Station coolant system back in business after third spacewalk

Doug Wheelock and Tracy Caldwell Dyson have capped a nearly 23-hour effort to restore the International Space Station's cooling system to full capacity with the completion of a third spacewalk today.

The pair returned inside the Quest airlock, plugged their spacesuits into station power supply and began to repressurize the airlock at 1:40 p.m. EDT, ending a seven-hour and 20-minute spacewalk.

"Hopefully we'll have a pump up and running and be back in business as a space station," Wheelock radioed after thanking teams on the ground for their help.

"Copy all, guys, great job," astronaut Ricky Arnold replied from Houston. "We're going to have a lot cooler station here shortly."

Today's efforts completed the removal and replacement of an ammonia pump that failed July 31, taking out half the cooling system serving U.S., European and Japanese facilities.

The new pump is functioning well, and systems that had to be shut down over the past 16 days are expected to be fully up and running by Thursday.

The spacewalk was the sixth for Wheelock, who cracked the top-10 list for most spacewalking time with a total of 43 hours and 30 minutes of extra-vehicular activity.

It was the third for Caldwell Dyson, whose total matched that of the pump replacement effort at 22 hours and 49 minutes. She ranks 61st all-time.

Other stats about the spacewalk:
-- It was the 150th supporting station assembly and maintenance since December 1998. Those collectively total 944 hours and 24 minutes.

-- It was the 242nd spacewalk ever by U.S. astronauts, and the 122nd based out of station airlocks. The latter group totals 757 hours and nine minutes.

-- Including an excursion by two Russian cosmonauts, the station's Expedition 24 crew has now completed four spacewalks totaling 29 hours and 31 minutes.