Survey of extraterrestrial non-solar X-radiation by rocket borne instruments Final report
Survey of extraterrestrial nonsolar X-radiation by Aerobee rocket measurements
X-RAY↗
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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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Amino Acids from Icy Amines: A Radiation-Chemical Approach to Extraterrestrial Synthesis
Detections of amino acids in meteorites go back several decades, with at least 100 such compounds being reported for the Murchison meteorite alone. The presence of these extraterrestrial molecules raises questions as to their formation, abundance, thermal stability, racemization, and possible subsequent reactions. Although all of these topics have been studied in laboratories, such work often involves many variables and unknowns. This has led us to seek out model systems with which to uncover reaction products, test chemical predictions, and sited light on underlying reaction mechanisms. This presentation will describe one such study, focusing on amino-acid formation in ices.
Dworkin, J. P.↗
Radiation analysis for manned missions to the Jupiter system
An analysis for manned missions targeted to the Jovian system has been performed in the framework of the NASA RASC (Revolutionary Aerospace Systems Concepts) program on Human Exploration beyond Mars. The missions were targeted to the Jupiter satellite Callisto. The mission analysis has been divided into three main phases, namely the interplanetary cruise, the Jupiter orbital insertion, and the surface landing and exploration phases. The interplanetary phase is based on departure from the Earth-Moon L1 point. Interplanetary trajectories based on the use of different propulsion systems have been considered, with resulting overall cruise phase duration varying between two and five years. The Jupiter-approach and the orbital insertion trajectories are considered in detail, with the spacecraft crossing the Jupiter radiation belts and staying around the landing target. In the surface exploration phase the stay on the Callisto surface is considered. The satellite surface composition has been modeled based on the most recent results from the GALILEO spacecraft. In the transport computations the surface backscattering has been duly taken into account. Particle transport has been performed with the HZETRN heavy ion code for hadrons and with an in-house developed transport code for electrons and bremsstrahlung photons. The obtained doses have been compared to dose exposure limits. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.
NASA Center LaRC↗
Reflection Spectra as a Basis for Studying Extraterrestrial Life Semiannual Report, May 1 - Oct. 31, 1966
Planetary reflection spectroscopy for studying extraterrestrial life
PLANETARY RADIATION↗
Galactic Noise and Passive Microwave Remote Sensing from Space At L-Band
The spectral window at L-band (1.4 GHz) is important for passive remote sensing of soil moisture and ocean salinity from space, parameters that are needed to understand the hydrologic cycle and ocean circulation. At this frequency, radiation from extraterrestrial (mostly galactic) sources is strong and, unlike the constant cosmic background, this radiation is spatially variable. This paper presents a modern radiometric map of the celestial sky at L-band and a solution for the problem of determining what portion of the sky is seen by a radiometer in orbit. The data for the radiometric map is derived from recent radio astronomy surveys and is presented as equivalent brightness temperature suitable for remote sensing applications. Examples using orbits and antennas representative of those contemplated for remote sensing of soil moisture and sea surface salinity from space are presented to illustrate the signal levels to be expected. Near the galactic plane, the contribution can exceed several Kelvin.
LeVine, David M.↗
Mechanically Tunable Radiative Cooling for Adaptive Thermal Control
Passive radiative cooling is currently thefrontier technology in renewable-energy research. Interms of extraterrestrial applications, radiative cooling is a critical component to the thermalmanagement system of a spacecraft, where the extreme environment of space can cause largetemperature variations that can break and damage equipment. For terrestrial applications,nocturnal or daytime radiative cooling is expected to lead to cost-effective passive heatmanagement without the need of inefficient and costly artificial refrigeration technologies.However, most currently available radiative cooling systems cannot be changed dynamically andradiate a constant static amount of thermal power. Dynamically tunable adaptive radiativecooling systems will be a critical development to prolong the lifetime of spacecraft or improvethe efficiency of terrestrial cooling systems. Here we propose stretchable radiative coolingdesigns that can be substantially tuned by using the simple physical mechanism of mechanical strain. When their structure is stretched, the radiated power is significantly reduced. We developa modeling method that can simulate mechanical stretching combined with electromagnetic response to compute the tunable thermal emission of these new adaptive radiative coolingsystems. The presented photonically engineered structures can be used as coatings to achieveefficient adaptive thermal control of various objects in a cost-effective and environmentallyfriendly way. The proposed designs are much simpler to be realized than others found in theliterature and the best design achieves a high thermal emission power with a tunable range on theorder of 132 W/m2.
Andrew Butler↗
Criticality of Low-Energy Protons in Single-Event Effects Testing of Highly-Scaled Technologies
No abstract available
ionizing radiation↗
Deep space environments for human exploration
Mission scenarios outside the Earth's protective magnetic shield are being studied. Included are high usage assets in the near-Earth environment for casual trips, for research, and for commercial/operational platforms, in which career exposures will be multi-mission determined over the astronaut's lifetime. The operational platforms will serve as launching points for deep space exploration missions, characterized by a single long-duration mission during the astronaut's career. The exploration beyond these operational platforms will include missions to planets, asteroids, and planetary satellites. The interplanetary environment is evaluated using convective diffusion theory. Local environments for each celestial body are modeled by using results from the most recent targeted spacecraft, and integrated into the design environments. Design scenarios are then evaluated for these missions. The underlying assumptions in arriving at the model environments and their impact on mission exposures within various shield materials will be discussed. Published by Elsevier Ltd on behalf of COSPAR.
NASA Center LaRC↗
Survey of Experimental Results From One Year of PASP PLUS Orbital Operation
With PASP Plus as its primary payload, the APEX satellite was launched by a standard Pegasus rocket released from a NASA B-52 aircraft on 3 August 1994. A 70 deg inclination, 363 km X 2550 km orbit was achieved, allowing both investigation of space plasma effects on high-voltage operation in the perigee region and investigation of space radiation effects on array power output from passage through the inner radiation belt in the apogee region. Data gathering by PASP Plus was begun on 7 Aug 94 and ended on 11 Aug 95. In one year, PASP Plus collected an order of magnitude more data on environmental interactions on solar arrays than all previous space-borne photovoltaic experiments combined. The test arrays flown and the interactions-measuring and space-environment sensors of PASP Plus are described. The results of measurements of leakage current under test-array positive biasing and arc rates under negative biasing as a function of bias voltage, plasma density, array orientation, and other conditions are presented. The results of measurements of test-array power-output degradation caused by space radiation are also examined.
PHOTOVOLTAIC EFFECT↗
Galactic Noise and Passive Microwave Remote Sensing from Space at L-Band
The spectral window at L-band (1.4 GHz) is important for passive remote sensing of parameters such as soil moisture and ocean salinity best measured at long wavelengths. At L-band, radiation from extraterrestrial (galactic) sources is strong enough to warrant inclusion in calibration and retrieval algorithms and unlike the constant cosmic background is spatially variable. Previous estimates of the magnitude and distribution of this background radiation have been rather coarse, However, recent surveys of the radio sky at 1.4 GHz have made it possible to produce maps with sufficient spatial and radiometric accuracy to be relevant to remote sensing applications. This is of particular concern for remote sensing of sea surface salinity because the surface (water) is a good reflector and the salinity signal is relatively small. This paper presents a modem map of the radiometric sky at L-band and a solution to the problem of determining the portion of the sky seen by a radiometer in orbit. The data is derived from recent radio astronomy surveys and is presented as equivalent brightness temperature suitable for remote sensing applications. Examples using orbits and antennas representative of those contemplated for remote sensing of soil moisture and sea surface salinity from space are presented to illustrate the signal levels to be expected. Radiation near the galactic plane can exceed several kelvin.
LeVine, D. M.↗
Effects of Thermal Cycling on Control and Irradiated EPC 2nd Generation GaN FETs
The power systems for use in NASA space missions must work reliably under harsh conditions including radiation, thermal cycling, and exposure to extreme temperatures. Gallium nitride semiconductors show great promise, but information pertaining to their performance is scarce. Gallium nitride N-channel enhancement-mode field effect transistors made by EPC Corporation in a 2nd generation of manufacturing were exposed to radiation followed by long-term thermal cycling in order to address their reliability for use in space missions. Results of the experimental work are presented and discussed.
field effect transistor↗
Multidirectional Cosmic Ray Ion Detector for Deep Space CubeSats
Understanding the nature of anisotropy of solar energetic protons (SEPs) and galactic cosmic ray (GCR) fluxes in the interplanetary medium is crucial in characterizing time-dependent radiation exposure in interplanetary space for future exploration missions. NASA Glenn Research Center has proposed a CubeSat-based instrument to study solar and cosmic ray ions in lunar orbit or deep space. The objective of Solar Proton Anisotropy and Galactic cosmic ray High Energy Transport Instrument (SPAGHETI) is to provide multi-directional ion data to further understand anisotropies in SEP and GCR flux. The instrument is to be developed using large area detectors fabricated from high density, high purity silicon carbide (SiC) to measure linear energy transfer (LET) of ions. Stacks of these LET detectors are arranged in a CubeSat at orthogonal directions to provide multidirectional measurements. The low-noise, thermally-stable nature of silicon carbide and its radiation tolerance allows the multidirectional array of detector stacks to be packed in a 6U CubeSat without active cooling. A concept involving additional coincidence/anticoincidence detectors and a high energy Cherenkov detector is possible to further expand ion energy range and sensitivity.
Extraterrestrial Radiation↗
Thermal Cycling and High Temperature Reverse Bias Testing of Control and Irradiated Gallium Nitride Power Transistors
The power systems for use in NASA space missions must work reliably under harsh conditions including radiation, thermal cycling, and exposure to extreme temperatures. Gallium nitride semiconductors show great promise, but information pertaining to their performance is scarce. Gallium nitride N-channel enhancement-mode field effect transistors made by EPC Corporation in a 2nd generation of manufacturing were exposed to radiation followed by long-term thermal cycling and testing under high temperature reverse bias conditions in order to address their reliability for use in space missions. Result of the experimental work are presented and discussed.
thermal cycling tests↗
HIGH-ENERGY GAMMA-RAY ASTRONOMY
Brief review of the present status of high-energy gamma-ray astronomy and a report of results from the orbiting solar observatory
EXTRATERRESTRIAL RADIATION↗
Research results from the Radio Astronomy Explorer.
Extraterrestrial sources radiation including galactic, solar and magnetospheric radio emissions observed by RAE-I satellite at long wavelengths
Stone, R. G.↗
NASA to launch European cosmic ray experimental satellite
Europe's first observatory satellite (COS-B) designed for extraterrestrial gamma radiation study and launched on a Delta rocket for the European Space Agency (ESA) by NASA is briefly described. The COS-B's mission objectives are given along with launch operations.
Source record↗
Sea-surface temperature and salinity mapping from remote microwave radiometric measurements of brightness temperature
A technique to measure remotely sea surface temperature and salinity was demonstrated with a dual frequency microwave radiometer system. Accuracies in temperature of 1 C and in salinity of part thousand for salinity greater than 5 parts per thousand were attained after correcting for the influence of extraterrestrial background radiation, atmospheric radiation and attenuation, sea-surface roughness, and antenna beamwidth. The radiometers, operating at 1.43 and 2.65 GHz, comprise a third-generation system using null balancing and feedback noise injection. Flight measurements from an aircraft at an altitude of 1.4 km over the lower Chesapeake Bay and coastal areas of the Atlantic Ocean resulted in contour maps of sea-surface temperature and salinity with a spatial resolution of 0.5 km.
Hans-Juergen, C. B.↗
Development of a moon-based magnetospheric and coronal imager using a large broadband array
The 'Missions to and from Planet Earth' mandated by President Bush in 1989 provide a unique opportunity for magnetospheric and coronal plasma physicists to cooperate with low frequency radio astronomers in the development of an advanced experiment designed for the lunar surface. A large active lunar based array would sound the Earth's magnetosphere at VLF frequencies and the solar corona at decametric wavelengths allowing plasma physicists to map both the Earth's magnetosphere and those regions in the solar corona that trigger precursors to solar flares. With the transmitter silent, the array would become the ideal low frequency radio telescope, examining both geospace emissions such as auroral kilometric radiation and extraterrestrial signals from the planets, pulsars, supernova remnants, and active galactic nuclei. Both experiments satisfy requirements mandated in both 'Mission to Planet Earth' and in 'Mission from Planet Earth.' By proposing a cooperative effort both communities (plasma physicists and radio astronomers) stand to benefit. Jim Green, Director of the NASA Space Science Data Center (NSSDC) at GSFC; Tony Phillips, Research Fellow at California Institute of Technology; T. D. Carr, Director of the University of Florida Radio Observatory (UFRO) and the author are enlisting the cooperation of the scientific community in defining the system specifications. Some components, such as the receivers, will be standard 'off-the-shelf' items, and hence will require little developmental research. However, the individual antenna elements and the phasing and matching networks will require some R&D to satisfy the frequency requirements (20 KHz-40 MHz). By flying the experiment in Earth orbit first, Dr. Green proposes to gather valuable magnetospheric data as well as to prove the principle of the large moon based experiment. He claims that funding for the preliminary ground based studies at the UFRO may be available as early as FY-92.
Lebo, George↗