Comparison Of Martian Meteorites And Martian Regolith As Shield Materials For Galactic Cosmic Rays PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Comparison Of Martian Meteorites And Martian Regolith As Shield Materials For Galactic Cosmic Rays PDF full book. Access full book title Comparison Of Martian Meteorites And Martian Regolith As Shield Materials For Galactic Cosmic Rays.
Author | : Myung-Hee Y. Kim |
Publisher | : |
Total Pages | : 18 |
Release | : 1998 |
Genre | : Galactic cosmic rays |
ISBN | : |
Download Comparison of Martian Meteorites and Martian Regolith as Shield Materials for Galactic Cosmic Rays Book in PDF, ePub and Kindle
Author | : National Aeronautics and Space Administration (NASA) |
Publisher | : Createspace Independent Publishing Platform |
Total Pages | : 30 |
Release | : 2018-08-16 |
Genre | : |
ISBN | : 9781725577077 |
Download Comparison of Martian Meteorites and Martian Regolith As Shield Materials for Galactic Cosmic Rays Book in PDF, ePub and Kindle
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...
Author | : Myung-Hee Kim |
Publisher | : |
Total Pages | : 16 |
Release | : 1998 |
Genre | : |
ISBN | : |
Download Comparion of Martian Meteorites and Martian Regolith as Shield Materials for Galactic Cosmic Rays Book in PDF, ePub and Kindle
Author | : Jack Miller |
Publisher | : |
Total Pages | : 6 |
Release | : 2003 |
Genre | : Epoxy compounds |
ISBN | : |
Download Radiation Transport Properties of Potential in Situ-developed Regolith-epoxy Materials for Martian Habitats Book in PDF, ePub and Kindle
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.
Author | : Lisa C. Simonsen |
Publisher | : |
Total Pages | : 32 |
Release | : 1991 |
Genre | : Cosmic rays |
ISBN | : |
Download Radiation Protection for Human Missions to the Moon and Mars Book in PDF, ePub and Kindle
Author | : John E. Nealy |
Publisher | : |
Total Pages | : 28 |
Release | : 1988 |
Genre | : |
ISBN | : |
Download Solar-flare Shielding with Regolith at a Lunar-base Site Book in PDF, ePub and Kindle
Author | : M. Alexander |
Publisher | : |
Total Pages | : 122 |
Release | : 2001 |
Genre | : Mars (Planet) |
ISBN | : |
Download Mars Transportation Environment Definition Document Book in PDF, ePub and Kindle
Author | : Jared Allen Ruekberg |
Publisher | : |
Total Pages | : 148 |
Release | : 2015 |
Genre | : Meteoroids |
ISBN | : |
Download Structural Micrometeoroid and Radiation Shielding for Interplanetary Spacecraft Book in PDF, ePub and Kindle
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.
Author | : Barbara Cavalazzi |
Publisher | : Springer |
Total Pages | : 347 |
Release | : 2018-10-01 |
Genre | : Science |
ISBN | : 3319961756 |
Download Biosignatures for Astrobiology Book in PDF, ePub and Kindle
This book aims at providing a brief but broad overview of biosignatures. The topics addressed range from prebiotic signatures in extraterrestrial materials to the signatures characterising extant life as well as fossilised life, biosignatures related to space, and space flight instrumentation to detect biosignatures either in situ or from orbit. The book ends with philosophical reflections on the implications of life elsewhere. In the 15 chapters written by an interdisciplinary team of experts, it provides both detailed explanations on the nature of biosignatures as well as useful case studies showing how they are used and identified in ancient rocks, for example. One case study addresses the controversial finding of traces of fossil life in a meteorite from Mars. The book will be of interest not only to astrobiologists but also to terrestrial paleontologists as well as any reader interested in the prospects of finding a second example of life on another planet.
Author | : Grant Heiken |
Publisher | : CUP Archive |
Total Pages | : 796 |
Release | : 1991-04-26 |
Genre | : Science |
ISBN | : 9780521334440 |
Download Lunar Sourcebook Book in PDF, ePub and Kindle
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.