Download or read book Comparison of Martian Meteorites and Martian Regolith as Shield Materials for Galactic Cosmic Rays written by Myung-Hee Y. Kim and published by . This book was released on 1998 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparison of Martian Meteorites and Martian Regolith As Shield Materials for Galactic Cosmic Rays written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-16 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical calculations of radiation attenuation due to energetic galactic cosmic rays behind Martian rock and Martian regolith material have been made to compare their utilization as shields for advanced manned missions to Mars because the detailed chemical signature of Mars is distinctly different from Earth. The modified radiation fields behind the Martian rocks and the soil model were generated by solving the Boltzmann equation using a HZETRN system with the 1977 Solar Minimum environmental model. For the comparison of the attenuation characteristics, dose and dose equivalent are calculated for the five different subgroups of Martian rocks and the Martian regolith. The results indicate that changes in composition of subgroups of Martian rocks have negligible effects on the overall shielding properties because of the similarity of their constituents. The differences for dose and dose equivalent of these materials relative to those of Martian regolith are within 0.5 and 1 percent, respectively. Therefore, the analysis of Martian habitat construction options using in situ materials according to the Martian regolith model composition is reasonably accurate. Adding an epoxy to Martian regolith, which changes the major constituents of the material, enhances shielding properties because of the added hydrogenous constituents. Kim, Myung-Hee Y. and Thibeault, Sheila A. and Simonsen, Lisa C. and Wilson, John W. Langley Research Center NASA/TP-1998-208724, NAS 1.60:208724, L-17722 RTOP 199-45-16-12...
Download or read book Comparion of Martian Meteorites and Martian Regolith as Shield Materials for Galactic Cosmic Rays written by Myung-Hee Kim and published by . This book was released on 1998 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiation Transport Properties of Potential in Situ developed Regolith epoxy Materials for Martian Habitats written by Jack Miller and published by . This book was released on 2003 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mission crews in space outside the Earth's magnetic field will be exposed to high energy heavy charged particles in the galactic cosmic radiation (GCR). These highly ionizing particles will be a source of radiation risk to crews on extended missions to the Moon and Mars, and the biological effects of and countermeasures to the GCR have to be investigated as part of the planning of exploration-class missions. While it is impractical to shield spacecraft and planetary habitats against the entire GCR spectrum, biological and physical studies indicate that relatively modest amounts of shielding are effective at reducing the radiation dose. However, nuclear fragmentation in the shielding materials produces highly penetrating secondary particles, which complicates the problem in some cases, some shielding is worse than none at all. Therefore the radiation transport properties of potential shielding materials need to be carefully investigated. One intriguing option for a Mars mission is the use of material from the Martian surface, in combination with chemicals carried from Earth and or fabricated from elements found in the Martian atmosphere, to construct crew habitats. We have measured the transmission properties of epoxy-Martian regolith composites with respect to heavy charged particles characteristic of the GCR ions which bombard the Martian surface. The composites were prepared at NASA Langley Research Center using simulated Martian regolith, in the process also evaluating fabrication methods which could lead to technologies for in situ fabrication on Mars. Initial evaluation of the radiation shielding properties is made using radiation transport models developed at NASA-LaRC, and the results of these calculations are used to select the composites with the most favorable radiation transmission properties. These candidates are then evaluated at particle accelerators which produce beams of heavy charged particles representative in energy and charge of the radiation at the surface of Mars. The ultimate objective is to develop the models into a design tool for use by mission planners, flight surgeons and radiation health specialists.
Download or read book Radiation Protection for Human Missions to the Moon and Mars written by Lisa C. Simonsen and published by . This book was released on 1991 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mars Transportation Environment Definition Document written by M. Alexander and published by . This book was released on 2001 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solar flare Shielding with Regolith at a Lunar base Site written by John E. Nealy and published by . This book was released on 1988 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Micrometeoroid and Radiation Shielding for Interplanetary Spacecraft written by Jared Allen Ruekberg and published by . This book was released on 2015 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper focused on two significant space forces that can affect the success of a spacecraft: the radiation and micrometeoroid environments. Both are looked at in the context of the region of space between Earth and Mars. The goal was create reference environments, to provide context to results of environmental modeling, and to provide recommendations to assist in early design decisions of interplanetary spacecraft. The radiation section of this report used NASA's OLTARIS program to generate data for analysis. The area of focus was on the radiation effects for crewed missions, therefore effective dose equivalent was the metric used to compare different models of radiation and shielding. Test spheres with one, two, or three different materials layers were compared, along with modifiers such as alloys or weight vs. thickness emphasis. Results were compared to limits set by the European and Russian Space Agencies to provide context. The results hinged heavily on the intensity of the Solar Particle Events (SPEs), with testing using additional temporary radiation shielding proving to be a requirement for feasible shielding masses. Differences in shield material effectiveness were found to be negligible for thin Galactic Cosmic Rays (GCRs) and thick SPEs. Thick shields were found to perform better when the more efficient shield was on the outside of the test sphere. The micrometeoroid section used equations and programs from multiple sources to generate state vectors, flux, and finally impact models for four different case studies. Impacts v were generated with mass, velocity, and impact angle/location statistics. The mass and velocity results were run through statistical software to generate information such as mean and standard deviation with confidence intervals. Also looked at were higher mass impacts, limited to above 10-3 grams as opposed to above 10-6 for the regular case. The results of this show that very thin monolithic shields (0.1 cm-0.25 cm) could protect against the average 10-6 impact. The Ram, Nadir, and Anti-sun faces received the highest quantity of impacts and Wake received the least. When looking at the worst cases average mass and velocity for the high mass impacts significantly higher shielding was required to prevent penetration (up to 5 cm for some cases). However, the test cases had probabilities of no high mass impacts greater than 46% of the time, with shorter mission having greater chances of no high mass impacts.
Download or read book NASA Langley Scientific and Technical Information Output 1998 written by and published by . This book was released on 1999 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 40th AIAA Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 2002 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Space Research written by and published by . This book was released on 2008 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Instruments Methods and Missions for Astrobiology written by and published by . This book was released on 1999 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Safe on Mars written by National Research Council and published by National Academies Press. This book was released on 2002-05-29 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study, commissioned by the National Aeronautics and Space Administration (NASA), examines the role of robotic exploration missions in assessing the risks to the first human missions to Mars. Only those hazards arising from exposure to environmental, chemical, and biological agents on the planet are assessed. To ensure that it was including all previously identified hazards in its study, the Committee on Precursor Measurements Necessary to Support Human Operations on the Surface of Mars referred to the most recent report from NASA's Mars Exploration Program/ Payload Analysis Group (MEPAG) (Greeley, 2001). The committee concluded that the requirements identified in the present NRC report are indeed the only ones essential for NASA to pursue in order to mitigate potential hazards to the first human missions to Mars.
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 2000 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lunar Sourcebook written by Grant Heiken and published by CUP Archive. This book was released on 1991-04-26 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt: The only work to date to collect data gathered during the American and Soviet missions in an accessible and complete reference of current scientific and technical information about the Moon.
Download or read book Evolving and Revolutionary Technologies for the New Millennium written by Leslie Jay Cohen and published by . This book was released on 1999 with total page 1310 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Views of the Moon written by Bradley L. Jolliff and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 60 of Reviews in Mineralogy and Geochemistry assesses the current state of knowledge of lunar geoscience, given the data sets provided by missions of the 1990's, and lists remaining key questions as well as new ones for future exploration to address. It documents how a planet or moon other than the world on which we live can be studied and understood in light of integrated suites of specific kinds of information. The Moon is the only body other than Earth for which we have material samples of known geologic context for study. This volume seeks to show how the different kinds of information gained about the Moon relate to each other and also to learn from this experience, thus allowing more efficient planning for the exploration of other worlds.
