Surge Concerto Terminal
The Surge Concerto Terminal (サージュコンチェルト・ターミナル, saajuconcheruto taaminaru?), commonly abbreviated as SCT, is the main control console for the Colony Ship Soreil, and it is also the mechanism that allows it to harvest energy from the world beyond the Seven Dimensions (our world, Earth). This makes possible for Soreil to continue working potentially forever.
The SCT also houses an enormous Song Magic library, and it is the main unit that processes the Cielns, so it wouldn't be absurd to say that it also allows to entirely control Soreil by merely Singing. Likewise, since this system controls all the mechanisms that allow people to live within the ship, if it gets shut down or destroyed, nothing could live on it anymore.
The Surge Concerto Terminal itself is installed in the area of Soreil called Sora, which itself is located in the outer plates around Soreil's main body. Its original creator is Professor Clackett Palmium, but since he passed away before he could do anything beyond designing it, its creation is actually credited to the young genius Sarly Planck, who received the instructions and blueprints for its creation in a G2Tron the professor gave to her prior to his death.