Space Life Support Systems

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Space Life Support Systems International
Space Station and Extravehicular Mobility Unit
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Overview

• External Structure of EMU and ISS
• The Primary Life Support System (PLSS) for the
  EMU
• The Environmental Control and Life Support System
  (ECLSS) onboard ISS
• Atmospheric Revitalization (EMU/ISS)
• Atmospheric Composition and Pressure
• CO2 Removal
• Temperature Control (EMU/ISS)

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EMU Parts
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External Structure of EMU

• From Inside to Outside 11 layers
• Liquid Cooling and Ventilation Garment (LCVG) 2
  layers, including liner
• Bladder (Polyurethane-coated Nylon)
• Polyester/Dacron Bladder Restraint

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External Structure of EMU

• Thermal Micrometeoroid Garment (TMG) 7 layers
• TMG Liner (Neoprene-coated Ripstop)
• 5 Layers of Aluminized Mylar
• Northal (Kevlar, Teflon, Nomex)

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External Structure of ISS

• Insulated by Multi-Layer Insulation (MLI), made
  of Mylar and Dacron.
• Mylar is a very effective insulator
• Kapton is used to protect the thin layers of
  Mylar
• Dacron separates the layers of Mylar to prevent
  conduction

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External Structure of ISS

• Micrometeoroid/Orbital Debris (MOD) Shielding is
  provided by several layers of ceramics, Kevlar,
  and other advanced materials.

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External Structure of ISS

• Air Pressure is further ensured by a series of
  restraint bladders.
• Aluminum is the primary material used for the ISS
  hull.

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Extravehicular Mobility Unit (EMU)

• Primary Life Support System (PLSS)

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The EMU Atmosphere

• 100 O2
• 4.3 psi
• CO2 and trace contaminant removal through LiOH or
  Metox
• Secondary Oxygen Supply can last up to 30 minutes

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Atmospheric Control in the EMU
http//paperairplane.mit.edu/16.423J/Space/SBE/pro
jects/LSSWEBSITE/Pages
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CO2 Removal in the EMU

• LiOH removes CO2 through a two-stage process
• H2O in the incoming air reacts with LiOH to
  produce LiOH- H2O solid
• LiOH- H2O solid reacts with CO2 to produce
  Lithium Carbonate and Water vapor
• Metox reacts similarly with CO2
• Silver Oxide reacts with CO2 and water to produce
  silver carbonate
• Metox is the preferable method, because it is
  regenerable.

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ISS Atmospheric Composition

• Composition 21.5 O2, 78.5 N2
• Pressure 14.7psi
• Current Air Source Cryogenic tanks
• Future Air Source Cryogenic Nitrogen tanks,
  Oxygen generated from water electrolysis.
• H2 will initially be dumped into space but may
  eventually be combined with CO2 to produce water
  and methane

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Carbon Dioxide Removal on ISS

• The Carbon Dioxide Removal Assembly (CDRA)
  employs a Zeolite Molecular Sieve to cleanse the
  cabin air.
• Molecular sieves utilize the uniform crystalline
  structure with inherent pores and cavities for
  adsorption.
• Currently, carbon dioxide is expelled into space.

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Temperature Regulation in the EMU
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EMU Water Circuits
http//paperairplane.mit.edu/16.423J/Space/SBE/pro
jects/LSSWEBSITE/Pages
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Temperature Control on ISS

• An air-to-water heat exchanger removes heat from
  the cabin atmosphere.
• As the air is cooled, the water vapor condenses
  and is incorporated into the water supply.
• Heat from onboard equipment is removed by cold
  water through cold plates.

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Temperature Control on ISS

• Internal heat is dumped from ISS through
  radiators located on the solar panels

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What are some other factors to consider?
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The End