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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 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS2000

The ultraviolet environment of Mars: biological implications past, present, and future

A radiative transfer model is used to quantitatively investigate aspects of the martian ultraviolet radiation environment, past and present. Biological action spectra for DNA inactivation and chloroplast (photosystem) inhibition are used to estimate biologically effective irradiances for the martian surface under cloudless skies. Over time Mars has probably experienced an increasingly inhospitable photobiological environment, with present instantaneous DNA weighted irradiances 3.5-fold higher than they may have been on early Mars. This is in contrast to the surface of Earth, which experienced an ozone amelioration of the photobiological environment during the Proterozoic and now has DNA weighted irradiances almost three orders of magnitude lower than early Earth. Although the present-day martian UV flux is similar to that of early Earth and thus may not be a critical limitation to life in the evolutionary context, it is a constraint to an unadapted biota and will rapidly kill spacecraft-borne microbes not covered by a martian dust layer. Microbial strategies for protection against UV radiation are considered in the light of martian photobiological calculations, past and present. Data are also presented for the effects of hypothetical planetary atmospheric manipulations on the martian UV radiation environment with estimates of the biological consequences of such manipulations.

NASA Center ARC↗
NASA NTRS1994

Planetary entry experiments

The final report summarizes the results from three research areas: (1) window design for the radiometric measurement of the forebody radiative heating experienced by atmospheric entry spaceraft; (2) survey of the current understanding of chemical species on selected solar system bodies and assess the importance of measurements with regard to vehicle environment and with regard to understanding of planetary atmospheres with emphasis on Venus, Mars, and Titan; and (3) measure and analyze the radiation (VUV to near-IR) from the shock heated gas cap of a blunt body in an Ames arc Jet wind-tunnel facility.

Craig, Roger A.↗
NASA NTRS2018

NASA Ames' COSmIC Laboratory Astrophysics Facility: Recent Results and Progress

The COSmIC facility was developed at NASA Ames to study interstellar, circumstellar and planetary analogs in the laboratory]. COSmIC stands for "Cosmic Simulation Chamber" and is dedicated to the study of neutral and ionized molecules and nanoparticles under the low temperature and high vacuum conditions that are required to simulate space environments. COSmIC integrates a variety of instruments that allow generating; processing and monitoring simulated space conditions in the laboratory. It is composed of a Pulsed Discharge Nozzle (PDN) expansion that generates a plasma in a free supersonic jet expansion coupled to high-sensitivity, complementary in situ diagnostic tools, used for the detection and characterization of the species present in the expansion: a Cavity Ring Down Spectroscopy (CRDS) and fluorescence spectroscopy systems for photonic detection, and a Reflectron Time-Of-Flight Mass Spectrometer (ReTOF-MS) for mass detection. Recent advances achieved in laboratory astrophysics using COSmIC will be presented, in particular in the domain of the diffuse interstellar bands (DIBs) and the monitoring, in the laboratory, of the formation of dust grains and aerosols from their gasphase molecular precursors in environments as varied as circumstellar outflows and planetary atmospheres. Plans for future laboratory experiments on cosmic molecules and grains in the growing field of laboratory astrophysics (NIR-MIR CRDS, Laser Induced Fluorescence spectra of cosmic molecule analogs and the laser induced incandescence spectra of cosmic grain analogs) will also be addressed as well as the implications of the on-going studies for astronomy.

Laboratory Astrophysics↗
NASA NTRS2018

The International Space Station Space Radiation Environment: Avionics Systems Performance in Low-Earth Orbit Single Event Effects (SEE) Environments

Single event effects (SEE) are those errors, anomalies, or failures in microelectronic devices caused by the passage of a single energetic charged particle through the device. Spacecraft SEE environments consist primarily of energetic charged particles; both primary particles originating in the natural environment and secondary particles (including secondary neutrons) produced by nuclear reactions of primary particles with spacecraft materials. The energetic charged particle components (electrons, protons, and atomic nuclei) of the spacecraft SEE environment include galactic cosmic rays (GCR), and planetary radiation belt charged particles, as well as solar energetic particle event (SPE) charged particles. The International Space Station (ISS) orbital altitude and inclination (~350 km to ~420 km at 51.6o inclination) results in a spacecraft SEE environment that varies dramatically with the location in Earth?s geomagnetic field. Geomagnetic GCR shielding diminishes with distance from the geomagnetic equator. Near + 51.6o latitude the ISS GCR environment has a high degree of similarity to the interplanetary GCR environment in cis-Lunar space.SEE environments supporting ISS avionics systems design, development, test, and verification are documented in SSP-30512, Space Station Ionizing Radiation Design Environment. Comparisons of overall ISS avionics systems in-flight performance with pre-flight verification report predictions have been previously reported and meet or exceed expectations in all cases.In this paper we report the results of more detailed investigations of the effects of geographic location, altitude, solar cycle, and shielding mass effects on the in-flight SEE performance of the ISS command and data handling system during the past 17 years. In addition, we report on the preflight testing and in-flight performance of the commercial-off-the-shelf lap top computers used on ISS. Finally, we present an assessment of ISS as an avionics SEE test and flight demonstration platform for exploration hardware destined for the cis-lunar or other inner solar system environments.

International Space Station↗
NASA NTRS1994

McIDAS-eXplorer: A version of McIDAS for planetary applications

McIDAS-eXplorer is a set of software tools developed for analysis of planetary data published by the Planetary Data System on CD-ROM's. It is built upon McIDAS-X, an environment which has been in use nearly two decades now for earth weather satellite data applications in research and routine operations. The environment allows convenient access, navigation, analysis, display, and animation of planetary data by utilizing the full calibration data accompanying the planetary data. Support currently exists for Voyager images of the giant planets and their satellites; Magellan radar images (F-MIDR and C-MIDR's, global map products (GxDR's), and altimetry data (ARCDR's)); Galileo SSI images of the earth, moon, and Venus; Viking Mars images and MDIM's as well as most earth based telescopic images of solar system objects (FITS). The NAIF/JPL SPICE kernels are used for image navigation when available. For data without the SPICE kernels (such as the bulk of the Voyager Jupiter and Saturn imagery and Pioneer Orbiter images of Venus), tools based on NAIF toolkit allow the user to navigate the images interactively. Multiple navigation types can be attached to a given image (e.g., for ring navigation and planet navigation in the same image). Tools are available to perform common image processing tasks such as digital filtering, cartographic mapping, map overlays, and data extraction. It is also possible to have different planetary radii for an object such as Venus which requires a different radius for the surface and for the cloud level. A graphical user interface based on Tel-Tk scripting language is provided (UNIX only at present) for using the environment and also to provide on-line help. It is possible for end users to add applications of their own to the environment at any time.

Limaye, Sanjay S.↗
NASA NTRS1971

Planetary quarantine: Principles, methods, and problems.

Microbial survival in deep space environment, contamination of planets by nonsterile flight hardware, and hazards of back contamination are among the topics covered in papers concerned with the analytical basis for planetary quarantine. The development of the technology and policies of planetary quarantine is covered in contributions on microbiologic assay and sterilization of space flight hardware and control of microbial contamination. A comprehensive subject index is included. Individual items are abstracted in this issue.

Hall, L. B.↗
NASA NTRS1980

Infrared heterodyne spectroscopy in astronomy

A heterodyne spectrometer was constructed and applied to problems in infrared astronomical spectroscopy. The instrument offers distinct observational advantages for the detection and analysis of individual spectral lines at Doppler-limited resolution. Observations of carbon dioxide in planetary atmospheres and ammonia in circumstellar environments demonstrate the substantial role that infrared heterodyne techniques will play in the astronomical spectroscopy of the future.

Betz, A.↗
NASA NTRS1987

Mission analysis and phased development of a lunar base

Planned activities at a manned lunar base can be categorized as supporting one or more of three possible objectives: scientific research, exploitation of lunar resources for use in building a space infrastructure, or attainment of self-sufficiency in the lunar environment as a first step in planetary habitation. Scenarios constructed around each of the three goals have many common elements, particularly in the early phases. In addition, the process of constructing the scenario clearly demonstrated that later phases were critically dependent on technologies, systems, and elements developed during the early phases. The cost and the complexity of the base, as well as the structure of the Space Transportation System, are functions of the chosen long-term strategy. A real lunar base will manifest some combination of characteristics from these idealized end members.

Roberts, Barney B.↗
NASA NTRS1998

Fire Safety in Extraterrestrial Environments

Despite rigorous fire-safety policies and practices, fire incidents are possible during lunar and Martian missions. Fire behavior and hence preventive and responsive safety actions in the missions are strongly influenced by the low-gravity environments in flight and on the planetary surfaces. This paper reviews the understanding and key issues of fire safety in the missions, stressing flame spread, fire detection, suppression, and combustion performance of propellants produced from Martian resources.

Friedman, Robert↗
NASA NTRS2002

Near Infrared Emission of Highly Electronically Excited CO: A Sensitive Probe to Study the Interstellar Medium??

Among the various spectroscopic features of the second most abundant molecule in the space, CO, "the triplet - triplet transitions involving the lowest triplet state a(sup 3)II and the higher-lying a(sup 1)3 SIGMA (sup +), d(sup 3) (DELTA), e (sup 3) SIGMA (sup -) states spanning near-UV to mid-IR spectral range" have so far not been explored in astrophysical observations. The energies of these transitions are highly sensitive to the surroundings in which CO exists, i.e. gas-phase, polar or non-polar condensed phase. It is proposed here that these triplet-triplet emission/absorption bands can be used as a sensitive probe to investigate the local environments of CO, whether in the planetary atmosphere, stellar atmosphere or interstellar medium.

Gudipati, Murthy S.↗
NASA NTRS1996

Planetary atmosphere evolution: do other habitable planets exist and can we detect them?

The goal of this conference is to consider whether it is possible within the next few decades to detect Earth-like planets around other stars using telescopes or interferometers on the ground or in space. Implicit in the term "Earth-like" is the idea that such planets might be habitable by Earth-like organisms, or that they might actually be inhabited. Here, I shall address two questions from the standpoint of planetary atmosphere evolution. First, what are the chances that habitable planets exist around other stars? And, second, if inhabited planets exist, what would be the best way to detect them?.

NASA Discipline Exobiology↗
NASA NTRS1999

The global topography of Mars and implications for surface evolution

Elevations measured by the Mars Orbiter Laser Altimeter have yielded a high-accuracy global map of the topography of Mars. Dominant features include the low northern hemisphere, the Tharsis province, and the Hellas impact basin. The northern hemisphere depression is primarily a long-wavelength effect that has been shaped by an internal mechanism. The topography of Tharsis consists of two broad rises. Material excavated from Hellas contributes to the high elevation of the southern hemisphere and to the scarp along the hemispheric boundary. The present topography has three major drainage centers, with the northern lowlands being the largest. The two polar cap volumes yield an upper limit of the present surface water inventory of 3.2 to 4.7 million cubic kilometers.

Water↗
NASA NTRS2004

Environmental Test Program for the Mars Exploration Rover Project

On June 10 and July 7, 2003 the National Aeronautics and Space Administration (NASA) launched two spacecraft from Cape Canaveral, Florida for a six (6) months flight to the Red Planet, Mars. The two Mars Exploration Rover spacecraft landed safely on the planet in January 2004. Prior to the successful launch, both of the spacecraft were involved in a comprehensive test campaign that included development, qualification, and protoflight test programs. Testing was performed to simulate the environments associated with launch, inter-planetary cruise, landing on the planet and Mars surface operations. Unique test requirements included operating the spacecraft while the chamber pressure was controlled to simulate the decent to the planet from deep space, high impact landing loads and rover operations on the surface of the planet at 8 Torr and -130 C. This paper will present an overview of the test program that included vibration, pyro-shock, landing loads, acoustic noise, thermal vacuum and solar simulation testing at the Jet Propulsion Laboratory (JPL) Environmental Test Laboratory facilities in Pasadena, California.

Fisher, Terry C.↗
NASA NTRS2007

Special Issue: 4th International Workshop on Space Radiation (IWSRR)

This special issue of the journal "Radiation and Environmental Biophysics" contains 20 peer-reviewed papers contributed by leading space radiation researcher's world-wide attending the 4th IWSRR. Manuscripts cover a broad range of topics ranging from radiation environments and transport in shielding and planetary surfaces to new results in understanding the biological effects of protons and high-charge and energy (HZE) nuclei on the risk of cancer, and degenerative diseases such as central nervous system effects, heart disease, and cataracts. The issue provides a snapshot of the state-of-the-art of the research in this field, demonstrating both the important results gathered in the past few years with experiments at accelerators, and the need for more research to quantify the risk and develop countermeasures.

Cucinotta, Francis A.↗