The Ship ( Arkhaven ) The Ship was the official last hope for the distant human colony of Sarath after its moon threatened to destroy the planet . ( PROSE : " City at World ' s End " ) History . For centuries , the people of Sarath had little interest in space travel , developing advanced medical technologies instead as their planet ' s moon was too distant to inspire a genuine interest in space travel . When an asteroid strike sent the moon into a descending orbit , Professor Tovel Jarrasen , a member of the Functionary class in the city of Arkhaven , proposed the construction of the Ship to evacuate the people of Arkhaven to the nearby planet Mirath . ( PROSE : " City at World ' s End " ) Appearance . Extending upwards to over a hundred stories high , the Ship was a vast silver structure officially powered by nuclear engines . It was intended to carry the population of Arkhaven , the tools and supplies they would need to colonise a new world , and some space for extra cargo . Officially , all storage capacity had been calculated before the last refugees from other cities arrived in Arkhaven , and any new attempts to enter the city or those who objected to the current situation were sentenced to the NC2 - Non - Citizen , Non - Conformist - camp , where they would be left behind to die once the Ship launched . The upper body of the Ship was also a lunar lander that would carry out reconnaissance on Mirath and find a suitable landing site , as the main body of the Ship was a simple brute - force lifter and cargo pod that would only be able to make one journey and not take off again . If a suitable landing site for the Ship could not be found , the Lander would thus be used to ferry the ' crew ' and cargo down in smaller groups , although its limited reaction mass capacity meant that it would need to be remotely controlled to lift off completely unladen after each such trip and be refuelled in orbit . The Ship ' s interior included modularised pods and cartons secured for flight , vast tanks of water and oxygen , pumping systems and air - purification equipment , and couches stacked three in a row where all but essential crew would be lightly sedated during the flight to minimise demands on life support . ( PROSE : " City at World ' s End " ) The Truth . When the TARDIS landed on Sarath a month before the moon was scheduled to crash into the planet , the crew were separated in a meteor strike . Having established his credentials as an alien with advanced scientific knowledge , the Doctor agreed to assist Jarrasen and the people of Arkhaven in offering his own insight into the Ship ' s systems . Although Jarrasen asked the Doctor to focus on helping him with the Lander , arguing that the main Ship was the simpler device that he was reasonably confident would work while also being too large to modify in such a short time , the Doctor ' s visit to the Ship allowed him to make some mental calculations based on his estimations of its dimensions and mass , structural weight , engine thrust and likely payload . Combined with his earlier suspicions when Mayor Brantus Draad had stated that the ship had been designed before a war with the neighbouring Taklarian s killed almost ninety percent of Arkhaven ' s population , yet there were still concerns about the overall passenger capacity , the Doctor realised that the Ship was a monstrous deception without the power to lift itself even once inch off the ground . In reality , Jarrasen ' s lack of funding prior to the destruction of the moon had caused him to make mistakes in his calculations , only realising after construction of the Ship began that he was only able to create an engine with a thrust capacity two or three orders of magnitude less than what was needed to power the Ship . As a result , while construction of the Ship continued to serve as a public symbol to maintain morale , members of the Functionary class created a genuine Lunar Lander to carry five hundred survivors directly to Mirath , with a new launching system constructed to boost it into space . This flight would take six weeks rather than the ten days that the Ship would have done if it was real , but it was the only chance they could find . ( PROSE : " City at World ' s End " ) Final Fate . When Zero Day was declared after the moon broke in half a month ahead of schedule , the surviving Taklarians attempted to take the Ship themselves , but their presence on board simply made it that little bit easier for Draad to destroy the fake ship and kill them . Despite Monitor attempting to stage a coup with specially - built androids , he was defeated and replaced by his own android duplicate of Susan . After the Doctor donated a ' life pod ' from the TARDIS to provide the Lander with extra volume but no additional mass so that it could take on extra survivors , the reunited TARDIS crew programmed the Lander ' s launch sequence , departing in the TARDIS as the Lander left for Mirath . ( PROSE : " City at World ' s End " )