Astronauts Encounter Glitches With Waste Treatment System

Friday was a relatively light day for the combined STS-126 and Expedition 18 crews onboard the International Space Station, as the astronauts paused from their more tedious activities ahead of a third planned spacewalk Saturday.

NASA reports the space shuttle and ISS crews worked on transferring, assembling and testing hardware at the station Friday. They also participated in a joint crew news conference.

Engineers are continuing to assess indications from sensors within the Water Recovery System that caused the Urine Processor Assembly to shut down during initial test operations Thursday and again Friday morning.

The system uses a rotating distillation process to separate out water from urine for further treatment. Sensors associated with the motor of the centrifuge within the processor showed the speed of the motor slowing and that the power the motor was using changed. NASA hopes a bad sensor is the cause of the problem -- there are spares onboard Endeavour -- and not a motor, which would need to be flown to the station on a future supply mission.

Still, station commander Mike Fincke told The Associated Press he wasn't surprised there were bugs in the brand-new system... and reiterated he wouldn't balk at drinking the treated result once the system was functioning normally. "It's just the water that's taken out," Fincke said during the news conference. "It's really clean and purified water. In fact, it's probably more pure than most people's tap water. So I'm not afraid to drink it."

Mission specialists Heide Stefanyshyn-Piper and Steve Bowen will camp out overnight in the station’s Quest Airlock in preparation for the third spacewalk of the mission. The purpose of this "camp out" is to purge the nitrogen from their bodies before their planned exit Saturday at 1:45 pm EST.

Piper and mission specialist Shane Kimbrough completed the mission’s second spacewalk Thursday, as ANN reported.

FMI: www.nasa.gov/station