Discovery astronaut Steve Robinson was the first astronaut in the 24-year shuttle program to spacewalk to a shuttle's underside and, once there, the first to fix the heat shield while in flight. All of this was shown live on Internet station NASA TV. You can visit our Internet TV listing to watch NASA TV.

Robinson climbed onto the space station's robot arm and floated to the space shuttle's underbelly this morning to make the repair. Robinson gently pulled potentially hazardous filler material sticking out from between tiles on the shuttle. The size of these intrusions required that they be fixed before returning to Earth.

Robinson wore wireless mounted camera that provided a spectacular view of the shuttle's underside.

The spacewalk began at 4:48 a.m. ET and is expected to wrap up about 11:48 a.m. ET.