The TARDIS is a time machine and spacecraft created by the Time Lords. TARDIS is an acronym that stands for Time And Relative Dimensions In Space, and was named by Susan, The Doctor's granddaughter. The TARDIS that the Doctor pilots is an unreliable and obsolete Type 40 that he stole from a museum on Gallifrey. Its Chameleon Circuit hasn't worked for many years, causing it to be locked into the shape of a 1960s Police Box from Earth. However, despite its faults, the TARDIS always goes where it needs to go, just not necessarily where it's supposed to go. On Worlds In Time it appears on every planet, for example, on Earth, it appears in the junkyard of I.M. Foreman, a reference to the first episode An Unearthly Child, as the TARDIS' first appearance was in a junkyard with the name of 'Foreman'.