Spacewalkers Step Through Excursion Outside Station

Spacewalking astronauts now are breezing through their excursion outside the International Space Station, disconnecting five electrical cables from a failed ammonia pump and loosening four bolts mounting it to the outpost's central truss.

Station flight engineer Tracy Caldwell-Dyson grunted as she wrestled the last of five cables free about three hours into a planned six-hour excursion outside the orbital complex.

"My Dad would be proud!" Caldwell-Dyson said.

"Awesome," spacewalk officer Oscar Koehler replied from Mission Control.

Wheelock now is headed to retrieve a payload attachment device that will be used to latch onto the 780-pound pump module, which is about the size of a bathtub. Caldwell-Dyson will finish unfastening the four bolts. Then the two astronauts will extract the pump from the starboard side of the station's central truss. The pump module will be temporarily stowed on the station's mobile rail cart.

A spare pump is to be installed during a spacewalk Sunday.