Space Shuttle Endeavour will take off for the International Space Station this Saturday, to deliver a device capable of recycling urine into water. This is one of the many devices needed to expand the ISS from a habitat of three people, into one that can fit six crew members. Other devices include two new sleeping compartments, various exercise gear, a toilet and a galley.

The $250 million urine recycling system will use a process of distilation, filterization, ionization and oxidization to turn "yesterday's coffee into today's coffee" as one NASA astronaut puts it.

The recycling system will first be tested in the zero-gravity environment, and the water will be sampled by engineers back on Earth, before being used by the astronauts on the space station. The device has already been tested on Earth, and samplers could not taste any difference between tap water and the water extracted out of urine.

Bob Bagdigian of NASA, oversees the development of the water recycling system. He explained that the only comment often heard about the recycled water is the faint taste of iodine, which is necessary to control microbial growth. "Other than that, it is just as refreshing as any other kind of water," Mr Bagdigian said. "I've got some in my fridge. It tastes fine to me."

"Some people may think it's downright disgusting, but if it's done correctly, you process water that's purer than what you drink here on Earth," said astronaut Heidemarie Stefanyshyn-Piper.

NASA has ten more flights left for the space shuttle program, and one single flight left for this year. The space shuttle program will retire in 2010.