NASA scientists are testing water treatment technology that would allow astronauts to convert both sweat and urine into drinkable water.

Employees at the Marshall Space Flight Center in Huntsville, Ala., have begun a six-week trial of the latest water treatment equipment in hopes it will allow missions to the moon and later Mars to be extended without the expense of launching resupply ships.

The new system, called the Exploration Water Recovery System, is a combination of air- and water-purification technologies designed to squeeze every last drop of water from physical activity and bodily functions.

For the study, 20 employees exercise an hour a day on treadmills, rowing machines and other equipment to generate water vapour through perspiration and respiration. Individuals also donate urine as part of the test.

NASA is scheduled toinstall a Russian-built toilet systemthatcan turn urine intodrinking wateron the International Space Station. The toilet, which costs $19 million US, will be delivered to the station in 2008.

NASA'sresearch is part ofthe space agency'slarger plan to establish a permanent settlement on the moon by the year 2024. It's a challenge, said exploration life support project manager Monsi Roman, because the moon lies over 360,000 kilometres away.

"Our hope is to mature current life support technologies to be able minimize the amount of materials we need to bring up to space to support future crews," Roman said in a statement.

NASA's timeline calls for the testing of its first spaceships in 2009; making the first manned flight of its new Orion spacecraftin 2014; landing the first four-person crew on the moon in 2020; and establishing its own moon base in 2024.