Crucible

The Crucible was the flagship of the Dalek Fleet of Davros's New Dalek Empire. It existed at the centre of the Medusa Cascade. It appeared was a massive spherical space station, the size of a planet, with numerous docking ports on the outside.

During the War in the Medusa Cascade when the New Dalek Empire invaded the captured Earth, the Crucible was at 90% efficiency. (DW: "The Stolen Earth"). Human prisoners were taken for the testing of the reality bomb during the Dalek invasion of Earth in 2009. The Crucible was to be the staging post for the deployment of a reality bomb that would have destroyed all of the universe except for the inhabitants of the station allowing the Daleks to be the sole survivors in existence. It was destroyed, along with Davros and all of the Daleks, by the Doctor's clone. (DW: Journey's End)

Behind the Scenes

 * The Crucible seems to resemble the Death Star from Star Wars in a few respects, including its shape and size.