When the waste filled spacecraft enters Earth atmosphere
Life Support in Space
Above: Image of the ECLSS by James E. Scarborough, Wikimedia Commons
People need air, water and food to survive. On Earth, different parts of ecosystems provide these basic needs. For example, because plants add essential oxygen to the atmosphere and remove toxic carbon dioxide, they help keep our air breathable. Drinking water canada goose outlet comes from lakes, rivers and groundwater. Soil feeds the crop plants that are harvested to feed people.
With respect to the matter that makes up air, water and food, the Earth is a closed system. Matter is not added to the Earth from space, or lost to space from the Earth. All the matter is recycled within the global ecosystem.
On the ISS, the American ECLSS manages the atmosphere (air quality, humidity, temperature and pressure), water (waste water treatment and drinking water production), emergency services (such as detecting and controlling fires and toxic spills), and waste (collection and storage).
The International Space Station (ISS) orbits Earth 400 kilometres above the planet surface. canada goose outlet uk sale Astronauts on the ISS need air, water and food, but there are no ecosystems in space to provide these basic needs. The ISS life support systems generate and recycle some, but not canada goose outlet jackets all, oxygen and water. All food is sent from Earth. Because the ISS is dependent on Earth for canada goose coats its full life support needs, it is an open system.
NASA Environmental Control and Life Support (ECLSS) is a system of interconnected and interdependent machines that provide breathable air and pure canada goose outlet sale drinking water for astronauts on the ISS. Machines built by the Russian Federal Space Agency (Roscosmos) also provide some ISS life support.
Air on the ISS
Breathable air contains oxygen Canada Goose Jackets and very little carbon dioxide. The Oxygen Generating Assembly (OGA) of ECLSS makes oxygen by separating liquid water into hydrogen and oxygen gas, canada goose outlet shop using electricity from the ISS solar panels. ECLSS removes toxic carbon dioxide from inside the ISS using filters.
The Russian Elektron system makes oxygen by water electrolysis, just like the ECLSS. Vozdukh is the Russian system that removes carbon dioxide from the ISS air.
Waste carbon dioxide, along with waste hydrogen Canada Goose Online from the OGA, used to be vented into space. In 2010, the addition of the Carbon Dioxide Reduction, canada goose outlet new york city also called the Sabatier, was a big step towards a closed oxygen recycling system. The Sabatier uses the waste carbon dioxide and hydrogen official canada goose outlet gases to make water, which is eventually returned to the OGA to make oxygen again. (Methane gas is a second product of the Sabatier reaction; it is vented into space.)
The Sabatier is not perfectly efficient; about half of the oxygen can be recovered from the waste carbon dioxide. NASA is working to improve this efficiency. In the meantime, tanks of oxygen are sent from Earth on resupply vehicles, and the ISS is stocked with special emergency back up candles that release oxygen when they are burned.
ECLSS reclaims around 90% of the water used by astronauts and purifies it into clean drinking water. The Water Processor Assembly (WPA) collects water from the Sabatier, used water from washing, condensed water vapour from the air (humidity from sweating), and even urine. The WPA produces pure water for drinking, meal preparation, hand washing, showering, and oxygen production in the OGA.
Some containers of water are still sent from Earth on resupply vehicles, but water recycling by the ECLSS is approaching a closed system. NASA goal is to improve the ECLSS so that the air and water systems are completely integrated and function as a closed loop, recycling or regenerating all the air and water that astronauts need.
Food on the ISS
Everything that astronauts eat on the ISS is sent from Earth, so this is a completely open system. Currently, most space food is ready to eat or pre cooked. Resupply vehicles bring a limited amount of fresh fruit and vegetables, which are a delicious dietary treat for the astronauts.
NASA is learning how to grow fresh produce in space using its Vegetable Production, dubbed Veggie. ISS astronauts tasted space grown lettuce for the first time in August canada goose uk outlet 2015. More recent Veggie experiments involved growing canada goose outlet online zinnias not edible, but a good test for other plants, such as tomatoes, that must flower for fruit production.
Space Food: Feeding Astronauts on the ISS and Beyond
Being able to grow some fresh fruits and vegetables in space will be important for future long term missions, like a voyage to Mars. In theory, plants can also help maintain air quality on spacecraft through photosynthesis buy canada goose jacket cheap (plants take in carbon dioxide and produce cheap canada goose oxygen). Currently, this is not a significant contribution because only a few plants can be canada goose clearance sale grown at a time.
Waste on the ISS
Solid waste on the ISS includes packaging, containers, trash (such https://www.baertakreation.de as plastic bags, hygiene wipes, used clothing), and fecal waste. All waste is gathered and stored until is it put into an empty canada goose uk shop resupply vehicle after cargo delivery. When the waste filled spacecraft enters Earth atmosphere, everything including the vehicle burns up. Waste management is an open system because all waste is sent back toward Earth.
NASA is trying to reduce the amount of waste by using less packaging and developing ways to repurpose packaging material in space. For example, some packaging could be reused as is or melted into tiles for building shelters. This will be most important for future long term missions, canada goose outlet uk like going to Mars.
Fully Closed Life Support MELiSSA is Working on it
The University of Guelph in Ontario is one of the international partners for MELiSSA, with expertise in growing plants in closed environments.
The European Space Agency (ESA) is coordinating an international research project called the Micro Ecological Life Support Alternative, or MELiSSA. The goal is a completely closed life support system that could be used for future space travel. MELiSSA is canada goose outlet toronto factory an artificial ecosystem, modeled on an aquatic ecosystem. A functioning MELiSSA would use plants and algae to recover food, water and oxygen from human waste and carbon dioxide, using light energy for photosynthesis. This complete integration of canada goose outlet parka air, water, food and waste is still in the experimental phase.
Long term space missions will probably happen before a fully canada goose closed life support system, like MELiSSA, is ready to go. For the trip to Mars, the Reuse, Recycle philosophy will be important for designing a life support system that is as closed as possible.
For the purpose of this backgrounder, a closed system is a system that does not exchange matter with its surrounding matter is recycled within the system. A broader definition includes the exchange of energy (see Open system).