An experiment heading up next week to the space station could help landlubbers down here on Earth conserve water by doing a better job of filtering out chemicals, salts or other contaminants. It could even be a lifesaver for drought-stricken Californians who are desperate for new sources of water.
The water filtration experiment uses aquaporins, or tiny channels in human and plant cells, that only allow water molecules to pass in between the cell membrane.
In ground tests, the aquaporin membrane does a better job at filtering contaminants than the current activated carbon-based filter system on the International Space Station, according to Michael Flynn, a physical scientist at NASA's Ames Research Center.
Flynn says the new aquaporin filter would last longer, and eliminate the need to replace water filters on resupply missions.
"If you are going to Mars, there not going to have any resupply," Flynn said. "We need water supply systems to be very reliable and not have any replacement parts."
Right now, astronauts recycle all their water on ISS, including water extracted from urine, and water vapor from astronauts breathing that is exhaled into the tiny crew quarters.
However in recent months, the ISS crews have had to stop recycling their water because of delays in the launch vehicles that were supposed to bring in the new filters.
There's also this. Over time, NASA has noticed a buildup of a non-toxic compound called diethyl phthalate, which Flynn describes as a "new-car smell" from decomposing gaskets, glues, plastics and rubber pieces inside the station.
Even though it doesn't pose a human health risk, the problem is that diethyl phthalate could be masking other potentially harmful chemicals in the water system.
The current carbon multi-filter bed system has had trouble removing this compound, Flynn explained, but the biomimetic aquaporin membrane has done a better job.
"It's not hazardous, but on space station we don't like unexpected things happening. We want to address it."
Danish astronaut Andreas Morgensen is scheduled to bring up the new water filtration system when he blasts off on a Soyuz rocket on September 2. The filter system is designed by the Danish tech firm Aquaporin.
CEO Peter Holme Jensen says that the filter uses something called positive osmosis to draw the water from one chamber to another.
Instead of pushing water through using pressure -- which is how reverse osmosis works to filter seawater for example, Aquaporin draws the water through by putting a sugar solution on one side of the membrane.
"It acts like a sponge to suck in the water," Jensen says. "(The astronauts) extract the water and drink as a sweetened beverage."
Aquaporin is also working with partners in China and Singapore to develop biomimetic membranes that can be used to in commercial desalinization projects.
He says the aquaporin membranes would likely be used to pre-treat seawater, helping reduce the clogging and fouling that occurs on regular synthetic desalinization membranes.
California residents will be getting their first taste of desalinated seawater next month when a private firm opens a $1 billion plant near San Diego. The facility is expected to provide 7 to 8 percent of the city's drinking water -- although at double the price of existing imported water supplies.
Flynn says the new biologically based membranes that use aquaporin channels could be used by homeowners who want to recycle their water with a long-lasting filter.
"If you look at membrane industry, having one that would not have to be replaced, that would be a huge accomplishment," Flynn said. "That's the direction the market is going in."