Astronaut Steve Robinson took what he called "the ride of the century" yesterday to complete audacious in-flight repairs to the shuttle Discovery and restore some prestige to Nasa's otherwise troublesome return to space.
Dangling on the end of the international space station's robotic arm, 224 miles above Earth, Robinson plucked two pieces of protruding cloth "gap-filler" from between the tiles of the shuttle's underside heat protection shield.
The spacewalk was ordered because of fears that the orbiter might overheat on re-entry to Earth's atmosphere.
"It looks like this big patient is cured," Robinson said as he completed Nasa's first in-orbit repair to a spacecraft. He removed the two inch-long fragments using his fingers instead of resorting to a homemade hacksaw he had in reserve.
The euphoria was in marked contrast to the dark cloud that has lingered over the 13-day mission since a large chunk of insulating foam broke away at lift-off, the same problem that doomed the shuttle Columbia and its seven astronauts in February 2003.
"It's a real highlight in the careers of each one of us today," said astronaut Mike Massimino, who handled communications with crew from mission control in Houston, Texas.
Paul Hill, lead flight director for the mission, said that Discovery was clear to attempt re-entry pending further investigation of one remaining potential safety issue, a bulging fabric insulation "blanket" beneath a cabin window. He refused to rule out a fourth spacewalk.
Yesterday's success will buoy Nasa's engineers, who are struggling to fix the falling foam problem. The space agency, which spent $1.4bn (£780m) on safety improvements since the Columbia disaster, says the ageing shuttle fleet will not fly again until a solution is found.