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Subscale Testbed for Characterizing Regenerable Adsorbents used in Air Revitalization of Spacecraft Atmospheres

Dynamac Corporation-Oscar Monje
FAS Science Challenge/ Limerick Institute of Technology-Brid Brosnan
Published 2009-07-12 by SAE International in United States
A sub-scale testbed for characterizing the dynamic performance of regenerable adsorbents for filtering trace contaminants (TCs) from cabin atmospheres was built and tested. Regenerable adsorbents employed in pressure-swing adsorption (PSA) systems operate in a dynamic environment, where they undergo repeated loading / regeneration cycles. Adsorbents have a given chemical specificity for non-methane TCs depending on their composition, and on the humidity and temperature at which they operate. However, their ability to filter TCs is also affected by contact time, cycle time, regeneration vacuum quality and thermal conditioning. The test stand supplies gases of known composition and humidity to an adsorbent bed during the loading half-cycle, and allows automated sampling of inlet (pre-bed) and outlet (post-bed) gas concentrations by a gas chromatograph (GC) and a CO2 analyzer, The filter bed is designed for vacuum swing regeneration during short cycles (6 min) using high quality (<0.5 torr) vacuum. The test stand will be used to catalog the chemical specificity and dynamic performance of candidate adsorbents for future atmosphere revitalization (AR) technologies using environmental ranges (e.g. relative humidities,…
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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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Results of the Trace Contaminant Control Trade Study for Space Suit Life Support Development

Heather L. Paul, Mallory A. Jennings
Published 2009-07-12 by SAE International in United States
Designing the most effective and efficient life support systems is of extreme importance as the United States makes plans to return astronauts to the Moon. The Trace Contaminant Control System (TCCS), which will be located within the Portable Life Support System (PLSS) of the Constellation spacesuit element (CSSE), is responsible for removing contaminants that, at increased levels, can be hazardous to crew member health. These contaminants arise from several sources including metabolic production of the crew member (e.g., breathing, sweating, etc.) and offgassing of the spacesuit material layers. This paper summarizes the results of a trade study that investigated TCC technologies that were used in NASA space-suits and vehicles, as well as commercial and academic applications, to identify the best technology options for the CSSE PLSS. The trade study also looked at the feasibility of regeneration of TCC technologies, specifically to determine the viability of vacuum regeneration for on-back, real-time extravehicular activity.
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Comparative Configurations for Lunar Lander Habitation Volumes: 2005-2008

SAE International Journal of Aerospace

Northrop Grumman Corporation-Marc M. Cohen
  • Journal Article
  • 2009-01-2366
Published 2009-07-12 by SAE International in United States
This paper presents an overview of the progression of the contemplated candidate volumes for the Lunar Lander since the beginning of the Vision for Space Exploration in 2004. These sets of data encompass the 2005 Exploration Systems Architecture Study (ESAS), the 2006 Request for Information on the Constellation Lunar Lander, the 2007 Lander Design Analysis Cycle −1 (LDAC-1) and the 2008 Lunar Lander Development Study (LLDS). This data derives from Northrop Grumman Corporation analyses and design research. A key focus of this investigation is how well the lunar lander supports crew productivity.
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Engineering Support for Columbus: a Hydraulic Model of the Air Loop

Altran Italia SpA-Nicola di Francescantonio
Astrium-Roland Mueller
Published 2009-07-12 by SAE International in United States
On the 11th February 2008, the Columbus pressurized module has been successfully installed into the International Space Station. TAS-I (Thales Alenia Space - Italy) is responsible for the Off-Site Engineering Support to Columbus for ECLSS/TCS.A dedicated test-campaign has been proposed by TAS-I and performed on board Columbus during the first months after its docking to the Space Station, in order to have a Hydraulic Model of the entire Columbus air-loop correlated with real on-board data. A specific tool has been realized for the calculation of the Fans speeds (at ISFA, CFA1 or CFA2 level) to be expected and commanded in case of critical event so that a comfortable and safe environment for both astronauts and payloads can be ensured.The first part of this paper briefly presents the successful results of the employment of a tool previously realized by TAS-I for the calculation of cabin air volume flow rate from air loop telemetry data (primarily fans delta pressure and input current). The second part presents the description of the hydraulic model for the air-loop and its…
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Investigation of Transient Sublimator Performance

NASA Johnson Space Center-Rubik Sheth, Ryan A. Stephan
Paragon Space Development Corporation-Thomas O. Leimkuehler
Published 2009-07-12 by SAE International in United States
Sublimators have been used for heat rejection in a variety of space applications including the Apollo Lunar Module and the Extravehicular Mobility Unit (EMU). Sublimators typically operate with steady-state feedwater utilization at or near 100%. However, sublimators are currently being considered to operate in a cyclical topping mode during low lunar orbit for Altair and possibly Orion, which represents a new mode of operation. This paper will investigate the feedwater utilization when a sublimator is used in this nontraditional manner. This paper includes testing efforts to date to investigate the Orbit-Averaged Feedwater Utilization (OAFU) for a sublimator.
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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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Proposed Standards and Tools for Risk Analysis and Allocation of Robotic Systems to Enhance Crew Safety during Planetary Surface Exploration

SAE International Journal of Aerospace

McMaster University-Romain Chasseigne, Michael Demel, Dexter Jagula, Matthew Turnock
Orbital Sciences Corp-David Bodkin
  • Journal Article
  • 2009-01-2530
Published 2009-07-12 by SAE International in United States
Several space agencies have announced plans to return humans to the Moon in the near future. The objectives of these missions include using the Moon as a stepping-stone towards crewed missions to Mars, to test advanced technology, and to further exploration of the Moon for scientific research and in-situ resource utilization. To meet these objectives, it will be necessary to establish and operate a lunar base. As a result, a wide variety of tasks that may pose a number of crew health and safety risks will need to be performed on the surface of the Moon. Therefore, to ensure sustainable human presence on the Moon and beyond, it is essential to anticipate potential risks, assess the impact of each risk, and devise mitigation strategies. To address this, a nine-week intensive investigation was performed by an international, interdisciplinary and intercultural team on how to maximize crew safety on the lunar surface through a symbiotic relationship between astronauts and robots.To identify if and how robotic systems may be employed to enhance safety, it was necessary to establish…
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