Crews from the international space station and shuttle Discovery, said a heartfelt farewell, to mark the spacecraft's final mission.

On its final voyage after nearly three decades, Discovery, the most travelled space craft, will be retired after its return.

The hatches between Discovery and the International Space Station were sealed Sunday afternoon, setting the stage for the shuttle's departure on Monday. Mission Control gave Discovery's astronauts two extra days at the orbiting outpost.

The extension stretched the entire mission to 13 days, putting Discovery's space flight days at exactly one year.