The International Space Station (ISS) Environmental Control and Life Support System (ECLSS) is a life support system that provides or controls atmospheric pressure, fire detection and suppression, oxygen levels, waste management and water supply.
The International Space Station atmosphere is the main focus of the Environmental Control and Life Support Systems, but the ECLSS also collects, processes, and stores both waste and water produced and used by the crew—a process that recycles fluid from the sink, shower, toilet, and condensation from the air.
The ECLSS also serves as a cost-savings measure. The creation of the ECLSS allows for the accommodation of more crew on the Space Station, extends the time crew can stay in space, and significantly reduces the cost of operating the Space Station.
One of the more ingenious aspects of the ECLSS is the water recovery system, which provides clean water by reclaiming wastewater (including water from crew members’ urine), cabin humidity condensate, and water from the hydration system inside crew members’ Extra Vehicular Activity suits.
The recovered water must meet stringent purity standards before it can be used to support crew, extravehicular and payload activities. Water produced by the urine processor is combined with all other wastewaters and delivered to the water processor for treatment. The water processor sends the water through a series of multifiltration beds and a catalytic oxidizer for purification.
Waste disposal has been a particularly contested subsystem of the ECLSS. Currently, the ISS uses an open-loop waste disposal system where waste products are disposed of instead of reused.
But while this subsystem works in the ISS and shorter moon missions, it will likely need an overhaul for more substantial missions like to Mars and beyond.
According to NASA, deep space missions in the future will not be able to waste any resources. It will not be possible to resupply air and water due to the distances involved, nor will there be room to take it along on a spacecraft due to the volume and mass of consumables required for a voyage of months or years. Consequently, some kind of closed-loop waste disposal ECLSS will need to be in operation where waste products are recycled to provide resources that can be reused.
Want to learn more? Tonex offers Fundamentals of Environmental Control and Life Support System (ECLSS), a 2-day course where participants learn the fundamental principles and challenges of maintaining a habitable environment in space.
Participants also analyze and design ECLSS systems for different space missions and habitats as well as evaluate the performance and efficiency of various subsystems within an ECLSS.
For more information, questions, comments, contact us.