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Development and Testing of a Sorbent-Based Atmosphere Revitalization System 2008/2009

SAE International Journal of Aerospace

ECLS Technologies, LLC-Lee A. Miller
NASA Marshall Space Flight Center-James C. Knox
  • Journal Article
  • 2009-01-2445
Published 2009-07-12 by SAE International in United States
The design and evaluation of a Vacuum-Swing Adsorption (VSA) system to remove metabolic water and metabolic carbon dioxide from a spacecraft atmosphere is presented. The approach for Orion and Altair is a VSA system that removes not only 100 percent of the metabolic CO2 from the atmosphere, but also 100% of the metabolic water as well, a technology approach that has not been used in previous spacecraft life support systems. The design and development of an Orion Crew Exploration Vehicle Sorbent Based Atmosphere Revitalization system, including test articles, a facility test stand, and full-scale testing in late 2008 and early 2009 is discussed.
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Flammability of Human Hair in Exploration Atmospheres

SAE International Journal of Aerospace

Cornell University-Elizabeth A. Smith
NASA Glenn Research Center at Lewis Field-Sandra L. Olson, DeVon W. Griffin, David L. Urban, Gary A. Ruff
  • Journal Article
  • 2009-01-2512
Published 2009-07-12 by SAE International in United States
To investigate the flammability of human hair, a series of normal and microgravity flame spread tests over human hair were performed in a low-speed flow tunnel to simulate spacecraft ventilation flows (∼20 cm/s). The tunnel atmosphere pressure and oxygen concentration was varied over the range of anticipated exploration atmospheres (21–34% O2 in N2, 8–14.7 psia). While hair is marginally flammable in air, spreading upward but not downward, it burns extremely well at or above 30% O2 in any direction or g-level. The spread is characterized by a quick spread over the surface ‘nap’ or ‘frizz’, followed by continued bulk burning. Two hair ‘styles’ were tested — short hair and long hair — and style does not seem to affect initial nap spread significantly.Opposed and concurrent nap spread rates are similar in 0g under comparable conditions. Oxygen concentration has a strong effect on flame spread rates. Concurrent spread rates are more than an order of magnitude faster in 30% O2 compared to 21% O2. Gravity also affects flame spread, with 1g concurrent (upward) being the fastest…
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A Comparison between One- and Two-Loop ATCS Architectures Proposed for CEV

SAE International Journal of Aerospace

Jacobs Technology (ESCG)-Dustin A. Ochoa , Walt Vonau
NASA (Johnson Space Center)-Michael K. Ewert
  • Journal Article
  • 2009-01-2458
Published 2009-07-12 by SAE International in United States
In an effort to help future crewed spacecraft thermal control analysts understand the characteristics of one-and two-loop Active Thermal Control Systems (ATCS), a comparison was made between the one- and two-loop ATCS architectures officially proposed for the Crew Exploration Vehicle (CEV) in Design Analysis Cycle 1 (DAC1) and DAC2, respectively. This report provides a description of each design, along with mass and power estimates derived from their respective Master Equipment List (MEL) and Power Equipment List (PEL). Since some of the components were sized independent of loop architecture (ex. coldplates and heat exchangers), the mass and power for these components were based on the MEL and PEL of the most mature design (i.e. two-loop architecture). The mass and power of the two architectures are then compared and the ability of each design to meet CEV requirements is discussed.
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Effect of Illumination Angle on the Performance of Dusted Thermal Control Surfaces in a Simulated Lunar Environment

SAE International Journal of Aerospace

NASA Glenn Research Center-James R. Gaier
  • Journal Article
  • 2009-01-2420
Published 2009-07-12 by SAE International in United States
JSC-1A lunar simulant has been applied to AZ93 and AgFEP thermal control surfaces on aluminum substrates in a simulated lunar environment. The temperature of these surfaces was monitored as they were heated with a solar simulator using varying angles of incidence and cooled in a 30 K coldbox. Thermal modeling was used to determine the solar absorptivity (a) and infrared emissivity (e) of the thermal control surfaces in both their clean and dusted states. It was found that even a sub-monolayer of dust can significantly raise the α of either type of surface. A full monolayer can increase the α/ε ratio by a factor of 3–4 over a clean surface. Little angular dependence of the α of pristine thermal control surfaces for both AZ93 and AgFEP was observed, at least until 30° from the surface. The dusted surfaces showed the most angular dependence of α when the incidence angle was in the range of 25° to 35°. Samples with a full monolayer, like those with no dust, showed little angular dependence in α. The ε…
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Development of an In-line Urine Monitoring System for the International Space Station

SAE International Journal of Aerospace

National Aeronautics and Space Administration, Johnson Space Center-James Lee Broyan , Branelle R. Cibuzar
  • Journal Article
  • 2009-01-2400
Published 2009-07-12 by SAE International in United States
Exposure to microgravity during space flight causes bone loss when calcium and other metabolic by-products are excreted in urine voids. Frequent and accurate measurement of urine void volume and constituents is thus essential in determining crew bone loss and the effectiveness of the countermeasures that are taken to minimize this loss. Earlier space shuttle Urine Monitoring System (UMS) technology was unable to accurately measure urine void volumes due to the cross-contamination that took place between users, as well as to fluid system instabilities. Crew urine voids are currently collected manually in a flexible plastic bag that contains a known tracer quantity. A crew member must completely mix the contents of this bag before withdrawing a representative syringe sample for later ground analysis. The existing bag system accuracy is therefore highly dependent on mixing technique.
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Analyses of Several Space Radiation-Mitigating Materials: Computational and Experimental Results

SAE International Journal of Aerospace

William Atwell, Paul Boeder, Richard Wilkins, Brad Gersey, Kristina Rojdev
  • Journal Article
  • 2009-01-2338
Published 2009-07-12 by SAE International in United States
Long-term exposure to the space radiation environment poses deleterious effects to both humans and space systems. The major sources of the radiation effects come from high energy galactic cosmic radiation and solar proton events. In this paper we investigate the radiation-mitigation properties of several shielding materials for possible use in spacecraft design, surface habitats, surface rovers, spacesuits, and temporary shelters. A discussion of the space radiation environment is presented in detail. Parametric radiation shielding analyses are presented using the NASA HZETRN 2005 code and are compared with ground-based experimental test results using the Loma Linda University Proton Therapy facility.
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Philosophies Applied in the Selection of Spacesuit Joint Range-of-Motion Requirements

SAE International Journal of Aerospace

National Aeronautics and Space Administration Johnson Space Center-Lindsay Aitchison
  • Journal Article
  • 2009-01-2538
Published 2009-07-12 by SAE International in United States
Space suits are the most important tool for astronauts working in harsh space and planetary environments; suits keep crewmembers alive and allow them to perform exploration, construction, and scientific tasks on a routine basis over a period of several months. The efficiency with which the tasks are performed is largely dictated by the mobility features of the space suit. For previous space suit development programs, the mobility requirements were written as pure functional mobility requirements that did not separate joint ranges of motion from joint torques. The Constellation Space Suit Element has the goal to make more quantitative mobility requirements that focused on the individual components of ‘mobility’ to enable future suit designers to build and test systems more effectively. This paper details the test planning and selection process for the Constellation space suit pressure garment range of motion requirements.
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Thermal Design Trade Study for the Mars Science Laboratory ChemCam Body Unit

SAE International Journal of Aerospace

Applied Sciences Laboratory-Siu-Chun Lee
Jet Propulsion Laboratory, California Institute of Technology-Glenn T. Tsuyuki, Elisabeth L. Morse
  • Journal Article
  • 2009-01-2462
Published 2009-07-12 by SAE International in United States
The Mars Science Laboratory will be the next Martian mobility system that is scheduled to launch in the fall of 2011. The ChemCam Instrument is a part of the MSL science payload suite. It is innovative for planetary exploration in using a technique referred to as laser breakdown spectroscopy to determine the chemical composition of samples from distances of up to about 9 meters away. ChemCam is led by a team at the Los Alamos National Laboratory and the Centre d'Etude Spatiale des Rayonnements in Toulouse, France.The portion of ChemCam that is located inside the Rover, the ChemCam Body Unit contains the imaging charged-coupled device (CCD) detectors. Late in the design cycle, the ChemCam team explored alternate thermal design architectures to provide CCD operational overlap with the Rover's remote sensing instruments. This operational synergy is necessary to enable planning for subsequent laser firings and geological context. This paper will present the CCD thermal design trades that would increase the CCD operational window. Due to the minimum lead time to implement design modifications, the passive control…
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Status of Developing a Near Real-Time Capability for Estimating Space Radiation Exposure Using EMMREM

SAE International Journal of Aerospace

Boston University-Nathan A. Schwadron, Kamen Kozarev
The University of Tennessee-Richard B. Hatcher, Lawrence W. Townsend
  • Journal Article
  • 2009-01-2340
Published 2009-07-12 by SAE International in United States
The central objective of the Earth-Moon-Mars Radiation Environment Module (EMMREM) project is to develop and validate a numerical module for completely characterizing time-dependent radiation exposure in the Earth-Moon-Mars and Interplanetary space environments. An important step in the process of building this system is the development of the interfaces between EMMREM's internal components, many of which have existed previously as stand-alone simulation codes. This work specifically discusses the development and implementation of the interface, primarily using the Perl scripting language, between two input data set generators, one of which describes the space radiation environment at some desired location, and a space radiation transport and shielding code, BRYNTRN, that provides estimates at fairly short time intervals of dose and dose equivalent behind shielding.
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Unique Regeneration Steps for the Sorbent-Based Atmosphere Revitalization System Designed for CO2 and H2O Removal from Spacecraft Cabins

SAE International Journal of Aerospace

Marshall Space Flight Center, National Aeronautics and Space Administration-James C. Knox
University of South Carolina-Armin D. Ebner , James A. Ritter
  • Journal Article
  • 2009-01-2532
Published 2009-07-12 by SAE International in United States
An SBAR system for H2O and CO2 removal from spacecraft cabin air was studied both experimentally and theoretically. An emphasis was placed on its purgeless, deep vacuum regeneration step. Three evacuation steps were studied: 1) single ended depressurization (SED) through the feed end of the bed; 2) simultaneous dual ended depressurization (DED) through both ends of the bed; and 3) simultaneous triple ended depressurization (TED) through both ends of the bed and a port located at some axial position. TED resulted in a lower average bed pressure at the end of evacuation compared to DED, which, in turn caused more CO2 to be removed. An optimal third port location also existed. The use of TED should allow the SBAR bed size to be reduced.
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