CAPE CANAVERAL, Fla. — Spacewalking astronauts relied on brute force Wednesday to remove a broken coolant pump that has hampered operations at the international space station.
Astronauts Douglas Wheelock and Tracy Caldwell Dyson’s first attempt at emergency repairs to the cooling system was thwarted last weekend by a large ammonia leak. This time, to everyone’s relief, there was no burst of toxic ammonia from a stubborn connector, just a few frozen flakes that drifted harmlessly away.
Dyson, who helped her electrician father when she was young, had little trouble unhooking power and data cables on the pump.
“My dad would be proud,” she said.
The urgent repair job is considered one of the most challenging in the 12-year history of the space station. The cooling system is crucial for keeping electronics from overheating, and half of the system was knocked out when the ammonia pump failed 1 1/2 weeks ago. Science research is on hold and unnecessary equipment is off until the pump can be replaced. Engineers suspect an electrical short in the pump led to the shutdown.
A spare pump will be installed during a third spacewalk Sunday.
