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NASA NTRS2016

Kennedy Space Center Five Year Sustainability Plan

The Federal Government is committed to following sustainable principles. At its heart, sustainability integrates environmental, societal and economic solutions for present needs without compromising the ability of future generations to meet their needs. Building upon its pledge towards environmental stewardship, the Administration generated a vision of sustainability spanning ten goals mandated within Executive Order (EO) 13693, Planning for Federal Sustainability in the Next Decade. In November 2015, the National Aeronautics and Space Administration (NASA) responded to this EO by incorporating it into a new release of the NASA Strategic Sustainability Performance Plan (SSPP). The SSPP recognizes the importance of aligning environmental practices in a manner that preserves, enhances and strengthens NASA's ability to perform its mission indefinitely. The Kennedy Space Center (KSC) is following suit with KSC's Sustainability Plan (SP) by promoting, maintaining and pioneering green practices in all aspects of our mission. KSC's SP recognizes that the best sustainable solutions use an interdisciplinary, collaborative approach spanning civil servant and contractor personnel from across the Center. This approach relies on the participation of all employees to develop and implement sustainability endeavors connected with the following ten goals: Reduce greenhouse gas (GHG) emissions. Design, build and maintain sustainable buildings, facilities and infrastructure. Leverage clean and renewable energy. Increase water conservation. Improve fleet and vehicle efficiency and management. Purchase sustainable products and services. Minimize waste and prevent pollution. Implement performance contracts for Federal buildings. Manage electronic equipment and data centers responsibly. Pursue climate change resilience. The KSC SP details the strategies and actions that address the following objectives: Reduce Center costs. center dot Increase energy and water efficiencies. Promote smart buying practices. Increase reuse and recycling while decreasing waste. Benefit the community. Meet or exceed the EO and NASA SSPP sustainability goals.

Sustainability↗

NASA NTRS2009

Using Microwaves for Extracting Water from the Moon

Twenty years ago, the Lunar Prospector remote sensing satellite provided evidence of relatively large hydrogen concentrations at the lunar poles and in particular concentrated in permanently shadowed craters. The scientific hypothesis is that the hydrogen is in the form of cryo-trapped water just under the surface of the soil. If true this would mean that an average of about 2% water ice is mixed with the lunar soil existing in the form of ice at cryogenic temperatures. For 5 years we have been investigating the use of microwaves for the processing of lunar soil. One of the early uses could be to use microwave energy to extract volatiles and in particular water from the lunar permafrost. Prototype experiments have shown that microwave energy at 2.45 GHz, as in consumer microwave ovens, will couple with and heat cryogenically cooled lunar soil permafrost simulant, resulting in the rapid sublimation of water vapor into the vacuum chamber. The water vapor has been collected on a cryogenic cold trap with high efficiency. The primary advantage of microwave processing is that the volatiles can be extracted in situ. Excavation would not be required. Microwave frequency dielectric property measurements are being made of different lunar soil simulants and plans are to measure Apollo lunar soil at different frequencies and over a range of temperatures. The materials properties are being used to evaluate the heating of lunar soil and develop COMSOL models that can be used to evaluate different microwave extraction scenarios. With COMSOL the heating from cryogenic temperatures can be calculated and COMSOL will permit temperature dependent materials properties to be used during the heating process. Calculations at different microwave frequencies will allow the evaluation of the type of hardware that would be needed to most efficiently extract the water and other volatiles.

Ethridge, Edwin C.↗

NASA NTRS2009

Using Microwaves for Extracting Water from the Moon

This disk contains a video that accompanies the talk. Twenty years ago, the Lunar Prospector remote sensing satellite provided evidence of relatively large hydrogen concentrations at the lunar poles and in particular concentrated in permanently shadowed craters. The scientific hypothesis is that the hydrogen is in the form of cryo-trapped water just under the surface of the soil. If true this would mean that an average of about 2% water ice is mixed with the lunar soil existing in the form of ice at cryogenic temperatures. For 5 years we have been investigating the use of microwaves for the processing of lunar soil. One of the early uses could be to use microwave energy to extract volatiles and in particular water from the lunar permafrost. Prototype experiments have shown that microwave energy at 2.45 GHz, as in consumer microwave ovens, will couple with and heat cryogenically cooled lunar soil permafrost simulant, resulting in the rapid sublimation of water vapor into the vacuum chamber. The water vapor has been collected on a cryogenic cold trap with high efficiency. The primary advantage of microwave processing is that the volatiles can be extracted in situ. Excavation would not be required. Microwave frequency dielectric property measurements are being made of different lunar soil simulants and plans are to measure Apollo lunar soil at different frequencies and over a range of temperatures. The materials properties are being used to evaluate the heating of lunar soil and develop COMSOL models that can be used to evaluate different microwave extraction scenarios. With COMSOL the heating from cryogenic temperatures can be calculated and COMSOL will permit temperature dependent materials properties to be used during the heating process. Calculations at different microwave frequencies will allow the evaluation of the type of hardware that would be needed to most efficiently extract the water and other volatiles. The video shows the partial results of the COMSOL modeling.

Ethridge, Edwin C.↗

NASA NTRS2009

Using Microwaves for Extracting Water from the Moon

This disk contains 2 videos that accompanies the talk. Twenty years ago, the Lunar Prospector remote sensing satellite provided evidence of relatively large hydrogen concentrations at the lunar poles and in particular concentrated in permanently shadowed craters. The scientific hypothesis is that the hydrogen is in the form of cryo-trapped water just under the surface of the soil. If true this would mean that an average of about 2% water ice is mixed with the lunar soil existing in the form of ice at cryogenic temperatures. For 5 years we have been investigating the use of microwaves for the processing of lunar soil. One of the early uses could be to use microwave energy to extract volatiles and in particular water from the lunar permafrost. Prototype experiments have shown that microwave energy at 2.45 GHz, as in consumer microwave ovens, will couple with and heat cryogenically cooled lunar soil permafrost simulant, resulting in the rapid sublimation of water vapor into the vacuum chamber. The water vapor has been collected on a cryogenic cold trap with high efficiency. The primary advantage of microwave processing is that the volatiles can be extracted in situ. Excavation would not be required. Microwave frequency dielectric property measurements are being made of different lunar soil simulants and plans are to measure Apollo lunar soil at different frequencies and over a range of temperatures. The materials properties are being used to evaluate the heating of lunar soil and develop COMSOL models that can be used to evaluate different microwave extraction scenarios. With COMSOL the heating from cryogenic temperatures can be calculated and COMSOL will permit temperature dependent materials properties to be used during the heating process. Calculations at different microwave frequencies will allow the evaluation of the type of hardware that would be needed to most efficiently extract the water and other volatiles. The 1st video shows the results of the COMSOL models. The second video shows brief views of the lunar surface.

Ethridge, Edwin C.↗

NASA NTRS2017

NIR-Driven Moist Upper Atmospheres of Synchronously Rotating Temperate Terrestrial Exoplanets

H2O is a key molecule in characterizing atmospheres of temperate terrestrial planets, and observations of transmission spectra are expected to play a primary role in detecting its signatures in the near future. The detectability of H2O absorption features in transmission spectra depends on the abundance of water vapor in the upper part of the atmosphere. We study the three-dimensional distribution of atmospheric H2O for synchronously rotating Earth-sized aquaplanets using the general circulation model (GCM) ROCKE-3D, and examine the effects of total incident flux and stellar spectral type. We observe a more gentle increase of the water vapor mixing ratio in response to increased incident flux than one-dimensional models suggest, in qualitative agreement with the climate-stabilizing effect of clouds around the substellar point previously observed in GCMs applied to synchronously rotating planets. However, the water vapor mixing ratio in the upper atmosphere starts to increase while the surface temperature is still moderate. This is explained by the circulation in the upper atmosphere being driven by the radiative heating due to absorption by water vapor and cloud particles, causing efficient vertical transport of water vapor. Consistently, the water vapor mixing ratio is found to be well-correlated with the near-infrared portion of the incident flux. We also simulate transmission spectra based on the GCM outputs, and show that for the more highly irradiated planets, the H2O signatures may be strengthened by a factor of a few, loosening the observational demands for a H2O detection.

Fujii, Yuka↗

NASA NTRS2016

Development of Advanced ISS-WPA Catalysts for Organic Oxidation at Reduced Pressure/Temperature

The Water Processor Assembly (WPA) at International Space Station (ISS) processes a waste stream via multi-filtration beds, where inorganic and non-volatile organic contaminants are removed, and a catalytic reactor, where low molecular weight organics not removed by the adsorption process are oxidized at elevated pressure in the presence of oxygen and elevated temperature above the normal water boiling point. Operation at an elevated pressure requires a more complex system design compared to a reactor that could operate at ambient pressure. However, catalysts currently available have insufficient activity to achieve complete oxidation of the organic load at a temperature less than the water boiling point and ambient pressure. Therefore, it is highly desirable to develop a more active and efficient catalyst at ambient pressure and a moderate temperature that is less than water boiling temperature. This paper describes our efforts in developing high efficiency water processing catalysts. Different catalyst support structures and coating metals were investigated in subscale reactors and results were compared against the flight WPA catalyst. Detailed improvements achieved on alternate metal catalysts at ambient pressure and 200 F will also be presented in the paper.

Yu, Ping↗

NASA NTRSDate not supplied

Derivation and Testing of Consumptive Water Use Fraction for Specialty Crops

The Crop Consumptive Use Fraction (CCUF) expresses beneficial water use in the form of seasonal evapotranspiration of applied water (ETAW), relative to total irrigation volume. The metric is an indicator of the efficiency of agricultural water use and is a recommended component for preparation of agricultural water management plans in California. An FAO-56 based web application has been developed to facilitate retrospective evaluation of ETAW, and hence CCUF, at field level. The current application is optimized for prevailing climate in four of the state’s main growing regions: San Joaquin Valley, Sacramento Valley, Central Coast, and North Coast. User inputs include crop type, soil texture, irrigation method, daily irrigation volume, daily rainfall, and seasonal start/stop dates to define the analysis period. Time series of fractional green canopy cover (Fc), based on Landsat and Sentinel-2 Earth-resource satellite observations, are imported from NASA’s Satellite Irrigation Management Support (SIMS) system. Grass reference evapotranspiration (ETo) time series are accessed from Spatial CIMIS (California Irrigation Management Information System). Daily crop height (h) is estimated as a simple function of typical maximum height for the given crop type (from FAO-56) and Fc. A vegetation density coefficient (Kd) is derived from Fc and h. Stomatal control factors during mid-and late-season are applied to tree and vine crops. Typical values for minimum daily relative humidity and mean daily windspeed, derived from historical CIMIS weather data, are used to correct for regional deviations from standard climate (defined as RHmin=45%, windspeed =2m/s). The resulting daily basal crop coefficient (Kcb) represents the ET of a well-watered crop with minimal soil evaporation, relative to ETo. A soil water balance sub-model for the top 0.1 m is used to calculate daily evaporation coefficients (Ke). A second sub-model applies to the root zone to calculate crop water stress coefficients (Ks) and effective precipitation (Pe), which is the fraction of rainfall that is available for crop use. Those coefficients are combined with Kcb and ETo to calculate daily ETc. ETAW is then derived as cumulative ETc less cumulative Pe. For verification purposes, sensor installations were used to measure seasonal ETc in commercial fields for several annual and perennial specialty crops by soil water balance and energy balance methods. Model estimates of seasonal ETc show mean absolute error of <10% compared to the ground measurements.

Derivation↗

NASA NTRS2013

Advanced Water Purification System for In Situ Resource Utilization

A main goal in the field of In Situ Resource Utilization is to develop technologies that produce oxygen from regolith to provide consumables to an extraterrestrial outpost. The processes developed reduce metal oxides in the regolith to produce water, which is then electrolyzed to produce oxygen. Hydrochloric and hydrofluoric acids are byproducts of the reduction processes, which must be removed to meet electrolysis purity standards. We previously characterized Nation, a highly water selective polymeric proton-exchange membrane, as a filtration material to recover pure water from the contaminated solution. While the membranes successfully removed both acid contaminants, the removal efficiency of and water flow rate through the membranes were not sufficient to produce large volumes of electrolysis-grade water. In the present study, we investigated electrodialysis as a potential acid removal technique. Our studies have shown a rapid and significant reduction in chloride and fluoride concentrations in the feed solution, while generating a relatively small volume of concentrated waste water. Electrodialysis has shown significant promise as the primary separation technique in ISRU water purification processes.

Anthony, Stephen M.↗

NASA NTRS2014

Advanced Water Purification System for In Situ Resource Utilization Project

A main goal in the field of In Situ Resource Utilization is to develop technologies that produce oxygen from regolith to provide consumables to an extratrrestrial outpost. The processes developed reduce metal oxides in the regolith to produce water, which is then electrolyzed to produce oxygen. Hydrochloric and hydrofluoric acids are byproducts of the reduction processes, which must be removed to meet electrolysis purity standards. We previously characterized Nation, a highly water selective polymeric proton-exchange membrane, as a filtrtion material to recover pure water from the contaminated solution. While the membranes successfully removed both acid contaminants, the removal efficiency of and water flow rate through the membranes were not sufficient to produce large volumes of electrolysis-grade water. In the present study, we investigated electrodialysis as a potential acid removable technique. Our studies have show a rapid and significant reduction in chloride and fluoride concentrations in the feed solution, while generating a relatively small volume of concentrated waste water. Electrodialysis has shown significant promise as the primary separation technique in ISRU water purification processes.

Technology Portfolio System↗

NASA NTRS2016

Modeling Global Water Use for the 21st Century: Water Futures and Solutions (WFaS) Initiative and Its Approaches

To sustain growing food demand and increasing standard of living, global water use increased by nearly 6 times during the last 100 years, and continues to grow. As water demands get closer and closer to the water availability in many regions, each drop of water becomes increasingly valuable and water must be managed more efficiently and intensively. However, soaring water use worsens water scarcity conditions already prevalent in semi-arid and arid regions, increasing uncertainty for sustainable food production and economic development. Planning for future development and investments requires that we prepare water projections for the future. However, estimations are complicated because the future of the world's waters will be influenced by a combination of environmental, social, economic, and political factors, and there is only limited knowledge and data available about freshwater resources and how they are being used. The Water Futures and Solutions (WFaS) initiative coordinates its work with other ongoing scenario efforts for the sake of establishing a consistent set of new global water scenarios based on the shared socio-economic pathways (SSPs) and the representative concentration pathways (RCPs). The WFaS "fast track" assessment uses three global water models, namely H08, PCR-GLOBWB, and WaterGAP. This study assesses the state of the art for estimating and projecting water use regionally and globally in a consistent manner. It provides an overview of different approaches, the uncertainty, strengths and weaknesses of the various estimation methods, types of management and policy decisions for which the current estimation methods are useful. We also discuss additional information most needed to be able to improve water use estimates and be able to assess a greater range of management options across the water-energy-climate nexus.

soaring↗

NASA NTRS1985

Photochemical modelling of Venus clouds using Pioneer Venus data

In order to understand the evolution of water on Venus, we must know the hydrogen escape flux as a function of the tropospheric water abundance. We have studied the connection between total stratospheric hydrogen and exobase hydrogen available to non-thermal escape processes and examined the details of the photochemical trap for water at the Venus cloud tops. Our immediate goal is to calculate the stratospheric water abundance as a function of the tropospheric water abundance. Photochemical production of H2SO4 acts as a sink for both water and sulfur and is capable of keeping stratospheric abundances low if a proper balance exists between the tropospheric abundances. If production of H2SO4 were the only sink for H2O and SO2, the excess in tropospheric abundance of one over the other would reach the stratosphere, and the functional dependence of stratospheric H2O on tropospheric H2O would be linear near the present state. On Venus, however, sulfuric acid condenses at cloud top temperatures and the resulting aerosols can absorb additional water of hydration. This complicates the water budget, increasing the efficiency of sulfur as a sink for water. We have investigated the balance between tropospheric H2O and SO2 and how delicate the balance is. Our major conclusions from this work are the following: (1) H2O and SO2 are mutually limiting if proper tropospheric balance is maintained; (2) changes in tropospheric abundances on the order of 5 ppm are significant; and (3) changes in mixing rates near the cloud tops can cause dramatic changes in SO2 without causing dramatic changes in H2O.

Mcelroy, Michael B.↗

NASA NTRSDate not supplied

Test Results for the SEA Ice Crystal Detector (ICD) under SLD Conditions at the NASA IRT

The Science Engineering Associates hot-wire Ice Crystal Detector was tested under Appendix C and Supercooled Large Drop Conditions at the NASA Icing Research Tunnel, with the purpose of comparing the measurements to the tunnel LWC calibration, and to test the performance of the mixed-phase retrievals of the probe. The liquid water content measured by the total water content sensor of the probe agreed well with the tunnel calibration over a wide range of MVDs, not unexpectedly since the tunnel was calibrated with a similar Multiwire hot-wire probe. A scale factor difference of about 7% was attributed to the lack of an efficiency correction for the Ice Crystal Detector at smaller median volume diameters, and typical sample area uncertainties of liquid water content devices. In addition, the simultaneous equations that are used to retrieve liquid and ice water contents were tested under liquid and glaciated conditions. Using constant ice and water efficiencies for each wire, the equations were found to produce a large and false ice water content retrieval in large median volume diameter liquid cases. By applying a liquid efficiency to the liquid water content sensor that varied with median volume diameter, retrievals were improved such that false ice water content was less than ±10% of the total water content out to the 460 μm median volume diameter limit of the testing. The probe was also tested in glaciated conditions by freezing out a small median volume diameter spray. Using constant ice efficiencies for the two sensors provided from aircraft measurements, the retrieved ice water content was about 40% higher than expected for the case presented, likely due to the ice efficiencies that were used from aircraft measurements of natural clouds being too low for the tunnel’s glaciated sprays. Application of ice efficiencies that vary with particle size and potentially other parameters will be explored for future improvement of retrievals.

Air Craft Icing↗

NASA NTRS2021

Test Results for the SEA Ice Crystal Detector (ICD) under SLD Conditions at the NASA IRT

o Aircraft Icing↗

NASA NTRS1988

Physical processes in polar stratospheric ice clouds

A one dimensional model of cloud microphysics was used to simulate the formation and evolution of polar stratospheric ice clouds. Some of the processes which are included in the model are outlined. It is found that the clouds must undergo preferential nucleation upon the existing aerosols just as do tropospheric cirrus clouds. Therefore, there is an energy barrier between stratospheric nitric acid particles and ice particles implying that nitric acid does not form a continuous set of solutions between the trihydrate and ice. The Kelvin barrier is not significant in controlling the rate of formation of ice particles. It was found that the cloud properties are sensitive to the rate at which the air parcels cool. In wave clouds, with cooling rates of hundreds of degrees per day, most of the existing aerosols nucleate and become ice particles. Such clouds have particles with sizes on the order of a few microns, optical depths on order of unity and are probably not efficient at removing materials from the stratosphere. In clouds which form with cooling rates of a few degrees per day or less, only a small fraction of the aerosols become cloud particles. In such clouds the particle radius is larger than 10 microns, the optical depths are low and water vapor is efficiently removed. Seasonal simulations show that the lowest water vapor mixing ratio is determined by the lowest temperature reached, and that the time when clouds disappear is controlled by the time when temperatures begin to rise above the minimum values.

Toon, Owen B.↗

NASA NTRS1980

Hydrogen production by photoelectrolytic decomposition of H2O using solar energy

Photoelectrochemical systems for the efficient decomposition of water are discussed. Semiconducting d band oxides which would yield the combination of stability, low electron affinity, and moderate band gap essential for an efficient photoanode are sought. The materials PdO and Fe-xRhxO3 appear most likely. Oxygen evolution yields may also be improved by mediation of high energy oxidizing agents, such as CO3(-). Examination of several p type semiconductors as photocathodes revealed remarkable stability for p-GaAs, and also indicated p-CdTe as a stable H2 photoelectrode. Several potentially economical schemes for photoelectrochemical decomposition of water were examined, including photoelectrochemical diodes and two stage, four photon processes.

Rauh, R. D.↗

NASA NTRS2010

Using Leaf Chlorophyll to Parameterize Light-Use-Efficiency Within a Thermal-Based Carbon, Water and Energy Exchange Model

Chlorophylls absorb photosynthetically active radiation and thus function as vital pigments for photosynthesis, which makes leaf chlorophyll content (C(sub ab) useful for monitoring vegetation productivity and an important indicator of the overall plant physiological condition. This study investigates the utility of integrating remotely sensed estimates of C(sub ab) into a thermal-based Two-Source Energy Balance (TSEB) model that estimates land-surface CO2 and energy fluxes using an analytical, light-use-efficiency (LUE) based model of canopy resistance. The LUE model component computes canopy-scale carbon assimilation and transpiration fluxes and incorporates LUE modifications from a nominal (species-dependent) value (LUE(sub n)) in response to short term variations in environmental conditions, However LUE(sub n) may need adjustment on a daily timescale to accommodate changes in plant phenology, physiological condition and nutrient status. Day to day variations in LUE(sub n) were assessed for a heterogeneous corn crop field in Maryland, U,S.A. through model calibration with eddy covariance CO2 flux tower observations. The optimized daily LUE(sub n) values were then compared to estimates of C(sub ab) integrated from gridded maps of chlorophyll content weighted over the tower flux source area. The time continuous maps of daily C(sub ab) over the study field were generated by focusing in-situ measurements with retrievals generated with an integrated radiative transfer modeling tool (accurate to within +/-10%) using at-sensor radiances in green, red and near-infrared wavelengths acquired with an aircraft imaging system. The resultant daily changes in C(sub ab) within the tower flux source area generally correlated well with corresponding changes in daily calibrated LUE(sub n) derived from the tower flux data, and hourly water, energy and carbon flux estimation accuracies from TSEB were significantly improved when using C(sub ab) for delineating spatio-temporal variations in LUE(sub n). The results demonstrate the synergy between thermal infrared and shortwave reflective wavebands in producing valuable remote sensing data for operational monitoring of carbon and water fluxes.

Houlborg, Rasmus↗

NASA NTRS1985

An experiment to detect gut monopoles

Recent advances in the development of Grand Unification Theories have led to several interesting predictions. One of these states that Grand Unification Monopoles (GUMs) exist as solutions in may nonabelian gauge theories. Another consequence of Unification is the possibility of baryon decay. The efficiency of the water tank detector in registering a Rubakov type decay will vary with both the interaction length and the GUM's velocity, expressed in terms of beta ( 0.01). The efficiency decreases at large values of because of the limited resolving time of the detector (approx. 50 ns). At lower values of Beta the time between interactions is such that the criterion of 4 events in 2 mu s can no longer be satisfied. The Rubakov experiment has now been in operation for almost 2 years with an estimated live time of 80%. During this time no candidate events have been observed leading to an estimated upper limit on the flux of 7.82 x 0.00001 m(-2) d(-1) Sr(-1). The ionization loss detection system has only recently come on line and as yet no results are available from this experiment.

Macneill, G.↗

NASA NTRS1977

Thermochemical water decomposition

At present, nearly all of the hydrogen consumed in the world is produced by reacting hydrocarbons with water. As the supply of hydrocarbons diminishes, the problem of producing hydrogen from water alone will become increasingly important. Furthermore, producing hydrogen from water is a means of energy conversion by which thermal energy from a primary source, such as solar or nuclear fusion of fission, can be changed into an easily transportable and ecologically acceptable fuel. The attraction of thermochemical processes is that they offer the potential for converting thermal energy to hydrogen more efficiently than by water electrolysis. A thermochemical hydrogen-production process is one which requires only water as material input and mainly thermal energy, or heat, as an energy input. Attention is given to a definition of process thermal efficiency, the thermodynamics of the overall process, the single-stage process, the two-stage process, multistage processes, the work of separation and a process evaluation.

Funk, J. E.↗