Like the TARDIS, it has become one of the icons of the programme ; spinoff media such as The Sarah Jane Adventures and Torchwood have replicated its functions in devices such as the sonic lipstick, sonic blaster, sonic pen and sonic modulator.

Doctor Who has become so much a part of British popular culture that not only has the shape of the police box become more immediately associated with the TARDIS than with its real-world inspiration, the term " TARDIS-like " has been used to describe anything that seems to be bigger on the inside than on the outside.

Despite changes in the prop, the TARDIS has become the show's most consistently recognisable visual element.

The dimensions and colour of the TARDIS props used in the series have changed many times, as a result of damage and the needs of the show, and none of the BBC props has been a faithful replica of the original MacKenzie Trench model.

However, the Doctor's TARDIS has been seen to be able to fly through physical space, first in " Fury from the Deep " ( 1968 ) and at repeated times throughout the revived series, most notably in " The Runaway Bride " ( 2006 ), in which the TARDIS is shown launching into space ( most previous incidents show the TARDIS flying only after it has dematerialised from a location ).

The TARDIS has been shown to be incredibly rugged, withstanding gunfire ( the 1996 television movie, Doctor Who ; " The Runaway Bride "), temperatures of 3000 degrees without even scorching (" Forty-Two "), atmospheric re-entry (" Voyage of the Damned "), falls of several miles (" The Satan Pit ") and sinking into pooling acid ( The Almost People ).

" In " The Doctor's Wife " the TARDIS says she has 30 desktops archived, although the Doctor has only changed it a dozen times " yet ".

When he accuses the TARDIS of being unreliable, she defends herself by saying that she has always taken him where he needed to go, if not where he wanted.

Cosmetically, the police box exterior of the TARDIS has remained virtually unchanged, although there have been slight modifications over the years.

From " An Unearthly Child " ( 1963 ) to " The War Machines " ( 1966 ), the TARDIS also had a St. John Ambulance badge on the main doors, as did real police boxes ; this has been reinstated and the window frame colour has returned to white for Matt Smith's first season as the Doctor, shown in 2010.

The TARDIS lock's security level has varied from story to story.

Alien influences have also, for example, trapped the Doctor's TARDIS and drained its power in " The Web Planet " ( 1965 ) and " Death to the Daleks " ( 1974 ), while its course has been diverted by " The Keeper of Traken " ( 1981 ), the " Mandragora Helix " ( 1976 ) and by the Daleks ' " time corridor " in " Resurrection of the Daleks " ( 1984 ).

In " The Stolen Earth " the Tenth Doctor is shot by a Dalek's energy weapon, which has always been shown to instantly kill any other lifeform, yet is still conscious and able to return, with the aid of Rose, Donna and Jack, to the TARDIS in order to regenerate.

It has been suggested that, since perfecting the science of time travel, they have withdrawn, bound by the moral complexity of interfering in the natural flow of history ( compare with the Prime Directive from Star Trek ); in " Earthshock ", the Cyberleader, when notified of the arrival of a TARDIS, is surprised at the presence of a Time Lord, stating " they are forbidden to interfere ".

In the revived series, the TARDIS has an organic look, and the Doctor states in " The Impossible Planet " that TARDISes are grown, not made.

Apart from the ability to travel in space and time ( and, on occasion, to other dimensions ), the most remarkable characteristic of a TARDIS is that its interior is much larger than it appears from the outside.

The Time Lords are able to divert the TARDIS's flight path (" The Ribos Operation " ( 1978 )), or have the ability to totally override and recall any TARDIS by the order of the Council (" Arc of Infinity " ( 1983 )).

However, this trick was used in turn by the Empress of the Racnoss, which pulled the TARDIS from the creation of the Earth to only a few minutes after its initial departure.

While the Master begins the process of transferring the Doctor's remaining regenerations to him, Dr Holloway is able to connect the last power circuit in the console room, sending the TARDIS into a time-holding pattern just moments after the turn of midnight, staving off destruction of the Earth.

When the TARDIS crew arrive on the derelict space station Terminus, Nyssa's adventures with the Doctor come to an end, as – to Tegan's horror – she elects to stay on board the Space Station in order to help free the enslaved guards and turn the station into a real hospital.

When Compassion had travelled in the TARDIS for some time, the signals of the Doctor's time machine began to turn her into a living TARDIS.

A race of werewolves, the Wereloks, turn the Fourth Doctor into a werewolf in the Doctor Who Weekly comic strip story Doctor Who and the Dogs of Doom ( DWW # 27 -# 34 ), although he manages to devise a cure for his condition in the TARDIS.

Later in the same episode, the key fob, when again used by the Doctor, shifts the TARDIS " just a second out of sync " ( one second into the future ), rendering it invisible and so hiding it from the Master.

* The Brigadier mentions an earlier adventure during which the TARDIS became invisible, a reference to the events of the 1968 television serial The Invasion.

An alien intelligence has invaded the TARDIS and rendered the First Doctor invisible, leaving Dodo Chaplet and Steven Taylor incredulous.

The visual stabiliser has been damaged, rendering the TARDIS invisible, so they try to find Professor Edward Travers ( of The Abominable Snowmen and The Web of Fear ) to seek his assistance.

Arriving inside Torchwood HQ via the TARDIS, The Doctor and Jackie, who is mistaken for Rose, are imprisoned and then given the reason for the ghosts ' appearance — an invisible breach in the universe through which a mysterious spherical object has arrived.

K-9 appears briefly at the end of the episode, where he assists Sarah Jane's computer Mr Smith and Torchwood to create a lasso of temporal energy, allowing the TARDIS to tow the Earth back to its original position in time and space.

During the trip back to Gallifrey in the Doctor's TARDIS, the vessel shakes, causing the box containing the Master's remains to shatter and allowing a sentient ooze to escape from it.

The 2000 Big Finish audio play The Apocalypse Element attempts to explain this decision by introducing a plot point in which the eye of the Sixth Doctor's companion Evelyn Smythe is keyed to a Gallifreyan security system so as to confound enemy expectations by allowing entry only to the most unlikely of candidates, the Doctor speculating after the crisis is over that the TARDIS may retain some sensitivity to human eyes in the future.

Barbara remains level-headed and logical, allowing the Doctor to trace the source of the distress to telepathic influences from the TARDIS ( which is trying to warn them of a major failure ).

Throughout the New Adventures, the Seventh Doctor is tormented by the knowledge that he might become the Valeyard, with it being implied that his potential presence in the Doctor's mind drove the Sixth Doctor to commit ' suicide ' by allowing the TARDIS to be caught in the Rani's tractor beam.

The Sisterhood chant " Sacred Fire, Sacred Flame " in a circle, allowing Maren to see the TARDIS reflected in her ring.

He cleverly orders the last piece to move using the Toymaker ’ s voice from inside the TARDIS, allowing them to depart while the Toymaker ’ s world is destroyed.

He retrieves the ring from Namin's corpse and hide in the TARDIS to avoid detection ; Sarah suggests they should just leave in the TARDIS, because they know that the world did not end in 1911.

The Doctor watches the Dominator ship being destroyed and then heads back to the TARDIS where he and his two companions must depart in a hurry to avoid the advancing lava flows from the new volcanoes ...

The Doctor then dispersed the Key, earning the Black Guardian's eternal enmity and forcing the Doctor, for a period, to attach a randomiser to his TARDIS to avoid being tracked through time and space.

The TARDIS is the alluring prize at the end of the game, and to reach it you need to win dice throws, relying on luck, and avoid the electrified spaces beyond the proper squares.

The explosion of the mercury fluid link forces the Second Doctor and Jamie McCrimmon to evacuate the TARDIS to avoid mercury fumes, and until the mercury can be replaced, the craft is marooned.

At the end of the novel, she stowed away in the TARDIS, making brief appearances in some subsequent stories but managing to avoid detection by the Doctor and his companions until Timeless.

The TARDIS is removed to prevent their escape and hidden with hundreds of facsimiles to prevent detection.