The vortex loop was a component in the Doctor's TARDIS. (NOTVALID: Attack of the Graske)
Behind the scenes
In Attack of the Graske, the vortex loop was operated by the player at home with either the digital remote control or a computer mouse which has been temporarily linked with the sonic screwdriver. If the player chose incorrectly, the Tenth Doctor, who was busy elsewhere in the TARDIS tracking a Graske, picks it out for them. Due to the differing outcomes of the game, including who actually operates the vortex loop to chase the Graske, and no way of measuring the "true" or "correct" outcome, this wiki does not consider Graske to be a valid source.