the longitudinal structure of the data, which is not represented by the model, is studied through a bootstrap analysis by adding and omitting measurement sites. The resulting error estimates for our inferred sources and sinks are of the order of 1 GTC (1 GTC = 10(exp 15) gC). Such error bars do not reflect potential systematic errors arising from our estimates of the isotopic disequilibria between the atmosphere and the oceans and biosphere, which are estimated in a separate sensitivity analysis. With respect to global totals for 1992 we found that 3.2 GTC of carbon dissolved into the ocean and that 1.5 GTC were sequestered by land ecosystems. Northern hemisphere ocean gyres north of 15 deg N absorbed 2.7 GTC. The equatorial oceans between 10 deg S and 10 deg N were a net source to the atmosphere of 0.9 GTC. We obtained a sink of 1.6 GTC in southern ocean gyres south of 20 deg S, although the deconvolution is poorly constrained by sparse data coverage at high southern latitudes. The seasonal uptake of CO2 in the northern gyres appears to be correlated with a bloom of phytoplankton in surface waters. On land, northern temperate and boreal ecosystems between 35 deg N and 65 deg N were found to be a major sink of CO2 in 1992, as large as 3.5 GTC. Northern tropical ecosystems (equator-30 deg N) appear to be a net source to the source to the atmosphere of 2 GTC which could reflect biomass burning. A small sink, 0.3 GTC, was inferred for southern tropical ecosystems (30 deg S-equator).

Ciais, Philippe↗

Carbon Dioxide Control System for a Mars Space Suit Life Support System

Carbon dioxide (CO2) control during Extravehicular Activities (EVAs) on Mars will be challenging. Lithium hydroxide (LiOH) canisters have impractical logistics penalties, and regenerable metal oxide (MetOx) canisters weigh too much. Cycling bed systems and permeable membranes that are regenerable in space vacuum cannot vent on Mars due to the high partial pressure of CO2 in the atmosphere. Although sweep gas regeneration is under investigation, the feasibility, logistics penalties, and failure modes associated with this technique have not been fully determined. TDA Research, Inc. is developing a durable, high-capacity regenerable adsorbent that can remove CO2 from the space suit ventilation loop. The system design allows sorbent regeneration at or above 6 torr, eliminating the potential for Martian atmosphere to leak into the regeneration bed and into the ventilation loop. Regeneration during EVA eliminates the consumable requirement related to the use of LiOH canisters and the mission duration limitations imposed by MetOx system. The concept minimizes the amount of consumable to be brought from Earth and makes the mission more affordable, while providing great operational flexibility during EVA. The feasibility of the concept has been demonstrated in a series of bench-scale experiments and a preliminary system analysis. Results indicate that sorbent regeneration can be accomplished by applying a 14 C temperature swing, while regenerating at 13 torr (well above the Martian atmospheric pressure), withstanding over 1,000 adsorption/regeneration cycles. This paper presents the latest results from these sorbent and system development efforts.

Alptekin, Gokhan↗

Carbon Dioxide Control System for a Mars Space Suit Life Support System

Carbon dioxide (CO2) control during Extravehicular Activities (EVAs) on Mars will be challenging. Lithium hydroxide (LiOH) canisters have impractical logistics penalties, and regenerable metal oxide (MetOx) canisters weigh too much. Cycling bed systems and permeable membranes that are regenerable in space vacuum cannot vent on Mars due to the high partial pressure of CO2 in the atmosphere. Although sweep gas regeneration is under investigation, the feasibility, logistics penalties, and failure modes associated with this technique have not been fully determined. TDA Research, Inc. is developing a durable, high-capacity regenerable adsorbent that can remove CO2 from the space suit ventilation loop. The system design allows sorbent regeneration at or above 6 torr, eliminating the potential for Martian atmosphere to leak into the regeneration bed and into the ventilation loop. Regeneration during EVA minimizes the amount of consumables to be brought from Earth and makes the mission more affordable, while providing great operational flexibility during EVA. The feasibility of the concept has been demonstrated in a series of bench-scale experiments and a preliminary system analysis. This paper presents the latest results from these sorbent and system development efforts.

Alptekin, Gokhan↗

Characterization of CO 4th Positive Radiation in CO2-Ar Mixtures

This paper presents measurements and simulations of CO 4th Positive spectra obtained in NASA Ames Research Center's Electric Arc Shock Tube (EAST) and CentraleSupelec's Plasma Torch. The experiments were aimed at measuring optically thin emission for the main band features of CO 4th Positive by using test gas mixtures of CO2 and Ar. By using mixtures of CO2 and Ar, the temperature of the flow (and consequently black-body curve) is increased compared to using pure CO2 (or CO2 / N2 mixtures). This temperature increase allows for emission spectroscopy of features that would nominally be black-body limited for conditions relevant to Mars entry. The CO 4th Positive system is the focus of this study as it accounts for a large percentage of the emitted radiation for Martian entry, and also due to the difficulties of obtaining experimental validation data due to the emission appearing in the Vacuum Ultraviolet (VUV) spectral range. The focus of this paper is to provide a comprehensive comparison between the EAST and plasma torch data along with various CO 4th Positive databases available in the literature. Previously reported VUV CO2 / N2 EAST data required a larger temperature than would be predicted based upon equilibrium shock relations. The need for the temperature increase implies that the EAST experiment did not fully equilibrate. Thus, it is presumed that the EAST data did not obtain an equilibrium condition. The plasma torch data, on the other hand, is very consistent with equilibrium assumptions. Thus, the equilibrium data obtained in the plasma torch is utilized to construct the CO 4th Positive emission model, which is then applied to the EAST data with a non-equilibrium interpretation.

A. M. Brandis↗