The ten-year-old International Space Station was due for a few upgrades. It needs some more bedrooms, a new kitchen and another bathroom; last but not least it needed a more reliable water supply. Well now it has one, but it may make some people squirm.

The Endeavour crew, who will lift off Friday from Florida on a 15-day mission, will among other things be installing an apparatus on the ISS which will recycle urine into drinking water.

So far the station relies on shuttle transports of water, which come about four times a year. But considering that the U.S. spacecraft are retiring in about two years, recycling water is absolutely essential.

In a candid remark Endeavour astronaut Sandy Magnus said that “There is definitely a yuck factor,” but she took the time to explain the reality of the process. "We are not really drinking our own urine. We are drinking water that has been reclaimed from a process with urine as the input," she said.

In addition to the water recycler, the station will see a refrigerator being installed. It will chill liquids and store fresh fruits and vegetables which will be delivered by Russian Soyuz craft.

"It seems kind of trivial, but six months of lukewarm orange juice can kind of bum you out,” said Magnus who will supervise the installation of the water purifier on board the ISS through February.

The Endeavour shall liftoff from the Kennedy Space Center in Florida at 6:55 p.m. CST.

There are some weather issues, as a storm triggered by the cold front which passed through Houston earlier this week will reach Florida’s Atlantic coast on the weekend, resulting in 60% lower chances of favorable weather. It’s even worse on Saturday, but Sunday will see a dramatic improvement.

"The timing of the front is really going to be the major factor," said Kathy Winters, the shuttle’s weather officer, on Wednesday.

According to Chris Ferguson, the Endeavour’s commander, astronauts are in need of more living and working space. “I like to think of it in terms of turning the space station from a three-bedroom, one-bath outpost into a five-bedroom, two-bath orbiting laboratory from which we can conduct scientific research for years to come,” said Ferguson.

Japanese and European science modules were added to the station earlier this year. These labs were added to older American and Russian research modules. The last components for the station are going to be launched in 2010, at the same time as NASA’s retirement of the space shuttle.

The science modules will be underutilized, however if the station cannot house enough astronauts to run them, and the new recycler is part of the gear needed to support them.

Endeavour will return to Earth with the first samples of recycled water, where NASA experts will test them to see how effective the station’s water purity analyzer is.

After a few more rounds of testing samples brought by several shuttles including Discovery in February and a Russian Soyuz in April, NASA will decide if the water can be drunk.