Space-time travel did not necessarily require a vehicle. It could be achieved by use of a vortex manipulator or time ring, (TV: The Sound of Drums, Genesis of the Daleks) though "time travel without a capsule" was usually painful. (TV: Blink, The Sound of Drums) Because of their naturally ability to move through time, the Vist could not understand the use of a "time machine" in terms of time technology. (AUDIO: The Forbidden Time)