An American astronaut from the space shuttle Discovery has successfully completed a risky repair mission on the underside of the shuttle.
American astronaut Steve Robinson today (Wednesday) pulled-out two dangling pieces of "gap filler," which insulates the areas between the craft's thermal tiles. He performed the maneuver on the robotic arm of the International Space Station.
It was the first time an astronaut has ever ventured to the underside of an orbiting spacecraft.
The emergency spacewalk came after officials at the U.S. space agency NASA 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.