Flight controllers today successfully activated a powerful pump on the space station's main solar power truss, pushing ammonia coolant through cold plates and into big radiators to keep critical electrical gear from overheating.

The pump activation was the final major step in a complex two-spacewalk re-wiring job to route solar array electricity through four big main bus switching units, transformers and other components making up the lab's permanent electrical system.

"Discovery, for EVA, not only do you have a good view you have something to celebrate," astronaut Stephen Robinson radioed from Houston. "The pump module activation went great for loop A, so you will not be R-and-R'ing any pump modules."

"Excellent, that's awesome news," drawled spacewalker Robert Curbeam.

"That's good news," agreed fellow spacewalker Sunita "Suni" Williams.

"Good job, guys," Curbeam added.

"And a nice job by the software engineers who did all that work a long time ago," Williams said.

Activation of the loop A cooling system was critical because the two main bus switching units at the heart of the channel 1/4 power circuitry would overheat if left on their own. An independent cooling system - loop B - was activated Thursday after Curbeam and Swedish astronaut Christer Fuglesang wired in the channel 2/3 MBSUs and transformers.

Flight controllers are now in the process of powering up space station systems that were shut down for today's re-wiring work.

Video coverage for subscribers only:
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VIDEO: DISCOVERY'S LAUNCH THROUGH FUEL TANK SEPARATION PLAY
VIDEO: SHORT CLIP OF DISCOVERY BLASTING OFF PLAY
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VIDEO: LONGER LENGTH MOVIE OF THE SCRUB PLAY
VIDEO: SCRUB CALLED DUE TO LOW CLOUDS PLAY
VIDEO: ASTRONAUTS DEPART QUARTERS FOR PAD PLAY
VIDEO: CREW FINISHES DONNING SPACESUITS PLAY
VIDEO: ASTRONAUTS IN DINING ROOM THURSDAY PLAY
VIDEO: PAD'S ROTATING SERVICE STRUCTURE ROLLED BACK PLAY
VIDEO: POST-ARRIVAL COMMENTS FROM THE CREW PLAY
VIDEO: ASTRONAUTS ARRIVE IN WAVE OF T-38 JETS PLAY
VIDEO: BIOGRAPHIES OF THE DISCOVERY ASTRONAUTS PLAY
VIDEO: NARRATED STS-116 MISSION PREVIEW MOVIE PLAY

VIDEO: WEDNESDAY'S SHUTTLE BRIEFING IN ITS ENTIRETY PLAY

BRIEFING SOUNDBITES:
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VIDEO: NOT YOUR FATHER'S FRR PLAY
VIDEO: READY TO RESUME NIGHT LAUNCHES PLAY
VIDEO: LAUNCH PREPS PROCEEDING WELL PLAY
VIDEO: YEAR-END ROLLOVER CONCERNS PLAY
VIDEO: REASSESSING TANK FOAM RISK PLAY
VIDEO: STATION SOLAR ARRAY DRIVE SYSTEM PROBLEM PLAY
VIDEO: PRESSURIZATION PRECAUTIONS AT THE PAD PLAY

VIDEO: OVERVIEW OF STS-116 MISSION PLAY
VIDEO: SHUTTLE/ISS PROGRAM PERSPECTIVE PLAY
VIDEO: PREVIEW OF MISSION'S SPACEWALKS PLAY
VIDEO: ASTRONAUTS' PRE-FLIGHT NEWS BRIEFING PLAY

VIDEO: COVERAGE OF PRACTICE COUNTDOWN ACTIVITIES PLAY

VIDEO: DISCOVERY ROLLS TO THE PAD PLAY
VIDEO: DISCOVERY MATED TO TANK AND BOOSTERS PLAY
VIDEO: SHUTTLE HOISTED VERTICALLY INSIDE VAB PLAY
VIDEO: DISCOVERY HAULED FROM HANGAR TO VAB PLAY
VIDEO: PORT 5 TRUSS PAYLOAD PACKED UP PLAY
VIDEO: CREW VISITS KENNEDY SPACE CENTER PLAY
VIDEO: EXTERNAL FUEL TANK MATED TO BOOSTERS PLAY
MORE: STS-116 VIDEO COVERAGE
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