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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

Analysis of the Atmospheric Distribution, Sources, and Sinks of Oxygenated Volatile Organic Chemicals Based on Measurements over the Pacific during TRACE-P

Airborne measurements of a large number of oxygenated volatile organic chemicals (OVOC) were carried out in the Pacific troposphere (0.1-12 km) in winter/spring of 2001 (24 February to 10 April). Specifically, these measurements included acetone (CH3COCH3), methylethyl ketone (CH3COC2H5, MEK), methanol (CH3OH), ethanol (C2H5OH), acetaldehyde (CH3CHO), propionaldehyde (C2H5CHO), peroxyacylnitrates (PANs) (C(sub n)H(sub 2n+1)COO2NO2), and organic nitrates (C(sub n)H(sub 2n+1)ONO2). Complementary measurements of formaldehyde (HCHO), methyl hydroperoxide (CH3OOH), and selected tracers were also available. OVOC were abundant in the clean troposphere and were greatly enhanced in the outflow regions from Asia. Background mixing ratios were typically highest in the lower troposphere and declined toward the upper troposphere and the lowermost stratosphere. Their total abundance (Summation of OVOC) was nearly twice that of nonmethane hydrocarbons (Summation of C2-C8 NMHC). Throughout the troposphere, the OH reactivity of OVOC is comparable to that of methane and far exceeds that of NMHC. A comparison of these data with western Pacific observations collected some 7 years earlier (February-March 1994) did not reveal significant differences. Mixing ratios of OVOC were strongly correlated with each other as well as with tracers of fossil and biomass/biofuel combustion. Analysis of the relative enhancement of selected OVOC with respect to CH3Cl and CO in 12 plumes originating from fires and sampled in the free troposphere (3-11 km) is used to assess their primary and secondary emissions from biomass combustion. The composition of these plumes also indicates a large shift of reactive nitrogen into the PAN reservoir thereby limiting ozone formation. A three-dimensional global model that uses state of the art chemistry and source information is used to compare measured and simulated mixing ratios of selected OVOC. While there is reasonable agreement in many cases, measured aldehyde concentrations are significantly larger than predicted. At their observed levels, acetaldehyde mixing ratios are shown to be an important source of HCHO (and HO x ) and PAN in the troposphere. On the basis of presently known chemistry, measured mixing ratios of aldehydes and PANs are mutually incompatible. We provide rough estimates of the global sources of several OVOC and conclude that collectively these are extremely large (150-500 Tg C / yr) but remain poorly quantified.

Singh, H. B.↗
NASA NTRS1974

ERTS program of the US Army Corps of Engineers

The Army Corps of Engineers research and development efforts associated with the ERTS Program are confined to applications of investigation, design, construction, operation, and maintenance of water resource projects. Problems investigated covered: (1) resource inventory; (2) environmental impact; (3) pollution monitoring; (4) water circulation; (5) sediment transport; (6) data collection systems; (7) engineering; and (8) model verification. These problem areas were investigated in relation to bays, reservoirs, lakes, rivers, coasts, and regions. ERTS-1 imagery has been extremely valuable in developing techniques and is now being used in everyday applications.

Jarman, J. W.↗
NASA NTRS1984

Pyrotechnic shock: A literature survey of the Linear Shaped Charge (LSC)

Linear shaped charge (LSC) literature for the past 20 years is reviewed. The following topics are discussed: (1) LSC configuration; (2) LSC usage; (3) LSC induced pyroshock; (4) simulated pyrotechnic testing; (5) actual pyrotechnic testing; (6) data collection methods; (7) data analysis techniques; (8) shock reduction methods; and (9) design criteria. Although no new discoveries have been made in LSC research, charge shapes are improved to allow better cutting performance, testing instrumentation is refined, and some new explosives, for use in LSC, are formulated.

Smith, J. L.↗
NASA NTRS1988

Extravehicular activities limitations study. Volume 1: Physiological limitations to extravehicular activity in space

This report contains the results of a comprehensive literature search on physiological aspects of EVA. Specifically, the topics covered are: (1) Oxygen levels; (2) Optimum EVA work; (3) Food and Water; (4) Carbon dioxide levels; (5) Repetitive decompressions; (6) Thermal, and (7) Urine collection. The literature was assessed on each of these topics, followed by statements on conclusions and recommended future research needs.

Furr, Paul A.↗
NASA NTRS1990

Refraction near the horizon

Variations in astronomical refraction near the horizon are examined. Sunset timings, a sextant mounted on a tripod, and a temperature profile are utilized to derive the variations in refraction data, collected from 7 locations. It is determined that the refraction ranges from 0.234 to 1.678 deg with an rms deviation of 0.16, and it is observed that the variation is larger than previously supposed. Some applications for the variation of refraction value are discussed.

Schaefer, Bradley E.↗
NASA NTRS1990

Compositional range in the Canyon Diablo meteoroid

The compositional range within the Canyon Diablo (CD) iron meteorites associated with the formation of the Meteor Crater (Arizona) was examined, using the INAA to analyze a set of CD samples consisting of nine irons collected within 7 km of the Meteor Crater, four Arizona IAB irons that were identified by Wasson (1968) as transported CD fragments, and irons from Las Vegas (Nevada) and Moab (Utah) that Buchwald (1975) suggested to be transported CD fragments. Results show that the irons named Helt Township, Idaho, Las Vegas, Mamaroneck, Moab, and Pulaski County are, most likely, mislabeled CD specimens. On the other hand, meteorites named Alexander County, Allan Hills A77283, Ashfork, Fairfield, and Rifle are identified as compositionally distinct independent falls.

Wasson, John T.↗
NASA NTRS2000

TES Observations of the Martian Surface and Atmosphere

The Thermal Emission Spectrometer (TES) instrument is a Fourier transform Michelson interferometer operating with 10 or 5 cm(exp -1) sampling in the thermal infrared spectral region from 1700 to 200 cm(exp -1) (-6 to 50 micrometers) where virtually all minerals have characteristic fundamental vibrational absorption bands. The TES data used in this paper are among the 6 x 10(exp 7) spectra collected during the early mapping phase of the Mars Global Surveyor (MGS) mission from southern hemisphere winter to early summer (aerocentric longitude, L(sub s), 107 deg to 297 deg. The methodology for separating the surface and atmospheric components of the radiance from Mars, which allows detailed analysis and interpretation of surface mineralogy, is described in previous paper. Additional information is contained in original extended abstract.

Christensen, P. R.↗
NASA NTRS2004

Comparison of Landsat-7 Enhanced Thematic Mapper Plus (ETM+) and Earth Observing One (EO-1) Advanced Land Imager

We compare images from the Enhanced Thematic Mapper Plus (ETM+) sensor on Landsat-7 and the Advanced Land Imager (ALI) instrument on Earth Observing One (EO-1) over a test site in Rochester, New York. The site contains a variety of features, ranging from water of varying depths, deciduous/coniferous forest, and grass fields, to urban areas. Nearly coincident cloud-free images were collected one minute apart on 25 August 2001. We also compare images of a forest site near Howland, Maine, that were collected on 7 September, 2001. We atmospherically corrected each pair of images with the Second Simulation of the Satellite Signal in the Solar Spectrum (6S) atmosphere model, using aerosol optical thickness and water vapor column density measured by in situ Cimel sun photometers within the Aerosol Robotic Network (AERONET), along with ozone density derived from the Total Ozone Mapping Spectrometer (TOMS) on the Earth Probe satellite. We present true-color composites from each instrument that show excellent qualitative agreement between the multispectral sensors, along with grey-scale images that demonstrate a significantly improved ALI panchromatic band. We quantitatively compare ALI and ETM+ reflectance spectra of a grassy field in Rochester and find < or equal to 6% differences in the visible/near infrared and approx. 2% differences in the short wave infrared. Spectral comparisons of forest sites in Rochester and Howland yield similar percentage agreement except for band 1, which has very low reflectance. Principal component analyses and comparison of normalized difference vegetation index histograms for each sensor indicate that the ALI is able to reproduce the information content in the ETM+ but with superior signal-to-noise performance due to its increased 12-bit quantization.

Pedelty, Jeffrey A.↗
NASA NTRS2004

Measurements of HNO3, SO2 High Resolution Aerosol SO4 (sup 2-), and Selected Aerosol Species Aboard the NASA DC-8 Aircraft: During the Transport and Chemical Evolution Over the Pacific Airborne Mission (TRACE-P)

The UNH investigation during TRACE-P provided measurements of selected acidic gases and aerosol species aboard the NASA DC-8 research aircraft. Our investigation focused on measuring HNO3, SO2, and fine (less than 2 microns) aerosol SO4(sup 2-) with two minute time resolution in near-real-time. We also quantified mixing ratios of aerosol ionic species, and aerosol (210)Pb and (7)Be collected onto bulk filters at better than 10 minute resolution. This suite of measurements contributed extensively to achieving the principal objectives of TRACE-P. In the context of the full data set collected by experimental teams on the DC-8, our observations provide a solid basis for assessing decadal changes in the chemical composition and source strength of Asian continental outflow. This region of the Pacific should be impacted profoundly by Asian emissions at this time with significant degradation of air quality over the next few decades. Atmospheric measurements in the western Pacific region will provide a valuable time series to help quantify the impact of Asian anthropogenic activities. Our data also provide important insight into the chemical and physical processes transforming Asian outflow during transport over the Pacific, particularly uptake and reactions of soluble gases on aerosol particles. In addition, the TRACE-P data set provide strong constraints for assessing and improving the chemical fields simulated by chemical transport models.

Talbot, Robert W.↗
NASA NTRS2005

EOSDIS Petabyte Archives: Tenth Anniversary

One of the world s largest scientific data systems, NASA'S Earth Observing System Data and Information System (EOSDIS) has stored over three petabytes of earth science data in a geographically distributed mass storage system. Design for this system began in the early 1990s and included a presentation of the design of the mass storage system at this conference in 1995. Many changes have occurred in the ten years since that presentation, much of it performed while the system was operational. In its first operational year (2000), the EOSDIS system had increased NASA's collection of earth science data holdings eight-fold. Today, EOSDIS collects over 7,000 gigabytes of data per week, almost 60 times more than the Hubble Space Telescope. This load represents major challenges for ingest into the mass storage system, as well as for timely and balanced data distribution out of the mass storage system. This paper discusses the evolution of the EOSDIS focusing primarily on the mass storage system component of the archive. We present the lessons that were learned over the years and some directions that we are taking for the future.

Behnke, Jeanne↗
NASA NTRS2007

Status of the NASA Robotic Mission Conjunction Assessment Effort

This viewgraph presentation discusses NASA's processes and tools used to mitigate threats to NASA's robotic assets. The topics include: 1) Background; 2) Goddard Stakeholders and Mission Support; 3) ESC and TDRS Mission Descriptions; 4) TDRS Conjunction Assessment Process; 5) ESMO Conjunction Assessment Process; 6) Recent Operations Experiences; 7) Statistics Collected for ESC Regime; and 8) Current and Future Analysis Items.

Newman, Lauri Kraft↗
NASA NTRS2007

An Overview of the Mars Reconnaissance Orbiter (MRO) Science Mission

The Mars Reconnaissance Orbiter (MRO) is the latest addition to the suite of missions on or orbiting Mars as part of the NASA Mars Exploration Program. Launched on 12 August 2005, the orbiter successfully entered Mars orbit on 10 March 2006 and finished aerobraking on 30 August 2006. Now in its near-polar, near-circular, low-altitude (approximately 300 km), 3 p.m. orbit, the spacecraft is operating its payload of six scientific instruments throughout a one-Mars-year Primary Science Phase (PSP) of global mapping, regional survey, and targeted observations. Eight scientific investigations were chosen for MRO, two of which use either the spacecraft accelerometers or tracking of the spacecraft telecom signal to acquire data needed for analysis. Six instruments, including three imaging systems, a visible-near infrared spectrometer, a shallow-probing subsurface radar, and a thermal-infrared profiler, were selected to complement and extend the capabilities of current working spacecraft at Mars. Whether observing the atmosphere, surface, or subsurface, the MRO instruments are designed to achieve significantly higher resolution while maintaining coverage comparable to the current best observations. The requirements to return higher-resolution data, to target routinely from a low-altitude orbit, and to operate a complex suite of instruments were major challenges successfully met in the design and build of the spacecraft, as well as by the mission design. Calibration activities during the seven-month cruise to Mars and limited payload operations during a three-day checkout prior to the start of aerobraking demonstrated, where possible, that the spacecraft and payload still had the functions critical to the science mission. Two critical events, the deployment of the SHARAD radar antenna and the opening of the CRISM telescope cover, were successfully accomplished in September 2006. Normal data collection began 7 November 2006 after solar conjunction. As part of its science mission, MRO will also aid identification and characterization of the most promising sites for future landed missions, both in terms of safety and in terms of the scientific potential for future discovery. Ultimately, MRO data will advance our understanding of how Mars has evolved and by which processes that change occurs, all within a framework of identifying the presence, extent, and role of water in shaping the planet s climate over time.

astronomical instruments↗
NASA NTRS2009

Validation of Cardiovascular Parameters during NASA's Functional Task Test

Microgravity exposure causes physiological deconditioning and impairs crewmember task performance. The Functional Task Test (FTT) is designed to correlate these physiological changes to performance in a series of operationally-relevant tasks. One of these, the Recovery from Fall/Stand Test (RFST), tests both the ability to recover from a prone position and cardiovascular responses to orthostasis. PURPOSE: Three minutes were chosen for the duration of this test, yet it is unknown if this is long enough to induce cardiovascular responses similar to the operational 5 min stand test. The purpose of this study was to determine the validity and reliability of heart rate variability (HRV) analysis of a 3 min stand and to examine the effect of spaceflight on these measures. METHODS: To determine the validity of using 3 vs. 5 min of standing to assess HRV, ECG was collected from 7 healthy subjects who participated in a 6 min RFST. Mean R-R interval (RR) and spectral HRV were measured in minutes 0-3 and 0-5 following the heart rate transient due to standing. Significant differences between the segments were determined by a paired t-test. To determine the reliability of the 3-min stand test, 13 healthy subjects completed 3 trials of the FTT on separate days, including the RFST with a 3 min stand. Analysis of variance (ANOVA) was performed on the HRV measures. One crewmember completed the FTT before a 14-day mission, on landing day (R+0) and one (R+1) day after returning to Earth. RESULTS VALIDITY: HRV measures reflecting autonomic activity were not significantly different during the 0-3 and 0-5 min segments. RELIABILITY: The average coefficient of variation for RR, systolic (SBP) and diastolic blood pressures during the RFST were less than 8% for the 3 sessions. ANOVA results yielded a greater inter-subject variability (p<0.006) than inter-session variability (p>0.05) for HRV in the RFST. SPACEFLIGHT: Lower RR and higher SBP were observed on R+0 in rest and stand. On R+1, both RR and SBP trended towards preflight rest and stand values. Postflight HRV showed higher LF/HF for rest and stand and lower HFnu during rest. CONCLUSION: These studies show that a 3 min stand delivers repeatable HRV data in the context of this larger series of FTT tests. Spaceflight-induced changes in blood pressure, RR and autonomic function (HRV) are evident from the RFST.

Arzeno, N. M.↗
NASA NTRSDate not supplied

Altered Immune Differentials Between Male and Female Mice Independent of Ionizing Irradiation

As upcoming exploratory missions to the Lunar surface and Mars during the Artemis Program will send both female and male crewmembers, studies identifying sex-specific effects are necessary. It is well-documented that the immune system engages different responses between females and males following exposures to infectious challenge, tumors surveillance, and autoimmune development. Yet, the immune effects of spaceflight-like exposures between the sexes are limited. Therefore, this study sought to address the effects of spaceflight-like conditions on immune differentials in female and male mice. We hypothesized that the spaceflight factor, ionizing radiation, will have sex-specific effects on immune differentials. To test this, singly-housed, 12-month old female and male wildtype (Wt) mice were exposed to acute ionizing gamma irradiation (50 cGy), followed by retro-orbital blood collections at 7-days post-irradiation. Leukocytes were analyzed by flow cytometry characterizing, granulocytes, monocytes, lymphocytes (cytotoxic/helper T cells and B cells), neutrophils, eosinophils, and NK/NKT cells. Briefly, minimal sex-specific effects were observed across the cell types listed at this time point, including changes in granulocyte and lymphocyte populations. The results revealed females displayed elevated granulocytes and reduced lymphocytes compared to their male counterparts, independent of irradiation exposure. These results suggest female mice may be more capable to produce innate inflammatory mediators but may be adaptively immune compromised. In brief, this study provides insight into the sex-specific immune risks following ionizing radiation that may be experienced during spaceflight, which is relevant for future countermeasure development.

spaceflight stressors↗
NASA NTRSDate not supplied

Altered Immune Differentials Between Male and Female Mice Independent of Ionizing Irradiation

As upcoming exploratory missions to the Lunar surface and Mars during the Artemis Program will send both female and male crewmembers, studies identifying sex-specific effects are necessary. It is well-documented that the immune system engages different responses between females and males following exposures to infectious challenge, tumors surveillance, and autoimmune development. Yet, the immune effects of spaceflight-like exposures between the sexes are limited. Therefore, this study sought to address the effects of spaceflight-like conditions on immune differentials in female and male mice. We hypothesized that the spaceflight factor, ionizing radiation, will have sex-specific effects on immune differentials. To test this, singly-housed, 12-month old female and male wildtype (Wt) mice were exposed to acute ionizing gamma irradiation (50 cGy), followed by retro-orbital blood collections at 7-days post-irradiation. Leukocytes were analyzed by flow cytometry characterizing, granulocytes, monocytes, lymphocytes (cytotoxic/helper T cells and B cells), neutrophils, eosinophils, and NK/NKT cells. Briefly, minimal sex-specific effects were observed across the cell types listed at this time point, including changes in granulocyte and lymphocyte populations. The results revealed females displayed elevated granulocytes and reduced lymphocytes compared to their male counterparts, independent of irradiation exposure. These results suggest female mice may be more capable to produce innate inflammatory mediators but may be adaptively immune compromised. In brief, this study provides insight into the sex-specific immune risks following ionizing radiation that may be experienced during spaceflight, which is relevant for future countermeasure development.

spaceflight stressors↗
NASA NTRSDate not supplied

Translational Line of Sight: a multi-omics longitudinal study of the murine retinal response to spaceflight hazard analogs

The space environment includes unique hazards like radiation and microgravity which adversely affect physiology and behavior of humans and rodent models. To better characterize the retinal response to spaceflight, we assessed a multi-omics NASA GeneLab dataset where 6-month-old female mice were gamma irradiated and/or hindlimb unloaded for 21 days followed by whole transcriptome shotgun sequencing (RNA-Seq) and reduced representation bisulfite sequencing (RRBS) of retina samples collected at 7 days, 1 month or 4 months post-exposure. We compared time-matched epigenomic and transcriptomic retinal profiles revealing a total of 4,178 differentially methylated loci or regions, and 457 differentially expressed genes. Highest correlation in methylation differences was seen across different conditions at the same time point (e.g., between radiation exposure and hindlimb unloaded at 7 days). Biological processes related to nucleotide metabolism were enriched in all groups with activation at 1 month and suppression at 7 days and 4 months. Genes and processes related to Notch and Wnt signaling showed alterations 4 months post-exposure. Interestingly, Notch3 and Lrg1 showed differential patterns in the NASA Twins Study in-flight samples and in response to stressors in the murine retina in the current study. A total of 23 genes were both differentially methylated and expressed, including genes involved in retinal disease or cataract development (Crybb3, Fgfr1, Pitpnm3, Sipa1l3, Sox9) and inflammatory response (B4galt6, Ppm1a, Sphk1). To our knowledge, the current multi-omics analysis is the first multi-omics study to interrogate the epigenomic and transcriptomic impacts of radiation and hindlimb unloading on the retina in isolation and in combination. The results provide an insight into the retinal response to individual spaceflight hazard analogs and their interplay at different post-exposure stages and contributes towards a mechanistic understanding of spaceflight-induced vision impairment using ground-based models.

Prachi Kothiyal↗
NASA NTRSDate not supplied

A Multi-omics Longitudinal Study of the Murine Retinal Response to Chronic Low-dose Irradiation and/or Simulated Microgravity

The space environment includes unique hazards like radiation and microgravity which adversely affect physiology and behavior of humans and rodent models. To better characterize the retinal response to spaceflight, we assessed a multi-omics NASA GeneLab dataset where 6-month-old female mice were gamma irradiated and/or hindlimb unloaded for 21 days followed by whole transcriptome shotgun sequencing (RNA-Seq) and reduced representation bisulfite sequencing (RRBS) of retina samples collected at 7 days, 1 month or 4 months post-exposure. We compared time-matched epigenomic and transcriptomic retinal profiles revealing a total of 4,178 differentially methylated loci or regions, and 457 differentially expressed genes. Highest correlation in methylation differences was seen across different conditions at the same time point (e.g., between radiation exposure and hindlimb unloaded at 7 days). Biological processes related to nucleotide metabolism were enriched in all groups with activation at 1 month and suppression at 7 days and 4 months. Genes and processes related to Notch and Wnt signaling showed alterations 4 months post-exposure. Interestingly, Notch3 and Lrg1 showed differential patterns in the NASA Twins Study in-flight samples and in response to stressors in the murine retina in the current study. A total of 23 genes were both differentially methylated and expressed, including genes involved in retinal disease or cataract development (Crybb3, Fgfr1, Pitpnm3, Sipa1l3, Sox9) and inflammatory response (B4galt6, Ppm1a, Sphk1). To our knowledge, the current multi-omics analysis is the first multi-omics study to interrogate the epigenomic and transcriptomic impacts of radiation and hindlimb unloading on the retina in isolation and in combination. The results provide an insight into the retinal response to individual spaceflight hazard analogs and their interplay at different post-exposure stages and contributes towards a mechanistic understanding of spaceflight-induced vision impairment using ground-based models.

Prachi Kothiyal↗