Pictures of Nasa astronauts carrying out work on the first part of the International Space Station were beamed live around the world.
Here is a selection of views of the astronauts at work as they orbited the earth.
Astronault Jerry Ross exits the shuttle at the beginning of a marathon space walk.
High above the earth, an astronaut hangs off the shuttle's arm, carrying out delicate work as he peers into space.
Down below at Nasa's mission control, technicians watched the computer screens showing Endeavour's precise position.
The shuttle's arm held the first sections of the space station together as the astronauts worked.
One of the key mission objectives was to hook up power supplies to the Unity module of the ISS.
Orbiting at thousands of miles an hour above the earth.