Liquid Cooling and Ventilation Garment
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A Liquid Cooling and Ventilation Garment, or LCVG, is a form-fitting garment worn by astronauts in order to maintain a comfortable core body temperature during extra-vehicular activity. The LCVG accomplishes this task by circulating cool water through a network of flexible tubes in direct contact with the astronaut's skin. The water draws heat away from the body, resulting in a lower core temperature. The water then returns to the Primary Life Support System, or PLSS, where it radiates heat into space, thereby cooling before being recirculated.
Because the space environment is essentially a vacuum, heat cannot be lost through heat conduction, and can only be dissipated through thermal radiation, a much slower process. Thus, even though the environment of space can be extremely cold, excessive heat build-up is inevitable. Without an LCVG, there would be no means by which to expel this heat, and it would affect not only EVA performance, but the health of the suit occupant as well. The LCVG used with the Apollo/Skylab A7L suit could remove heat at a rate of approximately 2000 Btu/h (600 watts).[1]
The LCVG used with NASA's Extravehicular Mobility Unit is primarily constructed of spandex, with a nylon tricot liner.[2] The tubes are polyvinyl chloride.
A Liquid Cooling and Ventilation Garment is differentiated from a Liquid Cooling Garment by the presence of ventilation ducts, which draw exhaled gas from the suit's extremities and return it to the Primary Life Support System.
[edit] References
- ^ Carson, Maurice A.; Rouen, Michael N., Lutz, Charles C., and McBarron, James W. II. Biomedical Results of Apollo - Section VI - Chapter 6 - Extravehicular Mobility Unit. Lyndon B. Johnson Space Center.
- ^ Freudenrich, Craig C.. How Spacesuits Work. How Stuff Works. Retrieved on 2007-01-18.
[edit] External links
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