The international space station is about to get all the comforts of a modern, high-end, "green" home: a fancy recycling water filter, a new fridge, extra bedrooms, workout equipment and the essential half-bath.

Later this week, space shuttle Endeavour's seven astronauts will carry up all the frills for more luxurious space station living - and a larger household. Liftoff is set for Friday night, US time.

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It will be a home makeover in the extreme. The space station will go from a three-bedroom, one-bath house with kitchenette to a five-bedroom, two-bath house with two kitchenettes and the latest gizmos Nasa has to offer.

To be more precise, astronauts will be installing an extra toilet, more sleeping compartments with individual thermostats and laptop hookups, and an exercise machine capable of some 30 routines.

They also will be delivering the essentials of Nasa's first attempt at a closed-loop environmental system in orbit, where almost everything gets recycled. Already, the power on the space station is generated from solar panels.

Most significant is the water recovery system - it will turn urine and condensation into fresh drinking water. The system is essential if Nasa is to increase the size of the space station crew from three to six. That switch is supposed to occur by the middle of next year.

Endeavour's commander, Christopher Ferguson, considers the water system the single most important piece of equipment that he's delivering. He said the benefits go way beyond the space station - think of all the deep-space exploration made possible once crews are freed of lugging water.

"This is really it, and it has no parallel. I would challenge you to find any other system on the Earth that recycles urine into drinkable water. It's such a repulsive concept that nobody would even broach it."

"But that day will come on this planet, too, where we're going to need to have these technologies in place, and this is just a great way to get started."

Would he drink the stuff?

"Are you crazy? I would never try that," Ferguson joked. "No, actually, you know what? If they offered me a sample, I would do it."

Astronaut Donald Pettit, a former space station resident who will help hook up the system, looks at it as one big coffee machine.

"It's going to take yesterday's coffee and make it into today's coffee," Pettit said.

Hot coffee is no problem in orbit, it's the cold drinks that are scarce.

The existing space station galley provides hot or warm water - but not cold. The same with food - hot or warm, but nothing cold. Fresh food like apples or onions that go up on Russian supply ships or Nasa's shuttles has to be gobbled up quickly. The lone refrigerator is restricted to science experiments. So the astronauts are quite excited about getting a second refrigerator with the new kitchenette. It will keep drinks cold and food fresh.

"It seems kind of trivial, but six months of lukewarm orange juice can kind of bum you out," said astronaut Sandra Magnus, who will fly up on Endeavour and move in for 3 months.

Nasa does not expect to get the water generation system up and running before spring. That's how long it will take to check everything and make sure the recycled water is safe to drink. Until then, the space station crew will continue to use water delivered by the shuttle and unmanned Russian supply ships.

Before Endeavour leaves, urine already collected by space station residents will be flushed through the system and undergo distillation, so recycled water samples can be returned to Earth for analysis. Additional samples will be brought back by another shuttle in February to make absolutely certain the system is working properly.

If everything goes well, the space station will open its doors to six full-time residents next May or June.

The jump in crew size is especially important for the Canadian, European and Japanese astronauts who have been waiting years to live aboard the space station.

"Imagine for a moment that we have an international space station in orbit that we've invested in and we don't have any US crews on board. That's what the partners live with today," said Mike Suffredini, Nasa's space station program manager.

Besides providing patriotic public relations, the larger, more diverse crew will boost the amount time spent on scientific research from 10 hours a week - the average now - to 35 hours a week, Suffredini said. Most of the crew's time is now devoted to upkeep, and the maintenance chores will grow as the 10-year-old space station ages, he noted.

While fixing up the inside of the space station, Endeavour's astronauts will tackle a greasy, grimy job on the outside. Three of the crew will take turns cleaning and lubricating a jammed solar-wing rotating joint; it's clogged with metal shavings from grinding parts and hasn't worked right for more than a year.