{"id":260,"date":"2014-06-24T06:54:37","date_gmt":"2014-06-24T06:54:37","guid":{"rendered":"https:\/\/www.sustainspace.com\/?p=260"},"modified":"2024-03-07T03:07:57","modified_gmt":"2024-03-07T03:07:57","slug":"nasa-targets-90-greywater-efficiency","status":"publish","type":"post","link":"https:\/\/www.sustainspace.com\/?p=260","title":{"rendered":"NASA Targets Reduced Water Usage for Long Duration Missions"},"content":{"rendered":"
\"NASA<\/a>

Water Recovery System (credit: NASA)<\/p><\/div>\n

Water is essential for human survival on Earth and\u00a0in space. A typical person requires between 3.5 to 15 liters per day. Yet launching large quantities of water up to the International Space Station (ISS) is terribly expensive, and would be a major impediment to future space settlement. So NASA has made water recycling\u00a0a vital part of closing the life support “loop”. Meanwhile, water is often in short supply even on the Earth, especially in a clean, drinkable form<\/span>.<\/p>\n

<\/p>\n

First Steps<\/h4>\n

Russia\u2019s space station Mir recycled cosmonaut sweat.\u00a0<\/span><\/span>An earlier NASA method of water re-use\u00a0involved separating waste water into hydrogen and oxygen. The oxygen could be used for breathing and thus reduce the\u00a0amount of oxygen that needed to be transported to ISS (NASA 2008<\/a>).<\/p>\n

NASA’s Current System on the ISS<\/h4>\n

NASA’s current water recycling system on ISS is the Water Recovery System (WRS)<\/a>, part of the Environmental Control and Life Support System (ECLSS). WRS\u00a0water purification machines on the ISS cleanse wastewater in a three-step process. WRS\u00a0first filters out particles and debris.\u00a0Then, urine is processed though vapour compression distillation (VCD)<\/span>, while humidity condensate\u00a0passes through multi-filtration beds to remove organic and inorganic impurities.<\/p>\n

Products of the vapour and multi-filtration are mixed together and passed\u00a0to<\/span>\u00a0a catalytic oxidation reactor that removes volatile organic compounds (VOC)\u00a0<\/span>and kills bacteria and viruses” (Carter at al. 2008<\/a>)<\/span>. This system is designed to recycle about 90% of ISS waste water. ISS occupants\u00a0are\u00a0supplied with hydrated food that makes up the remaining 10%.<\/p>\n

\"Watertech<\/a>

(credit: Watertech International)<\/p><\/div>\n

Similar\u00a0technology is also being used in the field.\u00a0Waterlife International<\/a>\u00a0produces a unit for local use. They have engaged in projects in Kenya, Rwanda, South Sudan and Cambodia. They are\u00a0in talks to supply a provincial government in South Africa.\u00a0Also see the\u00a0Water Security Corporation<\/a>.<\/p>\n

Next Generation System<\/h4>\n

To do even better, the\u00a0Alternative Water Processor (AWP) is currently being developed by NASA’s Next Generation Life Support Project<\/a>,\u00a0under the Game Changing Development Program<\/a>. \u00a0It will support a crew of four each with 11 liters of water per day on a long-duration space flight mission. On such missions, food will likely be freeze-dried rather than hydrated, so it\u00a0will not be available as a source of water. Hence, the newer\u00a0AWP must have an even higher recovery rate than the older WRS.<\/span><\/p>\n

AWP has a membrane-aerated bioreactor to destroy organic contaminate\u00a0and a forward osmosis secondary treatment (FOST) system to remove dissolved solids. FOST uses saltwater as the drawing solution, t<\/span>hen reverse osmosis is used to remove the salt, according to Michael Flynn, a research engineer at the NASA Ames Research Center.\u00a0\u00a0(Also see\u00a0NASA 2013<\/a>)<\/span><\/p>\n

\"Water<\/a>

FOST\u00a0water processor\u00a0(image credit NASA)<\/p><\/div>\n

Construction of the first generation FOST was recently\u00a0completed at the NASA Ames Research Center. The \u00a0system recently shipped to the NASA’s Johnson Space Center. FOST will undergo integrated testing with the membrane-aerated bioreactor, designed by Texas Tech University and constructed by NASA Johnson Space Center. \u00a0(NASA 2013<\/a>)<\/p>\n

“Inside the water recovery system is an evolving set of technologies with great promise,” said \u00a0Flynn. “Ultimately, these systems will continue to evolve and become increasingly more complex, integrated and smaller.”\u00a0\u00a0(NASA 2013<\/a>)\u00a0<\/span>The new system has two major advantages. First, it allows for 95% recycling of waste water.\u00a0Part of this improvement is due to the use of\u00a0bioreactor to treat\u00a0urine, which will avoid the need for highly toxic\u00a0chromic acid<\/span>. Second, the\u00a0new system\u00a0also processes a higher\u00a0volume of waste water, so that crew will be able to engage in a greater range of water usage, such as hand-washing and laundry. Also, this new system\u00a0is lighter, takes up less space and requires less energy per gallon processed, so it is better-suited for long-duration missions.<\/p>\n

Bringing It Back to Earth<\/h4>\n
\"Sustainability<\/a>

Sustainability Base water recycling system<\/p><\/div>\n

NASA’s FOST system is already finding use on Earth. NASA researchers installed a larger version of FOST in its Sustainability Base<\/a>, which\u00a0in combination with other water-saving technologies integrated into the building, is expected to reduce greywater consumption by more than 90 percent. (Total tap water usage is reduced by 40%.)\u00a0Flynn points out that additional capabilities of FOST in the Sustainability Base include\u00a0the ability to do long duration testing and\u00a0failure prediction. It is certainly safer to do this on Earth than in space.<\/p>\n

The Future<\/h4>\n

NASA’s next step may take inspiration from living systems, according to Flynn. Biomimicry is a form of engineering that imitates living systems. For example, in the human body, the small intestine is a highly efficient water absorption and filtering system that works reliably for many decades. It is also self-repairing. NASA is looking towards designing a system that emulates the positive qualities of the small intestine.<\/p>\n

A Brief Lesson in Water Filtering<\/strong><\/h4>\n

Knowing a few terms can help understand NASA’s technology.\u00a0Water is typically recycled from several sources.\u00a0Greywater<\/em>\u00a0is waste water from showers and sinks, and can include water\u00a0from humidity.\u00a0Blackwater<\/em>\u00a0contains fecal matter and urine, such as\u00a0from toilets. \u00a0Reverse osmosis<\/em>\u00a0(RO) uses physical pressure to push water through a filter. In contrast, forward osmosis<\/em>\u00a0(FO) draws water through a filter using an ionic medium such as sugar or salt water, and has several advantages, such as reduced pore clogging.<\/p>\n","protected":false},"excerpt":{"rendered":"

Water is essential for human survival on Earth and\u00a0in space. A typical person requires between 3.5 to 15 liters per day. Yet launching large quantities of water up to the International Space Station (ISS) is terribly expensive, and would be a major impediment to future space settlement. So NASA has made water recycling\u00a0a vital part […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[39,37,40,36,38],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.sustainspace.com\/index.php?rest_route=\/wp\/v2\/posts\/260"}],"collection":[{"href":"https:\/\/www.sustainspace.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sustainspace.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sustainspace.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sustainspace.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=260"}],"version-history":[{"count":10,"href":"https:\/\/www.sustainspace.com\/index.php?rest_route=\/wp\/v2\/posts\/260\/revisions"}],"predecessor-version":[{"id":962,"href":"https:\/\/www.sustainspace.com\/index.php?rest_route=\/wp\/v2\/posts\/260\/revisions\/962"}],"wp:attachment":[{"href":"https:\/\/www.sustainspace.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=260"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sustainspace.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=260"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sustainspace.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=260"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}