Life-support system
The concept can also be extended to submarines, crewed submersibles and atmospheric diving suits, where the breathing gas requires treatment to remain respirable, and the occupants are isolated from the outside ambient pressure and temperature.
Other environmental considerations such as radiation, gravity, noise, vibration, and lighting also factor into human physiological response in outer space, though not with the more immediate effect that the metabolic parameters have.
Outer space life-support systems maintain atmospheres composed, at a minimum, of oxygen, water vapor and carbon dioxide.
This is done, for example, by composting toilets which reintegrate waste material (excrement) back into the system, allowing the nutrients to be taken up by the food crops.
Depending on the length of the mission, astronauts may need artificial gravity to reduce the effects of space adaptation syndrome, body fluid redistribution, and loss of bone and muscle mass.
American Mercury, Gemini and Apollo spacecraft contained 100% oxygen atmospheres, suitable for short duration missions, to minimize weight and complexity.
[5] For the Space Shuttle, NASA includes in the ECLSS category systems that provide both life support for the crew and environmental control for payloads.
[6] The life-support system on the Soyuz spacecraft is called the Kompleks Sredstv Obespecheniya Zhiznideyatelnosti (KSOZh) (Russian: Комплекс Средств Обеспечения Жизнедеятельности (KCOЖ)).
Underwater habitats and surface saturation accommodation facilities provide life-support for their occupants over periods of days to weeks.
Underwater habitats balance internal pressure with the ambient external pressure, allowing the occupants free access to the ambient environment within a specific depth range, while saturation divers accommodated in surface systems are transferred under pressure to the working depth in a closed diving bell The life support system for the bell provides and monitors the main supply of breathing gas, and the control station monitors the deployment and communications with the divers.
[12] The accommodation life support system maintains the chamber environment within the acceptable range for health and comfort of the occupants.
[13] Micro-Ecological Life Support System Alternative (MELiSSA) is a European Space Agency led initiative, conceived as a micro-organisms and higher plants based ecosystem intended as a tool to gain understanding of the behaviour of artificial ecosystems, and for the development of the technology for a future regenerative life-support system for long term crewed space missions.
CyBLiSS ("Cyanobacterium-Based Life Support Systems") is a concept developed by researchers from several space agencies (NASA, the German Aerospace Center and the Italian Space Agency) which would use cyanobacteria to process resources available on Mars directly into useful products, and into substrates[clarification needed] for other key organisms of Bioregenerative life support system (BLSS).
[14] The goal is to make future human-occupied outposts on Mars as independent of Earth as possible (explorers living "off the land"), to reduce mission costs and increase safety.
Even though developed independently, CyBLiSS would be complementary to other BLSS projects (such as MELiSSA) as it can connect them to materials found on Mars, thereby making them sustainable and expandable there.
