Earth is the ultimate life support system. A multiplicity of biogeochemical cycles operate to maintain 'the balance of nature'. Oxygen is produced and carbon dioxide is fixed as biomass by autotrophic photosynthesizers energized by solar radiation. Heterotrophic organisms metabolize oxygen and plant biomass to produce carbon dioxide. Temperature is regulated by the complex interplay of solar radiation, radioactive decay within the Earth's interior, and a host of oceanic and atmospheric factors that are not well understood. Pure water is provided by natural weather cycles. Natural products are recycled by the ecosystem as one organism's waste is another organism's food.


When man ventures beneath the sea or into space he must take his environment with him. For short duration missions it is practical to take an ample supply of food, oxygen, and the gases from which water and electricity are generated. Excessive carbon dioxide levels can be scrubbed from the cabin atmosphere using expendible sorbent beds. Wastes can be stored for post-flight disposal. For longer duration missions the logistics requirements for resupply of life sustaining materials become a severe limitation. In these cases the deployment of more sophisticated systems for the purification and replenishment of air and water, the production of food, and the treatment of onboard wastes is required. Regenerative Life Support is the discipline dealing with the development of the physico-chemical and bioregenerative systems which are required to accomplish this task.


This is an overview of current Environmental Control and Life Support System (ECLSS) technologies deployed aboard the Shuttle Orbiter, the Russian Mir Space Station, and those to be deployed aboard International Space Station Alpha (ISSA) in the near future. A guide to the evolving Advanced Life Support Systems (ALSS) which will be required for future long duration missions to the Moon and Mars is also provided.

Current Environmental Control and Life Support System (ECLSS) Processes

Integrated Environmental Control and Life Support System (ECLSS) Systems

Advanced Life Support Systems (ALSS) Systems and Processes


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Author: Tugrul Sezen
[email protected]



Curator: Al Globus
If you find any errors on this page contact Al Globus.
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