Live In Orbit: Spacewalkers Finish Repairs

"Finally."

That was the word from Endeavour astronaut Steve Bowen after he finished a week-long bid to fix a faulty International Space Station solar wing rotary mechanism -- unprecedented repairs carried out over the course of four spacewalks.

"Thanks for your work," Mission Control said.

"Your welcome. Anytime -- although never on the SARJ again, I hope," Bowen said.

The station sports two Solar Alpha Rotary Joints -- 10-foot-diameter gears that turn massive solar wings like paddlewheels so they can constantly track the sun as the station circles Earth. That enables the wings to maximize the amount of electrical power available to run station systems.

Working at the starboard end of the station's central truss, Bowen replaced the last of 11 trundle bearing assemblies on the starboard rotary joint. The bearing assemblies are located around the circumference of the big, round saw-tooth gear.

Then he reattached a thermal cover that protects the bearing -- the last step in a seven-day effort to fix the fouled-up joint, which has not been operating properly since September 2007.

Applause broke out in Mission Control.

"Looks great," said Endeavour pilot Eric Boe, who was directing the spacewalking work from a window perch inside the joined shuttle-station complex. "Outstanding work out there."

Engineers think inadequate lubrication caused the gear to grind against the trundle bearing assemblies, generating metal shavings that fouled the joint. Higher-than-normal vibrations and temperature readings prompted mission managers to order up inspections late last year.

A repair plan then was put in place and executed by Bowen and two other Endeavour astronauts: Shane Kimbrough and Heidemarie Stefanyshyn-Piper.

The starboard Solar Alpha Rotary Joint will be put through an auto-track test early Tuesday to see if the repairs worked.

You can watch the action unfold right here in The Flame Trench. Simply click the NASA TV box on the righthand side of the page to launch our NASA TV viewer and 24/7 coverage of the STS-126 mission.

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