Discovery crew 'sad' to see shuttle retire

The crew of the space shuttle Discovery, due to be retired at the end of this mission, has paid tribute to "the most capable vehicle that has ever flown in space".

This is the 13th time the shuttle has flown to the space station, where it has delivered a new storeroom and a sophisticated humanoid robot.

Once it returns to Earth, Discovery will be placed in a museum.

Shuttle Commander Steven Lindsey said it was a privilege to be on the shuttle's final flight, while Mission Specialist Michael Barratt said everyone would be sad to see it go.