Space Station Residents To Drink Purified Urine

As NASA prepares to double the number of astronauts living aboard the international space station, nothing may do more for crew bonding than a machine launched aboard the space shuttle Endeavour on Friday.

It's a water-recycling device that will process the crew's urine for communal consumption.

"We did blind taste tests of the water," said NASA's Bob Bagdigian, the system's lead engineer. "Nobody had any strong objections. Other than a faint taste of iodine, it is just as refreshing as any other kind of water.

"I've got some in my fridge," he added. "It tastes fine to me."

Delivery of the $250 million wastewater recycling gear is among the primary goals of NASA's 124th shuttle mission.

The shuttle was to arrive at the space station on Sunday so astronauts could begin 11 to 12 days of home improvements.

In addition to the water recycler, Endeavour carries two small bedrooms, the station's first refrigerator, new exercise gear and perhaps most important for a growing crew — a second toilet.

"With six people, you really do need to have a two-bathroom house. It's a lot more convenient and a lot more efficient," said Endeavour astronaut Sandra Magnus, who will take over as a space station flight engineer from Greg Chamitoff.

Also aboard the space station are U.S. astronaut Michael Fincke and cosmonaut Yury Lonchakov.

The space station's Russian-built toilet broke earlier this year, and the station's three residents had to manually flush it with extra water several times a day until a new pump was delivered by the space shuttle Discovery two weeks later.

NASA wants to make sure that the new water recycling system is working well before adding another three astronauts to the station's crew.

Reusing water will become essential once NASA retires its space shuttles, which produce water as a byproduct of their electrical systems. Rather than dumping the water overboard, NASA has been transferring it to the space station.

But the shuttle's days are numbered. Only 10 flights remain, including a final servicing call to the Hubble Space Telescope. NASA is preparing to end the program in 2010, after which a Russian Soyuz spacecraft will be the only way to ferry crew to the space station.

"We can't be delivering water all the time for six crew," said space station flight director Ron Spencer. "Recycling is a must."

NASA expects to process about 23 liters of water per day with the new device. The goal is to recover about 92 percent of the water from the crew's urine and moisture in the air.

The wastewater is processed using an extensive series of purification techniques, including distillation — which is somewhat tricky in microgravity — filtration, oxidation and ionization.

The final step is the addition of iodine to control microbial growth, Bagdigian said.

The device is intended to process a full day's worth of wastewater in less than 24 hours. "Today's drinking water was yesterday's waste," Bagdigian said.

(Reuters, MT)