As early as the late '60s and early '70s, "we knew that exploration away from the earth was going to require the recycling of water and oxygen," Bagdigian says. Russian cosmonauts have been collecting and recycling moisture out of cabin air systems since the Salyut 1 and Mir space stations, which launched in 1971 and 1986, respectively. The Russians also did some work developing electrolyzers that can convert water, via electrolysis, into gaseous hydrogen and oxygen. "They've incorporated these technologies into their side of the [International] Space Station," he says.
While none of this conjures up thirst-quenching images of cold, clear water flowing down a mountain stream, NASA did conduct some blind taste tests that compared the recycled drinking water with plain tap water as well as with tap water that had iodine added to it. On a scale of one to nine, none of the waters scored higher than five. The most typical reaction after drinking the recycled water was to notice the taste of the iodine. The version of the water-recovery system that will be installed on the ISS next year will feature an added step that scrubs the iodine out of the finished product.
In the end, the goal is to simulate the way nature recycles urine and other human by-products. "The difference is," Roman says, "in a station on the moon, you'll know whose urine you're drinking."