Space station astronauts make hasty outside repair

CAPE CANAVERAL, Fla. -- Astronauts making a rare, hastily planned spacewalk replaced a pump outside the International Space Station Saturday in hopes of plugging a serious ammonia leak.

The prospects of success grew as the minutes passed and no frozen flecks of ammonia appeared. Mission Control said it appeared as though the leak was plugged, although more monitoring will be needed before declaring a victory.

Christopher Cassidy and Thomas Marshburn installed the new pump after removing the old one suspected of spewing flakes of frozen ammonia coolant two days earlier. They uncovered "no smoking guns" responsible for the leak and consequently kept a sharp lookout for any icy flecks that might appear from the massive frame that holds the solar panels on the left side.

"No snow," the astronauts radioed.

NASA said the leak, while significant, never jeopardized crew safety. The space agency had never before staged such a fast, impromptu outside mission for a station crew. But managers wanted to deal with the trouble while it was fresh and before Marshburn returns to Earth in a few days. -- AP