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Technical Paper

Cooling and Thermal Control Strategies in the Space Suit for Routine and Emergency Situations

2008-06-29
2008-01-1993
A series of demonstration studies were conducted with the aim of better understanding how to regulate body heat and thus enhance thermal comfort of astronauts during EVA requiring intensive physical exertion. The first study evaluated body zone heat transfer under different cooling temperatures in a liquid cooling garment (LCG), confirming the effectiveness of areas with high density tissue. The second study evaluated different configurations of hoods and neck scarves to maximize heat extraction from these key areas for heat release. The third study explored the possibility of regulating body heat by control of the water temperature circulating through selected body zones in the LCG, or blocking heat dissipation from particular body areas. The potential of heat insertion/removal from the head, hands, and feet to stabilize body comfort was evaluated in terms of the ability to advance this heat current “highway” from the core.
Technical Paper

Anthropometric and Blood Flow Characteristics Leading to EVA Hand Injury

2009-07-12
2009-01-2471
The aim of this study was to explore if fingernail delamination injury following EMU glove use may be caused by compression-induced blood flow occlusion in the finger. During compression tests, finger blood flow decreased more than 60%, however this occurred more rapidly for finger pad compression (4 N) than for fingertips (10 N). A pressure bulb compression test resulted in 50% and 45% decreased blood flow at 100 mmHg and 200 mmHg, respectively. These results indicate that the finger pad pressure required to articulate stiff gloves is more likely to contribute to injury than the fingertip pressure associated with tight fitting gloves.
Technical Paper

Comparison of Equivalent System Mass (ESM) of Yeast and Flat Bread Systems

2003-07-07
2003-01-2618
The Equivalent System Mass (ESM) metric developed by NASA describes and compares individual system impact on a closed system in terms of a single parameter, mass. The food system of a Mars mission may encompass a large percentage of total mission ESM, and decreasing this ESM would be beneficial. Yeast breads were made using three methods (hand & oven, bread machine, mixer with dough hook attachment & oven). Flat breads were made using four methods (hand & oven, hand & griddle, mixer with dough hook attachment & oven, mixer with dough hook attachment & griddle). Two formulations were used for each bread system (scratch ingredients, commercial mix). ESM was calculated for each of these scenarios. The objective of this study was to compare the ESM of yeast and flat bread production for a Martian surface outpost. Method (equipment) for both types of bread production was demonstrated to be the most significant influence of ESM when one equipment use was assumed.
Technical Paper

Informativeness of the Finger Temperature/Heat Flux as an Index of Human Thermal Status Under Local Cold Influences

2006-07-17
2006-01-2237
Introduction Human thermoregulation during EVA remains a challenge. The establishment of a high correlation between the thermal status of the fingers and the heat surplus/deficit in the body provides an index with potential to more effectively monitor and control the astronaut’s thermal status. This series of studies evaluated the changes in finger temperature (Tfing) trajectories in conditions relevant to EVA. Methods In different experiments, subjects were donned in a liquid cooling/warming garment (LCWG) that covered the full body surface except for the face and hands; they wore either a physiologically designed warming glove or the Phase VI glove. The experimental protocols were as follows: imposition of temperature differences in the left and right gloves; different thermal insulation levels of the gloves; sequential grasping of a highly cold rail in different glove conditions; placement of the finger thermistor on different sites of the finger.
Technical Paper

Pilot Investigation: Nominal Crew Induced Forces in Zero-G

1992-07-01
921155
Vibrational disturbance magnitude and frequency on space-flight missions is often a critical factor regarding mission success. Both materials processing experiments and astronomical investigations have specific microgravity environmental requirements. Recent efforts have been made to quantify the microgravity environment on the Space Shuttle Columbia by measuring gravity levels produced by specific mission events such as Orbiter engine burns, treadmill and ergometer activities, crew sleep periods, rotating chair operations, and body mass measurement operations. However, no measurements have been made of specific, nominal crewmember activities such as translating about the middeck, flight-deck, or in the Spacelab. This report presents pilot-study data of test subject forces induced by intravehicular activities such as push-offs and landings with both hands and feet. Five subjects participated in this investigation.
Technical Paper

Effect of Local Hand Thermal Insulation on Total and Local Comfort Under Different Levels of Body Heat Deficit

2005-07-11
2005-01-2977
Introduction: There are contradictory opinions regarding the contribution of local hand thermal insulation to support local and total comfort during extravehicular activity (EVA). Instead of a local correction by means of thermal insulation on the periphery of the body to prevent heat dissipation, it may be optimal to prevent heat dissipation from the body core. To examine such a concept, the effects of different insulation levels on the left and right hands on the heat flux and temperature mosaic on the hands was measured. These variables were assessed in relation to the level of heat deficit forming in the core organs and tissues. Methods: Six subjects (4 males, 2 females) were donned in a liquid cooling/warming garment (LCWG) that totally covered the body surface except for the face. Participants wore the Phase VI space gloves including the entire micrometeoroid garment (TMG) on the left hand, and the glove without the TMG on the right hand.
Technical Paper

ISS Phase 1 EVA Experience

2000-07-10
2000-01-2438
This paper summarizes specific and general lessons learned regarding extravehicular activity (EVA) during the joint U.S. and Russian Shuttle-Mir Program. Source data are drawn from the first hand experiences and publications accessible to the author who served as the U.S. co-chair of the Phase 1 Joint EVA Working Group. The information presented is pertinent to ongoing International Space Station (ISS) efforts and advanced exploration programs. Overall, this paper strives to show that EVA is just one component of an integrated manned space system and that its safety and success in this era of complex global ventures are reliant upon knowledge and experience balanced with new ideas.
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