An American astronaut from the space shuttle Discovery has successfully completed a risky repair mission on the underside of the shuttle.
Attached to a robotic arm, astronaut Steve Robinson pulled-out two dangling pieces of "gap filler," which insulates the areas between the craft's thermal tiles.
It was the first time an astronaut has ever ventured to the underside of an orbiting spacecraft.
President Bush called the Discovery's crew early today-Wednesday to wish them well on the mission.
Later, officials at the U.S. space agency, NASA, said they were extremely pleased with the operation.
The emergency spacewalk came after NASA engineers said they were concerned that hot gasses could seep into the crevices of the dislodged gap fillers when the shuttle re-enters Earth's atmosphere.
Hot gasses pierced through a hole in the space shuttle Columbia in 2003, causing the spacecraft to disintegrate on re-entry. All seven astronauts were killed.
Information for this report is provided by AP.