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For other uses of "Life support", see Life support (disambiguation).

In human spaceflight, a life support system is a group of devices that allow a human being to survive in space. US government space agency NASA,[1] and private spaceflight companies use the term environmental control and life support system or the acronym ECLSS when describing these systems for their human spaceflight missions.[2] The life support system may supply air, water and food. It must also maintain the correct body temperature, an acceptable pressure on the body and deal with the body's waste products. Shielding against harmful external influences such as radiation and micro-meteorites may also be necessary. Components of the life support system are life-critical, and are designed and constructed using safety engineering techniques.

Human physiological and metabolic needs[edit]

A crewmember of typical size requires approximately 5 kg or 11.0231 lb(total) of food, water, and oxygen per day to perform the standard activities on a space mission, and outputs a similar amount in the form of waste solids, waste liquids, and carbon dioxide.[3] The mass breakdown of these metabolic parameters is as follows: 0.84 kg of oxygen, 0.62 kg of food, and 3.52 kg of water consumed, converted through the body's physiological processes to 0.11 kg of solid wastes, 3.87 kg of liquid wastes, and 1.00 kg of carbon dioxide produced. These levels can vary due to activity level, specific to mission assignment, but will correlate to the principles of mass balance. Actual water use during space missions is typically double the specified values mainly due to non-biological use (i.e. personal cleanliness). Additionally, the volume and variety of waste products varies with mission duration to include hair, finger nails, skin flaking, and other biological wastes in missions exceeding one week in length. Other environmental considerations such as radiation, gravity, noise, vibration, and lighting also factor into human physiological response in space, though not with the more immediate effect that the metabolic parameters have.

Atmosphere[edit]

Space life support systems maintain atmospheres composed, at a minimum, of oxygen, water vapor and carbon dioxide. The partial pressure of each component gas adds to the overall barometric pressure.

By reducing or omitting diluents (constituents other than oxygen, e.g., nitrogen and argon) the total pressure can be lowered to a minimum of 21 kPa, the partial pressure of oxygen in the Earth's atmosphere at sea level. This can lighten spacecraft structures, reduce leaks and simplify the life support system.

However, the elimination of diluent gases substantially increases fire risks, especially in ground operations when for structural reasons the total cabin pressure must exceed the external atmospheric pressure; see Apollo 1. Furthermore, oxygen toxicity becomes a factor at high oxygen concentrations. For this reason, most modern crewed spacecraft use conventional air (nitrogen/oxygen) atmospheres and use pure oxygen only in pressure suits during extravehicular activity where acceptable suit flexibility mandates the lowest inflation pressure possible.

Water[edit]

Water is consumed by crew members through drinking, cleaning activities, EVA thermal control, and emergency uses. It must be stored, used, and reclaimed (from waste water) efficiently since no on-site sources currently exist for the environments reached in the course of human space exploration.

Food[edit]

Life support systems could include a plant cultivation system which allows food to be grown within buildings and/or vessels. However, no such system has flown in space as yet. Such a system could be designed so that it reuses most (otherwise lost) nutrients. 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. The food coming from the crops is then consumed again by the system's users and the cycle continues.

Microbe detection and control[edit]

The NASA LOCAD (Lab-on-a-Chip Applications Development) project is working on systems to help detect bacterial and fungal growths in spacecraft used for long-duration spaceflight.[4]

Space vehicle systems[edit]

Gemini, Mercury, & Apollo[edit]

American Mercury, Gemini and Apollo spacecraft contained 100% oxygen atmospheres, suitable for short duration missions, to minimize weight and complexity.[5]

Space Shuttle[edit]

The Space Shuttle was the first American spacecraft to have an Earth-like atmospheric mixture, 22% and 78%.[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. The Shuttle Reference Manual contains ECLSS sections on: Crew Compartment Cabin Pressurization, Cabin Air Revitalization, Water Coolant Loop System, Active Thermal Control System, Supply and Waste Water, Waste Collection System, Waste Water Tank, Airlock Support, Extravehicular Mobility Units, Crew Altitude Protection System, and Radioisotope Thermoelectric Generator Cooling and Gaseous Nitrogen Purge for Payloads.[6]

Orion crew module[edit]

The Orion crew module life support system is being designed by Lockheed Martin in Houston, Texas.[citation needed]

Soyuz[edit]

The life support system on the Soyuz spacecraft is called the Kompleks Sredstv Obespecheniya Zhiznideyatelnosti (KSOZh).[citation needed] Vostok, Voshkod and Soyuz contained air-like mixtures at approx 101kPa (14.7 psi).[5]

Plug and play[edit]

The Paragon Space Development Corporation is developing a plug and play ECLSS called commercial crew transport-air revitalization system (CCT-ARS)[7] for future spacecraft partially paid for using NASA's Commercial Crew Development (CCDev) money.[8]

The CCT-ARS provides seven primary spacecraft life support functions in a highly integrated and reliable system: Air temperature control, Humidity removal, Carbon dioxide removal, Trace contaminant removal, Post-fire atmospheric recovery, Air filtration, and Cabin air circulation.[9]

Space station systems[edit]

Skylab[edit]

Because of fire risk and potential physiologic effects, Skylab used 28% Oxygen and 72% Nitrogen.[5]

Spacelab[edit]

Mir[edit]

The Mir and Salyut space stations contained an air-like Oxygen and Nitrogen mixture at approximately sea-level pressures of 93.1 kPa (13.5psi) to 129 kPa (18.8 psi) with an Oxygen content of 21% to 40%.[5]

International Space Station[edit]

Main article: ISS ECLSS

Bigelow commercial space station[edit]

The life support system for the Bigelow Commercial Space Station is being designed by Bigelow Aerospace in Las Vegas, Nevada. The space station will be constructed of habitable Sundancer and BA 330 expandable spacecraft modules. As of October 2010, "human-in-the-loop testing of the environmental control and life support system (ECLSS)" for Sundancer has begun.[10]

EVA systems[edit]

Extra-vehicular activity (EVA) systems primarily consist of the traditional space suit, but can also include self-contained individual spacecraft.[citation needed]

Space suits[edit]

Both space suit models currently in use, the U.S. EMU and the Russian Orlan, include Primary Life Support Systems (PLSSs) allowing the user to work independently without an umbilical connection from a spacecraft. A space suit must provide life support, either through an umbilical connection or an independent PLSS.[citation needed]

Natural systems[edit]

Natural LSS like the Biosphere 2 in Arizona have been tested for future space travel or colonization. These systems are also known as closed ecological systems. They have the advantage of using solar energy as primary energy only and being independent from logistical support with fuel. Natural systems have the highest degree of efficiency due to integration of multiple functions. They also provide the proper ambience for humans which is necessary for a longer stay in space.

MELiSSA[edit]

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 manned space missions

See also[edit]

Footnotes[edit]

References[edit]

Further reading[edit]

  • Eckart, Peter. Spaceflight Life Support and Biospherics. Torrance, CA: Microcosm Press; 1996. ISBN 1-881883-04-3.
  • Larson, Wiley J. and Pranke, Linda K., eds. Human Spaceflight: Mission Analysis and Design. New York: McGraw Hill; 1999. ISBN 0-07-236811-X.
  • Reed, Ronald D. and Coulter, Gary R. Physiology of Spaceflight – Chapter 5: 103–132.
  • Eckart, Peter and Doll, Susan. Environmental Control and Life Support System (ECLSS) – Chapter 17: 539–572.
  • Griffin, Brand N., Spampinato, Phil, and Wilde, Richard C. Extravehicular Activity Systems – Chapter 22: 707–738.
  • Wieland, Paul O., Designing for Human Presence in Space: An Introduction to Environmental Control and Life Support Systems. National Aeronautics and Space Administration, NASA Reference Publication RP-1324, 1994

External links[edit]


Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Life_support_system — Please support Wikipedia.
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4169 news items

 
West Hawaii Today
Fri, 31 Jul 2015 17:11:15 -0700

Make plans in advance to go to a safe location where electricity will be available if someone in your home depends on an electrically powered life support system and you don't have a backup generator. Some shelters are designed for people with health ...

PCWorld

PCWorld
Sat, 01 Aug 2015 06:52:30 -0700

It makes for some interesting trade-offs, like "Do I save some money and buy a life support system that uses both nitrogen and carbon dioxide, or do I spend a bit more for one that only burns carbon dioxide?" The latter uses fewer resources total, but ...

Napa Valley Register

Napa Valley Register
Mon, 27 Jul 2015 15:22:27 -0700

The next morning, after another CAT scan and examination, the doctors reported that their diagnosis had not changed and that only the life support system was keeping her going,” he said. After an “anguished discussion” with family and friends, Sherrill ...

The Star Beacon

The Star Beacon
Sat, 01 Aug 2015 05:00:00 -0700

1, the new ambulance is fully equipped with state-of-the-art equipment and a Lucas CPR life support system, which was donated by a local family and the Saybrook Firefighters Association. The former ambulance from Station No. 2 will be retrofitted to ...

Huffington Post

Huffington Post
Fri, 31 Jul 2015 12:35:59 -0700

Given we are now a global human society where innovations spread like wildfire and impacts include altering Earth's life support system a greater degree of thought towards unintended consequences is probably in order. Humanity has already had one lucky ...

The News Herald

The News Herald
Thu, 30 Jul 2015 17:00:00 -0700

It is a life support system for Navy divers that will allow for faster mission times and increased safety. The prototype got its name from the middle name of Greg Eugene Holbrook, a senior engineer at NSWC PC who helped in testing. The Eugene system ...
 
BaltimoreRavens.com
Fri, 31 Jul 2015 14:11:15 -0700

And she goes, 'You need to read through this and sign this.' He says, 'Well, can you explain to me what it is?' She says, 'Yes, it's in case things don't go right, you're on the life support system. If we have to pull the plug, we want your permission ...

Chicago Tribune

Chicago Tribune
Sun, 12 Jul 2015 10:43:01 -0700

The zoo said the habitat's life-support system apparently malfunctioned around midday Friday. "They are taking it apart piece by piece to see what went wrong," said Bill Zeigler, senior vice president of animal programs for the Chicago Zoological ...
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