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Dust Storm Impacts on Human Mars Mission Equipment and Operations

Although it is tempting to use dust impacts on Apollo lunar exploration mission equipment and operations as an analog for human Mars exploration, there are a number of important differences to consider. Apollo missions were about a week long; a human Mars mission will start at least two years before crew depart from Earth, when cargo is pre-deployed, and crewed mission duration may be over 800 days. Each Apollo mission landed at a different site; although no decisions have been made, NASA is investigating multiple human missions to a single Mars landing site, building up capability over time and lowering costs by re-using surface infrastructure. Apollo missions used two, single-use spacecraft; a human Mars mission may require as many as six craft for different phases of the mission, most of which would be re-used by subsequent crews. Apollo crews never ventured more than a few kilometers from their lander; Mars crews may take "camping trips" a hundred kilo-meters or more from their landing site, utilizing pressurized rovers to explore far from their base. Apollo mission designers weren't constrained by human for-ward contamination of the Moon; if we plan to search for evidence of life on Mars we'll have to be more careful. These differences all impact how we will mitigate and manage dust on our human Mars mission equipment and operations.

Rucker, M. A.↗

The Effect of Acoustic Disturbances on the Operation of the Space Shuttle Main Engine Fuel Flowmeter

The Space Shuttle Main Engine (SSME) uses a turbine fuel flowmeter (FFM) in its Low Pressure Fuel Duct (LPFD) to measure liquid hydrogen flowrates during engine operation. The flowmeter is required to provide accurate and robust measurements of flow rates ranging from 10000 to 18000 GPM in an environment contaminated by duct vibration and duct internal acoustic disturbances. Errors exceeding 0.5% can have a significant impact on engine operation and mission completion. The accuracy of each sensor is monitored during hot-fire engine tests on the ground. Flow meters which do not meet requirements are not flown. Among other parameters, the device is screened for a specific behavior in which a small shift in the flow rate reading is registered during a period in which the actual fuel flow as measured by a facility meter does not change. Such behavior has been observed over the years for specific builds of the FFM and must be avoided or limited in magnitude in flight. Various analyses of the recorded data have been made prior to this report in an effort to understand the cause of the phenomenon; however, no conclusive cause for the shift in the instrument behavior has been found. The present report proposes an explanation of the phenomenon based on interactions between acoustic pressure disturbances in the duct and the wakes produced by the FFM flow straightener. Physical insight into the effects of acoustic plane wave disturbances was obtained using a simple analytical model. Based on that model, a series of three-dimensional unsteady viscous flow computational fluid dynamics (CFD) simulations were performed using the MSFC PHANTOM turbomachinery code. The code was customized to allow the FFM rotor speed to change at every time step according to the instantaneous fluid forces on the rotor, that, in turn, are affected by acoustic plane pressure waves propagating through the device. The results of the simulations show the variation in the rotation rate of the flowmeter due to the interaction of the flow straightener wakes and the upstream propagating acoustic waves. A detailed analysis of the acoustic disturbance effects is presented along with an assessment of the impact on measurement accuracy.

Marcu, Bogdan↗

Converter Compressor Building, SWMU 089 Monitoring Well 21 Area Implementation Work Plan Kennedy Space Center, Florida

This Implementation Work Plan (IWP) was prepared by Tetra Tech, Inc., for the National Aeronautics and Space Administration (NASA) under Indefinite Delivery Indefinite Quantity (IDIQ) Contract 80KSC019D0011/80KSC019F0070, for the implementation of a bioremediation Interim Measure (IM) at the Converter Compressor Building (CCB) site located at Kennedy Space Center (KSC), Florida. The location of CCB within KSC is shown on Figure A-1. CCB has been designated as Solid Waste Management Unit (SWMU) 089 under KSC’s Resource Conservation and Recovery Act (RCRA) Corrective Action Program. The overall Corrective Action Objective (CAO) for CCB is to reduce concentrations of trichloroethene (TCE), cis-1,2-dichloroethene (cDCE), trans-1,2-dichloroethene (tDCE), and vinyl chloride (VC) to less than State of Florida Groundwater Cleanup Target Levels (GCTLs). The objective for the IM associated with this IM is to reduce groundwater concentrations for the contaminants of concern (COCs) to less than their Natural Default Attenuation Concentrations (NADCs) within the Monitoring Well 21 Area (herein referred to as MW21 Area) via bioremediation injections to support transition to long term monitoring (LTM). This IWP describes the activities that will be performed for the treatment of the MW21 Area. The Revision 1 CCB MW21 Area Interim Measure Work Plan (IMWP; NASA, 2024), which was approved by the Florida Department of Environmental Protection (FDEP) on December 26, 2024, was used as the design basis for this IWP.

Mark Jonnet↗

Panel Session 108: Technology Transfer and Commercialization: Innovative Solutions for Global Opportunities

This panel focus was to build the connection between innovative solutions and the various industries looking for more efficient methods, products, and processes in Tech Transfer and Commercialization. This panel had interest across the entire conference base, whether they are encountering a challenge, introducing an innovative solution, or are the host that is trying to get from a pure research / Research, Development, Demonstration, Testing, and Evaluation solution to one that is commercially viable and robust enough for long term and/or high risk deployment scenarios and which will support greater chance of success and positive outcomes. Panelists with presentations: Practical, Successful Technology Transfer (Laurie Judd); Technology Needs for Clean-up of Mercury Contamination on the Oak Ridge Reservation (Renee Echols); US DOE Office of Technology Transitions (Kyle Wiley); Technology Transfer in Support of Delivering Clean-up Missions (Kristan Schruder); Mission to Market (J. Chris Ford)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

The Virginia Earth System Science Scholars (VESSS) Experience: Inspiring High School Students in Stem Through Mentorship and Collaborative Skills Development

Since 2016, the Virginia Earth System Science Scholars (VESSS) program offered by the Virginia Space Grant Consortium (VSGC) has provided an interactive science, technology, engineering, and mathematics learning experience for Virginia high school juniors and seniors. The VESSS program was created through a partnership with VSGC, NASA Langley Research Center (LaRC), and Hampton University to engage students in learning about Earth’s climate change and its global impacts. High school students from all areas of Virginia learn about Earth science and climate change in a 16 week online course focused on the Earth’s surface and interior, atmospheric composition, weather, water energy cycles, and climate variability. Students that complete the online course are invited to a no-cost seven-day residential summer academy at NASA LaRC where students are divided into teams based on four of the major spheres of study for Earth: atmosphere, biosphere, hydrosphere, and lithosphere. Each team is guided by a Master Teacher and teams of undergraduate student interns who were also previous VESSS scholars. Students interview for team positions and are given a role reflecting an actual satellite design team position such as project scientist, research scientist, budget analyst, launch and orbit analyst, contamination analyst, and education and public outreach specialist. The students spend a week mentored by NASA and industry scientists and engineers as they learn how to select science goals and objectives, select science instruments, balance a mission budget, determine the mission launch location and orbit, and communicate the importance of the mission to the public. Each team produces a mission proposal, and at the end of the week, each team presents their portion of the mission to a panel of experts, followed by a question and answer period. Through this week students learn teamwork, communication, time management, meeting management, and research skills. Project work is supplemented by team-building activities, NASA facility tours, and lectures by acclaimed guest speakers such as Dr. Christine Darden, a NASA “Hidden Figure.” Students have conveyed through course evaluations and testimonials not only the vast personal learning and growth they achieved, but also the new perspectives they gained on future STEM career fields and opportunities to explore.

Elaine Seasly↗

Cosmology with second- and third-order shear statistics for the Dark Energy Survey: Methods and simulated analysis

We present a new pipeline designed for the robust inference of cosmological parameters using both second- and third-order shear statistics. We build a theoretical model for rapid evaluation of three-point correlations using our fastnc code and integrate it into the cosmosis framework. We measure the two-point functions 𝜉 ± and the full configuration-dependent three-point shear correlation functions across all auto- and cross-redshift bins. We compress the three-point functions into the mass aperture statistic ⟨ℳ$^{3}_{ap}$⟩ for a set of 796 simulated shear maps designed to model the Dark Energy Survey Year 3 data. We estimate from it the full covariance matrix and model the effects of intrinsic alignments, shear calibration biases and photometric redshift uncertainties. We apply scale cuts to minimize the contamination from the baryonic signal as modeled through hydrodynamical simulations. We find a significant improvement of 83% on the figure of merit in the Ω m − 𝑆 8 plane when we add the ⟨ℳ$^{3}_{ap}$⟩ data to 𝜉 ± . Here, we present our findings for all relevant cosmological and systematic uncertainty parameters and discuss the complementarity of third-order and second-order statistics.

79 ASTRONOMY AND ASTROPHYSICS↗

26th Space Simulation Conference Proceedings. Environmental Testing: The Path Forward

Topics covered include: A Multifunctional Space Environment Simulation Facility for Accelerated Spacecraft Materials Testing; Exposure of Spacecraft Surface Coatings in a Simulated GEO Radiation Environment; Gravity-Offloading System for Large-Displacement Ground Testing of Spacecraft Mechanisms; Microscopic Shutters Controlled by cRIO in Sounding Rocket; Application of a Physics-Based Stabilization Criterion to Flight System Thermal Testing; Upgrade of a Thermal Vacuum Chamber for 20 Kelvin Operations; A New Approach to Improve the Uniformity of Solar Simulator; A Perfect Space Simulation Storm; A Planetary Environmental Simulator/Test Facility; Collimation Mirror Segment Refurbishment inside ESA s Large Space; Space Simulation of the CBERS 3 and 4 Satellite Thermal Model in the New Brazilian 6x8m Thermal Vacuum Chamber; The Certification of Environmental Chambers for Testing Flight Hardware; Space Systems Environmental Test Facility Database (SSETFD), Website Development Status; Wallops Flight Facility: Current and Future Test Capabilities for Suborbital and Orbital Projects; Force Limited Vibration Testing of JWST NIRSpec Instrument Using Strain Gages; Investigation of Acoustic Field Uniformity in Direct Field Acoustic Testing; Recent Developments in Direct Field Acoustic Testing; Assembly, Integration and Test Centre in Malaysia: Integration between Building Construction Works and Equipment Installation; Complex Ground Support Equipment for Satellite Thermal Vacuum Test; Effect of Charging Electron Exposure on 1064nm Transmission through Bare Sapphire Optics and SiO2 over HfO2 AR-Coated Sapphire Optics; Environmental Testing Activities and Capabilities for Turkish Space Industry; Integrated Circuit Reliability Simulation in Space Environments; Micrometeoroid Impacts and Optical Scatter in Space Environment; Overcoming Unintended Consequences of Ambient Pressure Thermal Cycling Environmental Tests; Performance and Functionality Improvements to Next Generation Thermal Vacuum Control System; Robotic Lunar Lander Development Project: Three-Dimensional Dynamic Stability Testing and Analysis; Thermal Physical Properties of Thermal Coatings for Spacecraft in Wide Range of Environmental Conditions: Experimental and Theoretical Study; Molecular Contamination Generated in Thermal Vacuum Chambers; Preventing Cross Contamination of Hardware in Thermal Vacuum Chambers; Towards Validation of Particulate Transport Code; Updated Trends in Materials' Outgassing Technology; Electrical Power and Data Acquisition Setup for the CBER 3 and 4 Satellite TBT; Method of Obtaining High Resolution Intrinsic Wire Boom Damping Parameters for Multi-Body Dynamics Simulations; and Thermal Vacuum Testing with Scalable Software Developed In-House.

Packard, Edward A.↗

OSS-1/contamination monitor

A 20-cm high, 18-cm wide, and 30-cm long (8x7x12 inch) box weighing about 7 kg (15 lbs) and consuming about 7 watts of power was carried on the OSS-1 pallet to monitor the mass build-up or accretion of condensible, volatile materials on surfaces in the shuttle bay during all phases of ascent, on-orbit, and descent. Passively thermally controlled, the box holds two witness samples and four actively temperature controlled quartz crystal microbalances (TQCM) whose temperature can vary from -60 C to +80 C. Graphs show the accretion indicated by the TQCM during the launch and early orbital phase. Conditions during tail to the Sun, nose to the Sun, and bay to the Sun attitudes of the shuttle during STS-3 are reflected in temperatures indicated by the OSS-1 thermistor. These temperatures influence outgassing rates of various materials as well as measurements made by the contamination monitor package. The parameters that bear on TQCM measurements data are shown in graphs and discussed.

Kruger, R.↗

Metabolic engineering to improve production of 3-hydroxypropionic acid from corn-stover hydrolysate in Aspergillus species

Fuels and chemicals derived from non-fossil sources are needed to lessen human impacts on the environment while providing a healthy and growing economy. 3-hydroxypropionic acid (3-HP) is an important chemical building block that can be used for many products. Biosynthesis of 3-HP is possible; however, low production is typically observed in those natural systems. Biosynthetic pathways have been designed to produce 3-HP from a variety of feedstocks in different microorganisms. In this study, the 3-HP β-alanine pathway consisting of aspartate decarboxylase, β-alanine-pyruvate aminotransferase, and 3-hydroxypropionate dehydrogenase from selected microorganisms were codon optimized for Aspergillus species and placed under the control of constitutive promoters. The pathway was introduced into Aspergillus pseudoterreus and subsequently into Aspergillus niger, and 3-HP production was assessed in both hosts. A. niger produced higher initial 3-HP yields and fewer co-product contaminants and was selected as a suitable host for further engineering. Proteomic and metabolomic analysis of both Aspergillus species during 3-HP production identified genetic targets for improvement of flux toward 3-HP including pyruvate carboxylase, aspartate aminotransferase, malonate semialdehyde dehydrogenase, succinate semialdehyde dehydrogenase, oxaloacetate hydrolase, and a 3-HP transporter. Overexpression of pyruvate carboxylase improved yield in shake-flasks from 0.09 to 0.12 C-mol 3-HP C-mol -1 glucose in the base strain expressing 12 copies of the β-alanine pathway. Deletion or overexpression of individual target genes in the pyruvate carboxylase overexpression strain improved yield to 0.22 C-mol 3-HP C-mol -1 glucose after deletion of the major malonate semialdehyde dehydrogenase. Further incorporation of additional β-alanine pathway genes and optimization of culture conditions (sugars, temperature, nitrogen, phosphate, trace elements) for 3-HP production from deacetylated and mechanically refined corn stover hydrolysate improved yield to 0.48 C-mol 3-HP C-mol -1 sugars and resulted in a final titer of 36.0 g/L 3-HP. The results of this study establish A. niger as a host for 3-HP production from a lignocellulosic feedstock in acidic conditions and demonstrates that 3-HP titer and yield can be improved by a broad metabolic engineering strategy involving identification and modification of genes participated in the synthesis of 3-HP and its precursors, degradation of intermediates, and transport of 3-HP across the plasma membrane.

09 BIOMASS FUELS↗

Carbon Capture Pilot at Vicksburg Containerboard Mill (Final Technical Report)

This is the final technical report for the DOE-OCED project DE-CD0000051. The report provides the progress at the close of the project. The objective of the project is to design and build a large pilot plant for carbon dioxide (CO 2 ) capture from a pulp and paper (P&P) mill using RTI’s non-aqueous solvent (NAS) technology at a capacity of 120,000 t-CO 2 /year, with >90% CO 2 captured. The pilot plant will be used for testing and evaluating the NAS capture process using real flue gas from the P&P mill’s power boiler for a minimum of 1 year of parametric testing and a minimum of 2,000 hours of continuous long-term testing. The testing will provide data for process optimization and scale-up for the P&P industry, provide information on interaction of flue gas contaminants on solvent performance and degradation, and inform strategies for emission control. At the end of the project, the pilot plant will be managed by International Paper (IP), the host site owner, which will continue to capture CO 2 , sequester the captured CO 2 , and be eligible for the 45Q credit.

42 ENGINEERING↗

Random Vibration Simulation and Testing of a Compact, Magnetic Bearing Supported Blower for Space Applications

NASA is developing a next-generation CO2 removal system, the Four Bed Carbon Dioxide Scrubber (4BCO2), which will use the International Space Station (ISS) as a testbed. A key component of both the existing and the new system is the blower that provides the airflow through the CO2 sorbent beds. To improve performance and reliability, magnetic bearings will be used in lieu of more conventional bearings (e.g. ball bearings or hydrodynamicbearings) to improve resistance to contaminants and enable extensibility with regards to blower speed, pressure rise and mass flow rate. The new blower features a high-efficiency permanent magnet motor, a five-axis, active magnetic bearing system, and a compact controller containing both a variable speed drive and magnetic bearing controller. The blower uses a centrifugal impeller to pull air from the inlet port and drive it through an annular space around the motor and magnetic bearing components to the exhaust port. Technical challenges of the blower and controller development include survival of the blower system under launch random vibration loads, operation in microgravity, packaging under strict size and weight requirements, and successful operation during 4BCO2 operational changeovers. Each serial build of the blower must pass a severe random vibration test to prove it will survive launch conditions. This paper discusses the vibration test requirements and provides details of a simulation performed to estimate the peak backup bearing displacements and loads. Results from the successful random vibration testing of the prototype build are discussed and compared to the simulation.

bearings↗

Air Exchange Rate Impact on Activity Equilibrium Factors and Inhalation Fractional Equilibrium Factors for Rn, Xe, Kr, Ar, Ne, and Their Progeny in Vapor Intrusion, Risk, and Dose Models

Exposure to the radioactive noble gasses, especially radon, is of high concern and poses a significant risk to humans in an indoor air environment as the second leading cause of lung cancer in the United States. To evaluate and minimize the risks posed by these gasses, it is important to understand their radiological and physical properties. The EPA’s Radon Vapor Intrusion Screening Level (RVISL) calculator calculates indoor air RVISLs based on target working levels (WLs), target excess lifetime cancer risk (ELCR), and annual dose limits for the actinon (Rn-219), thoron (Rn-220), and radon (Rn-222) decay series. The RVISLs are based on inhalation and submersion in gas cloud exposure routes for residential and commercial settings. The RVISLs are analogous to preliminary remediation goals (PRGs) and dose compliance concentrations (DCCs), where the isotope-specific values are in units of activity concentration (activity per unit volume). If the concentration of a parent isotope of radon or its progeny is found to exceed the RVISL, then further action to ensure cleanup of the contaminant may be necessary. In residential and commercial settings, the RVISLs will vary based on the air exchange rate present. The EPA’s Radionuclide PRG and DCC Calculators also assess the risk/dose from noble gases in the air due to household use of water like showering. In this study, a computational method in MATLAB was developed to determine the impact of the air exchange rate on the activity equilibrium factor (A eq ) and the inhalation fractional equilibrium factor (F eq ). Both factors are values that reflect the equilibrium concentrations of progeny to their parent in the air. These factors have a direct impact on the RVISL, PRG, and DCC calculations of WL, ELCR, and annual dose, respectively. This study builds on a previous report that only focused on actinon, thoron, and radon by revisiting the original A eq and F eq calculation methods, as well as including the values for the Rn-207, Rn-209, Rn-210, Rn-211, Rn-215, Rn-216, Rn-217, Rn-218, Rn-223, Ne-24, Ar-42, Ar-43, Ar-44, Kr-74, Kr-75, Kr-76, Kr-77, Kr-88, Kr-89, Xe-120, Xe-121, Xe-122, Xe-123, Xe-135m, and Xe-138 decay chains, which are not currently available in literature. The EPA’s RVISL calculator will be updated to include the new A eq and F eq values for the actinon, thoron, and radon decay chains, while the rest of the calculators will incorporate all the new A eq and F eq values as appropriate.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗

A Rapid Sequential Separation Method for Determination of Actinides and TENORM in Fracking Wastes - 20223

With recent advances in unconventional drilling technology in the US and around the world, the risks of environmental contamination and exposure due to technologically enhanced naturally occurring radioactive materials (TENORM) from fracking wastes have also surfaced. Although the Permian Basin (southeastern New Mexico, western Texas) has long been a modest producer of oil, the advent of fracking technology a decade ago turned it into hot property for producers. A 2018 assessment of undiscovered, technically recoverable continuous oil and gas resources by the U.S. Geological Survey estimates an average 46.3 billion barrels of oil and 281 trillion cubic feet of gas. This is likely to increase the use of unconventional drilling and TENORM generation. TENORM concentrations in oil and gas exploration and production waste can be several hundred to several thousand times higher than background TENORM concentrations. Both the thorium and uranium decay chains contribute to airborne radionuclides arising from the radon gas escaping the ground and subsequently decaying as airborne particulates. Additionally, radon decay products {sup 210}Pb and {sup 210}Po can build up in scale on the internal surfaces of oil and gas handling pipes and in sludge in refineries, becoming potential inhalation and ingestion hazards for workers. Furthermore, southeastern NM is also home to world's only licensed and operating transuranic nuclear waste repository, the DoE's Waste Isolation Pilot Plant (WIPP). Plutonium isotopes ({sup 239+240}Pu) and {sup 241}Am, are expected to account for more than 99% of the total radioactivity scheduled for disposal in the WIPP repository. Thus, an improved understanding of the environmental fate and transport of TENORM, liberated by unconventional drilling, is essential to assess how best to protect individuals and the environment. In this context, accurate measurement of TENORM and actinides in environmental and biological samples is essential. In this presentation, a new sequential method for the separation and pre-concentration of actinides (Pu, Am, Np) and TENORM (Po, U and Th) derived from oil and gas exploration is proposed. The TEVA method involves a rapid co-precipitation step to remove matrix interferences from the samples, followed by plutonium oxidation state adjustment to Pu (IV) and an incubation period of ∼ 1 hour at 50-60 deg. C to allow the resultant Po (II) to oxidize into Po(IV). The polonium, neptunium, thorium and plutonium are then separated on a TEVA column, while americium and uranium are separated on a TRU column. After separation, the alpha counting source was prepared by micro-precipitation with copper sulfide (CuS) for polonium and neodymium fluoride (NdF{sub 3}) for actinides. The efficiency and reliability of the procedures were tested by analyzing filter, drinking water and frack sand samples. The method is simple, robust and can be performed quickly with excellent removal of interferences, high chemical recovery and very good alpha peak resolution. (authors)

07 ISOTOPE AND RADIATION SOURCES↗

Photolysis products of CO, NH3 aND H2O and their significance to reactions on interstellar grains

With the increase in evidence that interstellar grains are the basic building blocks of comets and with the realization that comet collisions with the earth have probably occured at a much higher frequency than earlier assumed it may be presumed that interstellar dust chemistry played an important role in the early chemistry of the earth. As a part of the study of the photochemical processes taking place on interstellar grains the photolysis of mixtures of CO, NH3 and H2O was performed at 10 K, 77K and 298K. The reaction products were determined by GC/MS and HPLC analysis to be lactic acid, glycolic acid, hydroxyacetamide, urea, biuret, oxamic acid, oxamide, glyceric acid and glyceramide. Ethylene glycol and glycerol were also detected but is is not clear at present whether these are true photoproducts or contaminants. The mechanism of formation of these molecules are discussed as well as their possible significance to the origins of life.

Ferris, J. P.↗

Trace Adsorptive Removal of PFAS from Water by Optimizing the UiO‐66 MOF Interface

Abstract The confluence of pervasiveness, bioaccumulation, and toxicity in freshwater contaminants presents an environmental threat second to none. Exemplifying this trifecta, per‐ and polyfluoroalkyl substances (PFAS) present an alarming hazard among the emerging contaminants. State‐of‐the‐art PFAS adsorbents used in drinking water treatment, namely, activated carbons and ion‐exchange resins, are handicapped by low adsorption capacity, competitive adsorption, and/or slow kinetics. To overcome these shortcomings, metal–organic frameworks (MOFs) with tailored pore size, surface, and pore chemistry are promising alternatives. Thanks to the compositional modularity of MOFs and polymer–MOF composites, herein we report on a series of water‐stable zirconium carboxylate MOFs and their low‐cost polymer‐grafted composites as C 8 –PFAS adsorbents with benchmark kinetics and “parts per billion” removal efficiencies. Bespoke insights into the structure–function relationships of PFAS adsorbents are obtained by leveraging interfacial design principles on solid sorbents, creating a synergy between the extrinsic particle surfaces and intrinsic molecular building blocks.

Ilić, Nebojša↗

Evaluating the performance of portable air filter walls for the James Webb Space Telescope launch campaign

The James Webb Space Telescope (JWST) launched from the Centre Spatial Guyanais (CSG) in December 2021. JWST’s requirements permitted processing in International Organization for Standardization (ISO) Class 7 or better facilities, but CSG was only equipped with ISO Class 8 facilities. To temporarily upgrade the air cleanliness in the Payload Processing Facility, Fueling Hall, and Final Assembly Building Encapsulation Hall, NASA provided two portable High Efficiency Particulate Air (HEPA) and carbon filter walls that were used in each location. The walls were comprised of stacks of two modules high and arranged in push-push configurations as shown to be most effective via Computational Fluid Dynamics simulations of expected floor layouts in each facility. After delivery to NASA’s Goddard Space Flight Center in 2020, the walls underwent initial verification measurements inside a cleanroom and validation testing in an uncontrolled area to quantify their improvement of air cleanliness and particle and molecular fallout. Validation testing showed improvements of 83-99% for airborne particle counts, 79-91% for particle fallout, and 50-90% for molecular fallout. The particle improvements were applied to the contamination budget analysis that tracked current and predicted future cleanliness against End-of-Life requirements for JWST’s critical surfaces. At CSG, the walls successfully maintained an ISO Class 7 environment or better within their envelope in each location, despite their presence in ISO Class 8 facilities with dense integration operations.

HEPA, Contamination Control, Filtration↗

Evaluating the Performance of Portable Air Filter Walls for the James Webb Space Telescope Launch Campaign

The James Webb Space Telescope (JWST) launched from the Centre Spatial Guyanais (CSG) in December 2021. JWST’s requirements permitted processing in International Organization for Standardization (ISO) Class 7 or better facilities, but CSG was only equipped with ISO Class 8 facilities. To temporarily upgrade the air cleanliness in the Payload Processing Facility, Fueling Hall, and Final Assembly Building Encapsulation Hall, NASA provided two portable High Efficiency Particulate Air (HEPA) and carbon filter walls that were used in each location. The walls were comprised of stacks of two modules high and arranged in push-push configurations as shown to be most effective via Computational Fluid Dynamics simulations of expected floor layouts in each facility. After delivery to NASA’s Goddard Space Flight Center in 2020, the walls underwent initial verification measurements inside a cleanroom and validation testing in an uncontrolled area to quantify their improvement of air cleanliness and particle and molecular fallout. Validation testing showed improvements of 83-99% for airborne particle counts, 79-91% for particle fallout, and 50-90% for molecular fallout. The particle improvements were applied to the contamination budget analysis that tracked current and predicted future cleanliness against End-of-Life requirements for JWST’s critical surfaces. At CSG, the walls successfully maintained an ISO Class 7 environment or better within their envelope in each location, despite their presence in ISO Class 8 facilities with dense integration operations.

HEPA, Contamination Control, Filtration↗

Using Models to Predict the Hygrothermal Performance of Equipment and Piping Insulation

The development of hygrothermal models began in earnest in the 1990s, with the initial emphasis on the performance of building envelope systems. Numerous large-scale building envelope failures associated with water intrusion drove this development. The physical principles of moisture transfer that apply to building envelopes are equally valid for equipment and piping insulation systems. The main advantage of modeling is that carefully characterized models can predict the long-term hygrothermal performance of any system under different climatic and interior conditions. Thermal insulations are commonly used on outdoor equipment and piping for different applications, such as thermal energy conservation and freeze protection. The insulated equipment usually experiences moisture intrusion due to many factors, such as the duration and frequency of moisture exposure, equipment operating temperature, insulation type, exposure temperature, weather conditions, equipment thermal cycling, and weatherproofing condition. Hygrothermal models have been employed to estimate the moisture pickup of insulated equipment and piping systems, as well as the moisture redistribution and subsequent change in thermal performance as these systems become contaminated with moisture. The hygrothermal model provides insights on the parameters influencing the time of wetness, the lateral redistribution of moisture along the pipe away from the leak, and the ease by which water escapes the insulation/jacketing systems. It has been shown that the moisture leak effect decreases rapidly with distance from the leak and that one- and two-dimensional hygrothermal simulations help to identify solutions to reduce conditions that support corrosion under insulation (CUI).

Shrestha, Som↗