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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

MSFC Skylab contamination control systems mission evaluation

Cluster external contamination control evaluation was made throughout the Skylab Mission. This evaluation indicated that contamination control measures instigated during the design, development, and operational phases of this program were adequate to reduce the general contamination environment external to the Cluster below the threshold senstivity levels for experiments and affected subsystems. Launch and orbit contamination control features included eliminating certain vents, rerouting vents for minimum contamination impact, establishing filters, incorporating materials with minimum outgassing characteristics and developing operational constraints and mission rules to minimize contamination effects. Prior to the launch of Skylab, contamination control math models were developed which were used to predict Cluster surface deposition and background brightness levels throughout the mission. The report summarizes the Skylab system and experiment contamination control evaluation. The Cluster systems and experiments evaluated include Induced Atmosphere, Corollary and ATM Experiments, Thermal Control Surfaces, Solar Array Systems, Windows and Star Tracker.

Source record↗
DOE OSTI2024

"Soiling, Cleaning, and Abrasion: The Results of the Five-Year Photovoltaic Glass Coating Field Study" [Slides]

External contamination ("soiling") of the incident surface is a major limiting factor for solar technologies. A 5-year field glass coupon study was conducted to better understand external contamination and its effects; compare cleaning methods and the use of preventative coatings; and explore the abrasion resulting from cleaning to advise on accelerated abrasion testing. Test sites included the cities of Dubai (UAE), Kuwait City (Kuwait), Mesa (AZ), Mumbai (India), and Sacramento (CA). Through the 5-year cumulative study, dry brush, water spray, and wet sponge and squeegee cleaning methods were compared to no cleaning. Optical microscopy was used to obtain images, including representative color images, grayscale images for object analysis, and oblique images for coating integrity assessment. A thresholding protocol was developed to analyze and distinguish specimens using the ImageJ software. Optical performance was quantified using a spectrophotometer, including comprehensive optical characterization (transmittance, reflectance, and absorptance in addition to forward- and back-scattering). Atomic force microscopy was used to verify the abrasion damage morphology, including the width and depth of surface scratches. Analysis of the results included correlation of optical performance and particle area coverage, rank order (by coating or location), and the acceleration factor for abrasion damage. The efficacy of external cleaning was more readily distinguished from the effectiveness of antisoiling coatings. The acceleration factor for dry brush cleaning of a porous silica coating was found to be on the order of unity.

14 SOLAR ENERGY↗
NASA NTRS1990

Spacecraft external molecular contamination analysis

Control of contamination on and around spacecraft is required to avoid adverse effects on the performance of instruments and spacecraft systems. Recent work in this area is reviewed and discussed. Specific issues and limitations to be considered as part of the effort to predict contamination effects using modeling techniques are addressed. Significant results of Space Shuttle missions in the field of molecule/surface interactions as well as their implications for space station design and operation are reviewed.

Ehlers, H. K. F.↗
NASA NTRS1991

MOLFLUX analysis of the SSF electrical power system contamination

The external induced contamination of Space Station Freedom's electrical power system surfaces is assessed using a molecular flow evaluation code, MOLFLUX. Outgassing rates are compared to available experimental data, and deposition to the midregion of both the solar array and the photovoltaic power module thermal control system radiator is calculated using a constant sticking coefficient. An estimate of annual deposition to the solar array due to outgassing is found to be 10 percent of the Space Station Freedom program requirement for maximum allowable deposition, while annual deposition to the radiator is approximately equal to the requirement.

Cognion, Rita L.↗
NASA NTRS1983

Abatement of gaseous and particulate contamination in a space instrument

Methods to prevent the ingestion of external contaminants into the instrument and to limit the effect of the self-generated contaminants during ground, launch, orbiting and landing phases of flight were investigated. It is proposed that a positive pressure and purging flow of clean gas inside the instrument be maintained while on the ground, during launch, and for a period of time in orbit. The pressure to be maintained and the required purging flow are examined in terms of the effectiveness in preventing gaseous and particulate contaminants ingestion and the abatement of the self-generated contaminants. Considerations have been given to the venting requirements for the structural integrity of the instrument during launch, the limitations on the volume and the pressure of the purging gas to be carried along in orbit, and the required venting area is established based on the internal volume of the instrument, the allowable pressure differential, and the rate of external pressure change during launch. Previously announced in STAR as N83-23350

Scialdone, J. J.↗
NASA NTRSDate not supplied

International Space Station Space Environments Performance and Anomaly Resolution

The International Space Station is the largest and most complex on-orbit platform for space science utilization in low Earth orbit. The Space Environments Team addresses natural and induced environments for the ISS Program including external contamination, ionizing radiation, neutral atmosphere and solar ultraviolet radiation, plasma effects, and acoustics. For the ISS to fulfill its mission as a long-duration science platform, space environments effects are assessed, monitored, and controlled through design or operational mitigation. Interactions of ISS hardware with the natural and induced space environments, and the assessment and mitigation of those effects play a critical role in ISS mission operations. The Space Environments Team has complete system integration responsibility in these area for U.S./International Partner/Russian hardware, visiting vehicles, ISS payloads and operation. Lessons learned and processes developed for ISS are applicable to the design, assembly, and operations of long-duration space systems.

space environments↗
NASA NTRS1983

Abatement of gaseous and particulate contamination in a space instrument application to a solar telescope

Methods to prevent the ingestion of external contaminants into the instrument and to limit the effect of the self-generated contaminants during ground, launch, orbiting and landing phases of flight were investigated. It is proposed that a positive pressure and purging flow of clean gas inside the instrument be maintained while on the ground, during launch, and for a period of time in orbit. The pressure to be maintained and the required purging flow are examined in terms of the effectiveness in preventing gaseous and particulate contaminants ingestion and the abatement of the self-generated contaminants. Considerations have been given to the venting requirements for the structural integrity of the instrument during launch, the limitations on the volume and the pressure of the purging gas to be carried along in orbit, and the required venting area is established based on the internal volume of the instrument, the allowable pressure differential, and the rate of external pressure change during launch.

Scialdone, J. J.↗
NASA NTRS1991

Theoretical and experimental studies relevant to interpretation of auroral emissions

The accomplishments achieved over the past year are detailed with emphasis on the interpretation or auroral emissions and studies of potential spacecraft-induced contamination effects. Accordingly, the research was divided into two tasks. The first task is designed to add to the understanding of space vehicle induced external contamination. An experimental facility for simulation of the external environment for a spacecraft in low earth orbit was developed. The facility was used to make laboratory measurements of important phenomena required for improving the understanding of the space vehicle induced external environment and its effect on measurement of auroral emissions from space-based platforms. A workshop was sponsored to provide a forum for presentation of the latest research by nationally recognized experts on space vehicle contamination and to discuss the impact of this research on future missions involving space-based platforms. The second task is to add an ab initio auroral calculation to the extant ionospheric/thermospheric global modeling capabilities. Once the addition of the code was complete, the combined model was to be used to compare the relative intensities and behavior of various emission sources (dayglow, aurora, etc.). Such studies are essential to an understanding of the types of vacuum ultraviolet (VUV) auroral images which are expected to be available within two years with the successful deployment of the Ultraviolet Imager (UVI) on the ISTP POLAR spacecraft. In anticipation of this, the second task includes support for meetings of the science working group for the UVI to discuss operational and data analysis needs. Taken together, the proposed tasks outline a course of study designed to make significant contributions to the field of space-based auroral imaging.

Keffer, Charles E.↗
NASA NTRS2020

SAGE III ISS Contamination Monitoring Package: Observations in Orbit

The Stratospheric Aerosol and Gas Experiment III (SAGE III) telescope and instrument assembly employ the methods of solar occultation and lunar occultation to retrieve near-global vertical profiles of atmospheric ozone, water vapor, nitrogen dioxide, aerosol extinctions, and other gaseous species and atmospheric state parameters. The SAGE III grating spectrometer measures light within the spectral range of 280 nm to 1037 nm at approximately 1 nm resolution, but retrievals in the Ultraviolet (UV) are particularly sensitive to contamination of the optical train. Therefore, a contamination door that contains a quartz optical window can be closed over the telescope aperture during periods of enhanced external contaminant flux. This optically transparent window permits continued science event acquisition at an acceptably diminished signal-to-noise ratio, which is expected to decline with ongoing accretion of contaminant material. To date, this impact has been short term, and science quality through the window returns to baseline performance after a contamination source is removed and spontaneous desorption removes material from the low-affinity quartz surface. Two Contamination Monitoring Packages (CMPs) consisting of eight Thermoelectric Quartz Crystal Microbalances (TQCMs) from QCM Research provide characterization and redundant monitoring of contaminant deposition from the 2π steradian solid angle on the payload side of the Expedite the Processing of Experiments to the Space Station (ExPRESS) Payload Adapter. CMP data are closely examined by the SAGE III team to determine when the contamination door should remain closed during science events and in what direction the instrument assembly scan head should stow when not acquiring science measurements. Additionally, should the CMPs indicate an unacceptable accretion rate, the ight computer will close the contamination door as part of the automatic fault detection system. Along with spectrometer measurements of the quartz window's transmission, the payload CMPs enable auditing of the mission contamination budget. The process of Thermogravimetric Analysis (TGA) can be used to help identify chemical constituents accreted on the CMP sensors. To be presented here along with an explanation of the CMP systems are the first two and a half years of observations of the contaminant deposition environment around the payload in quiescence and during special events like docking vehicles.

Tyler T Dawson↗
NASA NTRS2020

SAGE III/ISS Contamination Monitoring Package: Observations in Orbit

The Stratospheric Aerosol and Gas Experiment III (SAGE III) telescope and instrument assembly employ the methods of solar occultation and lunar occultation to retrieve near-global vertical profiles of atmospheric ozone, water vapor, nitrogen dioxide, aerosol extinctions, and other gaseous species and atmospheric state parameters. The SAGE III grating spectrometer measures light within the spectral range of 280 nm to 1037 nm at approximately 1 nm resolution, but retrievals in the Ultraviolet (UV) are particularly sensitive to contamination of the optical train. Therefore, a contamination door that contains a quartz optical window can be closed over the telescope aperture during periods of enhanced external contaminant flux. This optically transparent window permits continued science event acquisition at an acceptably diminished signal-to-noise ratio, which is expected to decline with ongoing accretion of contaminant material. To date, this impact has been short term, and science quality through the window returns to baseline performance after a contamination source is removed and spontaneous desorption removes material from the low-affinity quartz surface. Two Contamination Monitoring Packages (CMPs) consisting of eight Thermoelectric Quartz Crystal Microbalances (TQCMs) from QCM Research provide characterization and redundant monitoring of contaminant deposition from the 2pi steradian solid angle on the payload side of the Expedite the Processing of Experiments to the Space Station (ExPRESS) Payload Adapter. CMP data are closely examined by the SAGE III team to determine when the contamination door should remain closed during science events and in what direction the instrument assembly scan head should stow when not acquiring science measurements. Additionally, should the CMPs indicate an unacceptable accretion rate, the flight computer will close the contamination door as part of the automatic fault detection system. Along with spectrometer measurements of the quartz window's transmission, the payload CMPs enable auditing of the mission contamination budget. The process of Thermogravimetric Analysis (TGA) can be used to help identify chemical constituents accreted on the CMP sensors. To be presented here along with an explanation of the CMP systems are the first two and a half years of observations of the contaminant deposition environment around the payload in quiescence and during special events like docking vehicles.

Tyler T Dawson↗
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 NTRS1995

The Wide Field/Planetary Camera 2 (WFPC-2) molecular adsorber

A device has been developed at the Jet Propulsion Laboratory, California Institute of Technology, for the adsorption of contaminants inside a space instrument during flight. The molecular adsorber was developed for use on the Wide Field Planetary Camera 2, and it has been shown to perform at its design specifications in the WFPC-2. The basic principle of the molecular adsorber is a zeolite-coated ceramic honeycomb. The arrangement is efficient for adsorption and also provides the needed rigidity to retain the special zeolite coating during the launch vibrational environment. The adsorber, on other forms, is expected to be useful for all flight instruments sensitive to internal sources of contamination. Typically, some internal contamination is unavoidable. A common design solution is to increase the venting to the exterior. However, for truly sensitive instruments, the external contamination environment is more severe. The molecular adsorber acts as a one-way vent to solve this problem. Continued development is planned for this device.

Barengoltz, Jack↗
NASA NTRS1987

Contamination assessment for OSSA space station IOC payloads

The results are presented from a study for the Space Station Planners Group of the Office of Space Sciences and Applications. The objectives of the study are: (1) the development of contamination protection requirements for protection of Space Station attached payloads, serviced payloads and platforms; and (2) the determination of unknowns or major impacts requiring further assessment. The nature, sources, and quantitative properties of the external contaminants to be encountered on the Station are summarized. The OSSA payload contamination protection requirements provided by the payload program managers are reviewed and the level of contamination awareness among them is discussed. Preparation of revisions to the contamination protection requirements are detailed. The comparative impact of flying the Station at constant atmospheric density rather than constant altitude is assessed. The impact of the transverse boom configuration of the Station on contamination is also assessed. The contamination protection guidelines which OSSA should enforce during their development of payloads are summarized.

Chinn, S.↗
NASA NTRS1988

Contamination control requirements document JSC 30426 recommended updates

Contamination control requirements for the Space Station have been evolving over the last few years. Workshops, comments by experimenters and continuing analysis have resulted in recommending changes to the November 19, 1986 version of Space Station External Contamination Control Requirements, JSC 30426. These are summarized and presented, so that the requirements can be revised as soon as possible, to minimize costly design impacts on the Space Station.

Rantanen, Ray↗
NASA NTRS1998

The Passive Optical Sample Assembly (POSA): I Experiment: First Flight Results and Conclusions

The Passive Optical Sample Assembly-I (POSA-I), part of the Mir Environmental Effects Payload (MEEP), was designed to study the combined effects of contamination, atomic oxygen, ultraviolet radiation, vacuum, thermal cycling, and other constituents of the space environment on spacecraft materials. The MEEP program is a Phase 1 International Space Station Risk Mitigation Experiment. SSP 30258 "Thermal Control Architectural Control Document", section 3.1.2 requires that International Space Station (ISS) external materials meet performance requirements when exposed to the external environment as defined in SSP 30426, "Space Station External Contamination Control Requirements." Contamination control documents call for less than 3 x 10(exp -7) gm/sq cm/yr of molecular contamination on a surface at 300 K at the Prime Measurement Points during quiescent periods and less than 1 x 10(exp-6) gm/sq cm/yr during non-quiescent periods. Assuming a density of 1.0 g/cu cm for the contaminant, this is roughly equivalent to 30-100 A per year. A previous Mir flight experiment (Guillaumon et al. 1991) measured 321-716 A per year. Were this to happen on ISS, the radiators would reach end-of-life properties much sooner than the planned 10 years. Therefore, POSA was proposed to expose ISS-baselined materials (such as Z93 white thermal control paint and chromic acid anodized aluminum) to the Mir environment and determine not only the level of contamination from an orbiting, active space station but also the effect of contamination on thermal optical properties. POSA-I consisted of nearly 400 samples of various candidate materials for ISS. Paint samples flown included Z-93 and YB-71 white thermal control paints and a new inorganic bright yellow paint htat can be utilized for astronaut visual aids.

Zwiener, James M.↗
NASA NTRS1987

Space Station users contamination requirements

An account is given of the contamination sensitivities and requirements of various planned NASA Space Station users in all science categories, as well as the methods by which the Space Station will accomodate these requirements in the cases of attached payloads, core station-attached payloads, and platform payloads. Attention is given to the Space Station's external contamination environment, the degree of protection from contamination that the Space Station user must provide, the amount of warning users will receive prior to the initiation of potentially contamination-generating activities in the Space Station, and different contamination probabilities for the various parts of the Space Station.

Carosso, Nancy J. P.↗