The Tethered Aerial Release Developed In Style (abbreviated TARDIS).
Unlike it's namesake, was a hot-air balloon, created for Jackson Lake while he was under the impression that he was the Doctor. It was piloted by the Tenth Doctor, and was key in the destruction of the CyberKing.
Trivia
The balloon was described by Jackson Lake as being powered by gas, yet when piloted by The Doctor, it was powered by only hot air.