But Problems Continue With Water Reclamation Unit

Shuttle Endeavour astronauts spent seven hours Saturday working on the International Space Station's starboard Solar Alpha Rotary Joint. Things were going so well on the mission's third spacewalk that they wanted to extend it, but mission controllers instructed them to call it a day.

CNN reports Heidemarie Stefanyshyn-Piper and Steve Bowen have now cleaned about 330 of 360 degrees of the starboard joint, and had wanted to finish that job before coming back inside. When Bowen and fellow astronaut Shane Kimbough complete the task during Monday's fourth and final planned spacewalk of the mission, they'll move over and perform similar maintenance on the port side.

At a news conference at Johnson Space Center, lead spacewalk officer John Ray said, "We stayed at a very steady, even pace and got everything done we'd planned."

Repairing and cleaning the joints and their bearings were a major focus of shuttle mission STS-126, after discovery of metal filings on the outside of the bearings last year suggested metal-on-metal wear.

For months, the rotation of the solar array to track the position of the sun was disabled to avoid further damage, but the resulting reduction in generating capacity would have prevented full operation of the station, especially the Kibo module recently delivered from Japan.

Endeavour and her crew also brought parts for a major expansion of the living space on the station, and a water recovery system which recycles urine and sweat back into drinking water. The system has not worked properly because, after a couple hours, a centrifuge used in the distillation section has been heating up and hitting a speed sensor, triggering a shutdown.

The crew has removed grommets which isolate the device from the equipment rack and hard-mounted it instead. More tests will be conducted after ground controllers turn the system back on.

The last STS-126 spacewalk is scheduled to kick off at 1:45 pm EST Monday, and is slated to last 6.5 hours. In addition to wrapping up maintenance work on the SARJs, other tasks they will perform include installation of a video camera on the P1 truss and work on Kibo.

FMI: www.nasa.gov