Like handymen caulking a bathtub, two spacewalking astronauts squirted pink putty into deliberately damaged tile samples to test a new technique for repairing the space shuttle's fragile heat shield.
NASA declared the experiment a huge success. "We're just thrilled with the way it turned out," Zebulon Scoville, Endeavour's lead spacewalk officer, said early Friday after the 6 1/2 -hour spacewalk ended.
The space agency has been researching repair techniques since the shuttle Columbia disintegrated in 2003, killing its seven astronauts. The putty method is the latest to be tested in orbit.