[PDF] Structural Micrometeoroid And Radiation Shielding For Interplanetary Spacecraft eBook

Author : Jared Allen Ruekberg
Publisher :
Page : 148 pages
File Size : 28,66 MB
Release : 2015
Category : Meteoroids
ISBN :

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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 : John William Wilson
Publisher :
Page : 496 pages
File Size : 29,52 MB
Release : 1997
Category : Extraterrestrial radiation
ISBN :

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The purpose of the workshop was to define requirements for the development and evaluation of high performance shield materials and designs and to develop ideas regarding approaches to radiation shielding.

Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 28 pages
File Size : 17,55 MB
Release : 2018-06-16
Category :
ISBN : 9781721255382

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Polymeric materials on space vehicles and high-altitude aircraft win be exposed to highly penetrating radiations. These radiations come from solar flares and galactic cosmic rays (GCR). Radiation from solar flares consists primarily of protons with energies less than 1 GeV. On the other hand, GCR consist of nuclei with energies as high as 10(exp 10) GeV. Over 90% of the nuclei in GCR are protons and alpha particles, however there is a small but significant component of particles with atomic numbers greater than ten. Particles with high atomic number (Z) and high energy interact with very high specific ionization and thus represent a serious hazard for humans and electronic equipment on a spacecraft or on high-altitude commercial aircraft (most importantly for crew members who would have long exposures). Neutrons generated by reactions with the high energy particles also represent a hazard both for humans and electronic equipment. Kiefer, Richard L. and Orwoll, Robert A. Langley Research Center

Author : Gabriel D. Maestas
Publisher :
Page : 0 pages
File Size : 14,59 MB
Release : 2022
Category : Composite materials
ISBN :

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One of the difficulties associated with prior investigations of the FFCC as well as other investigations of nonhomogeneous materials is in modeling the heterogenous layers for analysis in the Space Environment Information System (SPENVIS). In a past investigation, the fluid-filled porous core was modeled as multiple stacked layers of its homogenous components, however this method is suboptimal since layer order affects results in SPENVIS. This is remedied in the current investigation by use of a homogenization process, as discussed in Section Chapter 3, allowing for a more accurate analysis of the FFCC.Here, the FFCC has been considered for Total Ionizing Dose (TID) after shielding in a silicon detector by computation with the Multi-Layered Shielding Simulation (MULASSIS) tool from GEANT4 in SPENVIS. This has been done in an effort to model the FFCC radiation shielding capabilities in two space environments, Medium Earth Orbit and Interplanetary Space. It has been found that a variety of the tested FFCC compositions have outperformed traditional shielding materials by a Quality Function Deployment (QFD) methodology of shielding, density, and cost. Dependent on specific composition, the FFCC either meets or exceeds the shielding capability of polyethylene, the NASA standard for shielding materials, while maintaining its broad range of multifunctionality [4]. It is this combination of improved shielding with multifunctionality that advances the FFCC as a potential Mars-class material for use as a spacecraft structural layer or within an off-world habitat.

Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 32 pages
File Size : 47,36 MB
Release : 2018-06-11
Category :
ISBN : 9781721018444

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This part of Exploration Atmospheres Working Group analyses focuses on the potential use of nonmetallic composites as the interior walls and structural elements exposed to the atmosphere of the spacecraft or habitat. The primary drive to consider nonmetallic, polymer-based composites as an alternative to aluminum structure is due to their superior radiation shielding properties. But as is shown in this analysis, these composites can also be made to combine superior mechanical properties with superior shielding properties. In addition, these composites can be made safe; i.e., with regard to flammability and toxicity, as well as "smart"; i.e., embedded with sensors for the continuous monitoring of material health and conditions. The analysis main conclusions are that (1) smart polymer-based composites are an enabling technology for safe and reliable exploration missions, and (2) an adaptive, synergetic systems approach is required to meet the missions requirements from structure, properties, and processes to crew health and protection for exploration missions.Barghouty, A. F. and Thibeault, S. A.Langley Research Center; Marshall Space Flight CenterRADIATION SHIELDING; EXTRATERRESTRIAL RADIATION; FLAMMABILITY; TOXICITY; SPACECREWS; AEROSPACE MEDICINE; HABITATS; PROTECTION

Author :
Publisher :
Page : 5 pages
File Size : 24,84 MB
Release : 2002
Category :
ISBN :

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Accelerator-based measurements and model calculations have been used to study the heavy ion radiation transport properties of materials in use on the International Space Station (ISS). Samples of the ISS aluminum outer hull were augmented with various configurations of internal wall material and polyethylene. The materials were bombarded with high energy Fe ions characteristic of a significant part of the Galactic Cosmic Ray (GCR) heavy ion spectrum. Transmitted primary ions and charged fragments produced in nuclear collisions in the materials were measured near the beam axis, and a model was used to extrapolate from the data to lower beam energies and to a lighter ion. For the materials and ions studied, at incident particle energies from 1037 MeV/nucleon down to at least 600 MeV/nucleon, nuclear fragmentation reduces the average dose and dose equivalent per incident ion. At energies below 400 MeV/nucleon, the calculation predicts that as material is added, increased ionization energy loss produces increases in some dosimetric quantities. These limited results suggest that the addition of modest amounts of polyethylene or similar material to the interior of the ISS will reduce the dose to ISS crews from space radiation; however the radiation transport properties of ISS materials should be evaluated with a realistic space radiation field.

Author : National Research Council
Publisher : National Academies Press
Page : 132 pages
File Size : 32,94 MB
Release : 2008-06-29
Category : Science
ISBN : 0309113830

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As part of the Vision for Space Exploration (VSE), NASA is planning for humans to revisit the Moon and someday go to Mars. An important consideration in this effort is protection against the exposure to space radiation. That radiation might result in severe long-term health consequences for astronauts on such missions if they are not adequately shielded. To help with these concerns, NASA asked the NRC to further the understanding of the risks of space radiation, to evaluate radiation shielding requirements, and recommend a strategic plan for developing appropriate mitigation capabilities. This book presents an assessment of current knowledge of the radiation environment; an examination of the effects of radiation on biological systems and mission equipment; an analysis of current plans for radiation protection; and a strategy for mitigating the risks to VSE astronauts.

Author : Erik Seedhouse
Publisher : Springer Science & Business Media
Page : 276 pages
File Size : 48,69 MB
Release : 2012-02-02
Category : Science
ISBN : 1441997482

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"Interplanetary Outpost" follows the mission architecture template of NASA's plan for Human Outer Planet Exploration (HOPE), which envisions sending a crew to the moon Callisto to conduct exploration and sample return activities. To realize such a mission, the spacecraft will be the most complex interplanetary vehicle ever built, representing the best technical efforts of several nations. A wealth of new technologies will need to be developed, including new propulsion systems, hibernation strategies, and revolutionary radiation shielding materials. Step by step, the book will describe how the mission architecture will evolve, how crews will be selected and trained, and what the mission will entail from launch to landing. However, the focus of "Interplanetary Outpost" is on the human element. The extended duration, logistical challenges, radiation concerns, communication lag times, isolation, and deleterious effects on the human body will conspire to not only significantly impair human performance but also affect the behavior of crewmembers. This book addresses each of these issues in detail while still providing the reader with a background to the necessary elements comprising such a mission.