In Happier News... The UPA Works! (NASA Thinks)

NASA reports astronauts Joseph Acaba and Richard Arnold ended the STS-119 mission's third spacewalk at 6:04 pm Eastern Time Monday.

The pair helped robotic arm operators relocate the Crew Equipment Translation Aid cart from the Port 1 to Starboard 1 truss segment -- freeing up room for the STS-127 crew to work, when Endeavour delivers them to the station in a few months -- and completed other minor tasks, some ahead of schedule.

The day was not without its frustrations, however. Chief among those woes were continued problems with the Port 3 unpressurized cargo carrier attachment system (UCCAS) outside the Kibo module. As ANN reported this weekend, an improperly installed pin is believed to have jammed the UCCAS deployment in a half-open, half-closed state. Further work on the problem during Monday's excursion failed to remedy the situation.

After struggling with the balky pin, the spacewalkers once again tied off the half-deployed UCCAS, in hopes the problem will be solved during a later spacewalk. A similar device that was to be installed on the starboard side of Kibo will remain stowed as well, until NASA has a better understanding of the problem on the port side.

In happier news for NASA, crews were able to conduct a successful run using the Urine Processor Assembly, after problems were encountered during an earlier "wet" test. This time around, the UPA collected 15 pounds of reclaimed drinking water. Samples will be returned aboard Discovery for analysis before crew members will be given the 'go' to drink the water aboard the station.

Outside the station, Acaba and Arnold successfully lubricated the 'gripper' assembly at the end of Canadarm2. The robotic arm is mounted to the station's exterior, and helps lift and maneuver cargo and new station segments from shuttle cargo bays.

Monday's spacewalk lasted six hours, 27 minutes, and was the final one scheduled for mission STS-119. The duration of the mission was shortened after the shuttle Discovery's launch was delayed a month by problems with the launch vehicle's hydrogen fuel systems.

Discovery is scheduled to undock from the ISS Wednesday, and will return to Earth on March 27. Crewmembers for the Expedition 19 mission -- who will help comprise the first six-person crew onboard the station -- will blast off from Baikonur Cosmodrome aboard a Soyuz TMA-14 capsule early Thursday morning.

FMI: www.nasa.gov/shuttle