NASA Advances Water Recycling for Space Travel, Earth Use

Nov. 15, 2004

At four agency centers across the country, NASA is studying several ways to recycle water in space, methods which may eventually be used in remote locations on Earth.

"Developing innovative life support technologies will reduce risks associated with human space exploration," said Eugene Trinh, director of the Human System Research and Technology Program, NASA Headquarters, Washington.

"We are working to improve technology used onboard the International Space Station (ISS) and have several research projects under way for future missions to the moon and Mars," he explained to Science Daily.

ISS crew members need to save as much water as possible. Each is allocated about two liters daily. They stretch the ration by collecting, cleaning and reusing wastewater, condensate in the air, and urine.

A new technology to improve recycling on the ISS is being developed by engineers at Hamilton Sundstrand Space Systems International, Inc., Windsor Locks, Conn., and researchers at NASA's Marshall Space Flight Center (MSFC), Huntsville, Ala.

The Water Processor Assembly (WPA) will be the first major hardware delivery of the Regenerative Environmental Control Life Support System. The WPA and the Urine Processor Assembly make up the Water Recovery System (WRS), which feeds the Oxygen Generation System.

These combined systems will support as many as seven crew members.

"The Water Processing Assembly can daily produce 35 gallons of potable recycled water," said Bob Bagdigian, MSFC Regenerative Environmental Control and Life Support System Project Manager.

After the new systems are installed, annual delivered water to the ISS should decrease by approximately 15,960 pounds, about 1,600 gallons. The WPA is scheduled for delivery in 2008.

More important than the amount of water is its purity. Chemical and microbial contaminants make it unappetizing or unhealthy, and it can clog complicated fluid systems. The Aerobic Rotational Membrane System (ARMS) research project at NASA's Kennedy Space Center (KSC), Fla., may help.

"We're trying to move toward a biological treatment method using bacteria to help cleanse the water," said Tony Rector, Dynamac Corp. bioprocess engineer at KSC.

The KSC prototype shop fabricated a model of the system. It is being tested inside KSC's Space Life Sciences Laboratory, and Rector and colleagues designed it.

At NASA's Ames Research Center (ARC), Moffett Field, Calif., a water recycler enabling reuse for three years without resupply is being developed on a timeline to fit into exploration plans, according to ARC scientist Michael Flynn. A preliminary engineering development unit can hourly recycle more than 13 pounds, about one gallon, of waste into potable water.

"If we were going to Mars tomorrow, this is the water treatment system astronauts might well use," Flynn said. He is developing the system in cooperation with Water Reuse Technology, Inc., Garden Valley, Calif.

"This unit can enable a six-person crew to shower, wash clothes and dishes, drink water and flush toilets over three years without resupply," Flynn said.

Engineers at NASA's Johnson Space Center (JSC) in Houston are developing technology to help astronauts live in space. They are studying ways to reduce the size of biological water processors.

JSC microbiologist Leticia Vega is working to make biological water processors modular, so they can be more easily removed and cleaned. Researchers also are identifying soaps that rapidly degrade at high concentrations.

Cleansers, such as shampoo and soap, affect the size of systems because of the time it takes for them to break down. That's why researchers are studying ways of optimizing size of ion exchange beds used for the final purification of water.

Water recycling technologies developed by NASA will undergo combined water recovery systems testing at JSC to meet exploration timelines.

Many of these recycling technologies also may have Earth-based uses. NASA is working with the Expeditionary Unit Water Purification Program of the U.S. Office of Naval Research and Bureau of Reclamation to explore ways to use recycling in remote locations.

Source: Space Daily