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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 181 records · Page 10
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NASA NTRS2017

Method for the Collection, Gravimetric and Chemical Analysis of Nonvolatile Residue (NVR) on Surfaces

Nonvolatile residue (NVR), sometimes referred to as molecular contamination is the term used for the total composition of the inorganic and high boiling point organic components in particulates and molecular films deposited on critical surfaces surrounding space structures, with the particulate and NVR contamination originating primarily from pre-launch operations. The "nonvolatile" suggestion from the terminology NVR implies that the collected residue will not experience much loss under ambient conditions. NVR has been shown to have a dramatic impact on the ability to perform optical measurements from platforms based in space. Such contaminants can be detected early by the controlled application of various detection techniques and contamination analyses. Contamination analyses are the techniques used to determine if materials, components, and subsystems can be expected to meet the performance requirements of a system. Of particular concern is the quantity of NVR contaminants that might be deposited on critical payload surfaces from these sources. Subsequent chemical analysis of the contaminant samples by infrared spectroscopy and gas chromatography mass spectrometry identifies the components, gives semi-quantitative estimates of contaminant thickness, indicates possible sources of the NVR, and provides guidance for effective cleanup procedures. In this report, a method for the collection and determination of the mass of NVR was generated by the authors at NASA Langley Research Center. This report describes the method developed and implemented for collecting NVR contaminants, and procedures for gravimetric and chemical analysis of the residue obtained. The result of this NVR analysis collaboration will help pave the way for Langley's ability to certify flight hardware outgassing requirements in support of flight projects such as Stratospheric Aerosol and Gas Experiment III (SAGE III), Clouds and the Earth's Radiant Energy System (CERES), Materials International Space Station Experiment - X (MISSE-X), and Doppler Aerosol Wind Lidar (DAWN).

Gordon, Keith↗
NASA NTRS2018

The Opera Instrument: An Advanced Curation Development for Mars Sample Return Organic Contamination Monitoring

Mars Sample Return (MSR) requires strict organic contamination control (CC) and contamination knowledge (CK) as outlined by the Mars 2020 Organic Contamination Panel (OCP). This includes a need to monitor surficial organic contamination to a ng/sq. cm sensitivity level. Archiving and maintaining this degree of surface cleanliness may be difficult but has been achieved. MSR's CK effort will be very important because all returned samples will be studied thoroughly and in minute detail. Consequently, accurate CK must be collected and characterized to best interpret scientific results from the returned samples. The CK data are not only required to make accurate measurements and interpretations for carbon-depleted martian samples, but also to strengthen the validity of science investigations performed on the samples. The Opera instrument prototype is intended to fulfill a CC/CK role in the assembly, cleaning, and overall contamination history of hardware used in the MSR effort, from initial hardware assembly through post-flight sample curation. Opera is intended to monitor particulate and organic contamination using quartz crystal microbalances (QCMs), in a self-contained portable package that is cleanroom-compliant. The Opera prototype is in initial development capable of approximately 100 ng/sq. cm organic contamination sensitivity, with additional development planned to achieve 1 ng/sq. cm. The Opera prototype was funded by the 2017 NASA Johnson Space Center Innovation Charge Account (ICA), which provides funding for small, short-term projects.

Fries, M. D.↗
NASA NTRS1989

Contamination control program for the Extreme Ultraviolet Explorer instruments

A contamination-control program has been instituted for the optical components of the EUV Explorer satellite, whose 80-900 A range performance is easily degraded by particulate and molecular contamination. Cleanliness requirements have been formulated for the design, fabrication, and test phases of these instruments; in addition, contamination-control steps have been taken which prominently include the isolation of sensitive components in a sealed optics cavity. Prelaunch monitoring systems encompass the use of quartz crystal microbalances, particle witness plates, direct flight hardware sampling, and optical witness sampling of EUV scattering and reflectivity.

Ray, David C.↗
NASA NTRS1992

Implementation of the TOMS contamination control requirements in the former USSR

The American Total Ozone Mapping Spectrometer (TOMS) was integrated with the Russian Meteor-3 spacecraft and launched on August 15, 1991. Although the TOMS instrument was sensitive to both particulate and molecular contamination, the program for Meteor-3 had not formerly addressed contamination control in ground operations. In order to accommodate the TOMS cleanliness requirements, a contamination control program was successfully established from inception at both the Meteor-3 spacecraft plant near Moscow and at the launch site in Plesetsk.

Abrams, Eve M.↗
NASA NTRS1990

Contamination control program results from three years of ground operations on the Extreme Ultraviolet Explorer instruments

A stringent contamination-control plan has been developed for the optical components of the Extreme Ultraviolet Explorer instruments, whose performance in the 80-900 A wavelength range is highly sensitive to particulate and molecular contamination. The contamination-control program has been implemented over the last three years during assembly, test and calibration phases of the instrument. These phases have now been completed and the optics cavities of the instruments have been sealed until deployment in space. Various approaches are discussed which have been used during ground operations to meet optics' contamination goals within the project schedule and budget. The measured optical properties of EUV witness mirrors are also presented which remained with the flight mirrors during ground operations. These were used to track optical degradation due to contamination from the cleanroom and high-vacuum test-chamber environments.

Ray, David C.↗
NASA NTRS1972

Preparation, verification, and operational control of a large space-environment-simulation chamber for contamination sensitive tests

A 2-year program to prepare chamber A at the NASA Manned Spacecraft Center for Apollo telescope mount thermal-vacuum tests is discussed. This program covers modification to existing chamber systems, the development of facility and chamber operating procedures, the selection of chamber cleaning and control methods, and the development and evaluation of diagnostic instrumentation. Extensive efforts to ensure a minimum contamination environment for the Apollo telescope mount test series are illustrated. Recent thermal-vacuum tests of this chamber at progressive stages of cleanliness have demonstrated the success achieved in reducing the particulate and molecular contamination levels of the basic chamber interior.

Visentine, J. T.↗
NASA NTRS1993

Contamination design of a Scientific Instrument Protective Enclosure for the Hubble Space Telescope Servicing Mission

A Scientific Instrument Protective Enclosure (SIPE) was designed to accommodate second generation science instruments (SIs) for the Hubble Space Telescope (HST) First Servicing Mission (FSM). One of the main design drivers for the SIPE is to provide a protective environment for the SIs against particulate and molecular contaminants that pose a viable threat to the SI performance. The focus of this paper will detail the methodology incorporated in the design of the SIPE to provide a controlled environment for SI protection at the launch site, during pre-launch/launch activities, and during on-orbit operations in the Shuttle bay.

Hedgeland, Randy J.↗
NASA NTRS1988

A Study of Space Station Contamination Effects

A workshop was held with the specific objective of reviewing the state-of-knowledge regarding Space Station contamination, the extent to which the various categories of contamination can be predicted, and the extent to which the predicted levels would interfere with onboard scientific investigations or space station functions. The papers presented at the workshop are compiled and address the following topics: natural environment, plasma electromagnetic environment, optical environment, particulate environment, spacecraft contamination, surface physics processes, laboratory experiments and vented chemicals/contaminants.

Torr, M. R.↗
NASA NTRS1972

Analysis of microsize particulates

Unique methods for analyzing individual particles ranging in size from 0.01 to 1000 micrometers have been developed for investigation of nature of cosmic dust. Methods are applicable to particulate aerosols and contaminants characteristically encountered in studies of air pollution and in experiments designed to abate pollution.

Blanchard, M. B.↗
NASA NTRS1975

Results of examination of the nasal mucosa

The olfactory epithelium, but not the nasal respiratory epithelium, of the four pocket mice (Perognathus longimembris) that survived their flight on Apollo XVII showed both diffuse alterations and numerous disseminated focal lesions. The olfactory mucosa of the mouse that died during flight was also affected, but to a minor degree insofar as could be determined. All this was in contrast to the normal appearance of the olfactory mucosa of the numerous control animals. A number of possible causes were considered: systemic or regional infection; inhaled particulate material (seed dust); by-products from the KO2 bed in aerosol or particulate form; gas contaminants originating in the flight package; volatile substances from the dead mouse; weightlessness; and cosmic ray particle radiation. Where feasible, studies were conducted in an effort to rule in or rule out some of these potentially causative factors. No definitive conclusions were reached as to the cause of the lesions in the flight mice.

Kraft, L. M.↗
NASA NTRS1988

Environmental monitoring for Space Station WP01

External contamination monitoring instrumentation for the Space Station work package one (WP01) elements, were imposed on the contractor as deliverable hardware. The monitoring instrumentation proposed by the WP01 contractor in response to the contract requirement includes both real time measurements and passive samples. Real time measurement instrumentation consists of quartz crystal microbalances for molecular deposition, ion gaseous species identification. Internal environmental contamination monitoring for particulates is included in both Lab and HAB modules. Passive samples consists of four sample mounting plates mounted external to the Space Station modules, two on the U.S. LAB, and two on the HAB module.

Zwiener, J. M.↗
NASA NTRS1990

Space Station Environmental Health System water quality monitoring

One of the unique aspects of the Space Station is that it will be a totally encapsulated environment and the air and water supplies will be reclaimed for reuse. The Environmental Health System, a subsystem of CHeCS (Crew Health Care System), must monitor the air and water on board the Space Station Freedom to verify that the quality is adequate for crew safety. Specifically, the Water Quality Subsystem will analyze the potable and hygiene water supplies regularly for organic, inorganic, particulate, and microbial contamination. The equipment selected to perform these analyses will be commercially available instruments which will be converted for use on board the Space Station Freedom. Therefore, the commercial hardware will be analyzed to identify the gravity dependent functions and modified to eliminate them. The selection, analysis, and conversion of the off-the-shelf equipment for monitoring the Space Station reclaimed water creates a challenging project for the Water Quality engineers and scientists.

Vincze, Johanna E.↗
NASA NTRS1993

Space environment durability of beta cloth in LDEF thermal blankets

Beta cloth performance for use on long-term space vehicles such as Space Station Freedom (S.S. Freedom) requires resistance to the degrading effects of the space environment. The major issues are retention of thermal insulating properties through maintaining optical properties, preserving mechanical integrity, and generating minimal particulates for contamination-sensitive spacecraft surfaces and payloads. The longest in-flight test of beta cloth's durability was on the Long Duration Exposure Facility (LDEF), where it was exposed to the space environment for 68 months. The LDEF contained 57 experiments which further defined the space environment and its effects on spacecraft materials. It was deployed into low-Earth orbit (LEO) in Apr. 1984 and retrieved Jan. 1990 by the space shuttle. Among the 10,000 plus material constituents and samples onboard were thermal control blankets of multilayer insulation with a beta cloth outer cover and Velcro attachments. These blankets were exposed to hard vacuum, thermal cycling, charged particles, meteoroid/debris impacts, ultraviolet (UV) radiation, and atomic oxygen (AO). Of these space environmental exposure elements, AO appears to have had the greatest effect on the beta cloth. The beta cloth analyzed in this report came from the MSFC Experiment S1005 (Transverse Flat-Plate Heat Pipe) tray oriented approximately 22 deg from the leading edge vector of the LDEF satellite. The location of the tray on LDEF and the placement of the beta cloth thermal blankets are shown. The specific space environment exposure conditions for this material are listed.

Linton, Roger C.↗
NASA NTRS1998

Hydrodynamic Dryout in Two-Phase Flows: Observations of Low Bond Number Systems

Dryout occurs readily in certain slug and annular two-phase flows for systems that exhibit partial wetting. The mechanism for the ultimate rupture of the film is attributed to van der Waals forces, but the pace towards rupture is quickened by the surface tension instability (Rayleigh-type) of the annular film left by the advancing slug and by the many perturbations of the free surface present in the Re(sub g) approximately 0(10(exp 3)), Re(sub l) approximately 0(10(exp 4)), and Ca approximately 0(10(exp -1) flows. Results from low-gravity experiments using three different test fluids are presented and discussed. For the range of tests conducted, the effect of increasing viscosity is shown to eliminate the film rupture while the decrease of surface tension via a surfactant additive is shown to dramatically enhance it. Laboratory measurements using capillary tubes are presented which reveal the sensitivity of the dryout phenomena to particulate and surfactant contamination. Rom such observations, dryout due to the hydrodynamic-van der Waals instability can be expected in a certain range of flow parameters in the absence of heat transfer. The addition of heat transfer may only exacerbate the problem by producing thermal transport lines replete with "hot spots." A caution to this effect is issued to future space systems designers concerning the use of partially wetting working fluids.

Weislogel, Mark M.↗
NASA NTRSDate not supplied

Hydrogen Peroxide as a Method for Bioburden Reduction in Facilities with Strict Materials Requirements.

The cleanrooms used to curate NASA’s Astromaterials samples are carefully monitored for particulate and inorganic contamination. The clean labs also have a very limited set of acceptable materials and cleaning agents to further minimize the potential for contamination. Labs are cleaned primarily with isopropyl alcohol. Astromaterials samples are handled with tools made of stainless steel (304 or 316), Teflon, or aluminum alloy (6061). Although our current collections are not particularly susceptible to biological alteration or organic contamination, this will not be the case for new collections from the OSIRIS-REx mission, Hayabusa2, and from Mars Sample Return. Therefore, it is necessary to develop and test methods to reduce the bioburden in astromaterials cleanrooms without introducing unwanted contaminants. We will report on the results of three case studies where 7.5 wt% hydrogen peroxide was prepared from a stock solution of ultrapure 30 wt% hydrogen peroxide (JT Baker) using curation-grade ultrapure water. We followed CDC (Center for Disease Control) guidelines for using hydrogen peroxide as a high level disinfectant. This solution was used to clean a glovebox prior to processing Apollo samples, as well as surfaces in the Antarctic meteorite processing lab and Stardust lab after facilities monitoring indicated an unwanted increase in bioburden. In all three instances, the culturable bioburden was significantly reduced after a 30 min. exposure to the 7.5% hydrogen peroxide solution without a corresponding increase in inorganic or organic contamination. We observed 77 to 100% reductions in the bioburden recovery rate. In one case study, we also performed amplicon DNA sequencing on samples collected from the surfaces before and after cleaning. We observed a significant change in microbial community composition after peroxide cleaning. These results suggest that routine cleaning with hydrogen peroxide could be an effective way to control bioburden in astromaterials cleanrooms and other facilities with strict contamination control requirements.

A B Regberg↗
NASA NTRSDate not supplied

Hydrogen Peroxide as a Method for Bioburden Reduction in Facilities with Strict Materials Requirements

The cleanrooms used to curate NASA’s Astromaterials samples are carefully monitored for particulate and inorganic contamination. The clean labs also have a very limited set of acceptable materials and cleaning agents to further minimize the potential for contamination. Labs are cleaned primarily with isopropyl alcohol. Astromaterials samples are handled with tools made of stainless steel (304 or 316), Teflon, or aluminum alloy (6061). Although our current collections are not particularly susceptible to biological alteration or organic contamination, this will not be the case for new collections from the OSIRIS-REx mission, Hayabusa2, and from Mars Sample Return. Therefore, it is necessary to develop and test methods to reduce the bioburden in astromaterials cleanrooms without introducing unwanted contaminants. We will report on the results of three case studies where 7.5 wt% hydrogen peroxide was prepared from a stock solution of ultrapure 30 wt% hydrogen peroxide (JT Baker) using curation-grade ultrapure water. We followed CDC (Center for Disease Control) guidelines for using hydrogen peroxide as a high level disinfectant. This solution was used to clean a glovebox prior to processing Apollo samples, as well as surfaces in the Antarctic meteorite processing lab and Stardust lab after facilities monitoring indicated an unwanted increase in bioburden. In all three instances, the culturable bioburden was significantly reduced after a 30 min. exposure to the 7.5% hydrogen peroxide solution without a corresponding increase in inorganic or organic contamination. We observed 77 to 100% reductions in the bioburden recovery rate. In one case study, we also performed amplicon DNA sequencing on samples collected from the surfaces before and after cleaning. We observed a significant change in microbial community composition after peroxide cleaning. These results suggest that routine cleaning with hydrogen peroxide could be an effective way to control bioburden in astromaterials cleanrooms and other facilities with strict contamination control requirements.

A B Regberg↗