On space walk, two astronauts remove bad ammonia pump
Cape Canaveral, Fla. • Astronauts removed an old space-station pump Saturday, sailing through the first of a series of urgent repair space walks to revive a crippled cooling line.
The two Americans on the crew, Rick Mastracchio and Michael Hopkins, successfully pulled out the ammonia pump with a bad valve well ahead of schedule. That task had been planned for the next space walk, originally scheduled for Monday but now delayed until Christmas Eve because of the need for a suit swap.
If Mastracchio and Hopkins keep up the quick work, two space walks may be enough to complete the installation of a spare pump and a third space walk will not be needed as originally anticipated.
Several hours after Saturday's space walk ended, Mission Control bumped space walk 2 to Tuesday to give Mastracchio enough time to prepare a spare suit. His original suit was compromised when he inadvertently turned on a water switch in the air lock at the end of Saturday's excursion. NASA officials said Saturday night that it's unclear whether a third space walk will be needed. A third space walk had been slated for Christmas Day before the latest turn of events. NASA requires a day off between space walks for astronaut rest.
The space station breakdown 10 days earlier left one of two identical cooling loops too cold and forced the astronauts to turn off all nonessential equipment inside the orbiting lab, bringing scientific research to a near-halt and leaving the station in a vulnerable state.
Mission Control wanted to keep the space walkers out even longer Saturday to get even further ahead, but a cold and uncomfortable Mastracchio requested to go back. The space walk ended after 5Â½ hours, an hour short on time but satisfyingly long on content.
Earlier, Mastracchio managed to unhook all the ammonia fluid and electrical lines on the pump with relative ease, occasionally releasing a flurry of frozen ammonia flakes that brushed against his suit. A small O-ring floated away, but he managed to retrieve it.
"I got it, I got it, I got it. Barely," Mastracchio said as he stretched out his hand.
Mastracchio, a seven-time space walker, and Hopkins, making his first, wore extra safety gear as they worked outside. NASA wanted to prevent a recurrence of the helmet flooding that nearly drowned an Italian astronaut last summer, so Saturday's space walkers had snorkels in their suits and water-absorbent pads in their helmets.
To everyone's relief, the space walkers remained dry while outside. But midway through the excursion, Mastracchio's toes were so cold that he had to crank up the heat in his boots.
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