Osterhagen Project The Osterhagen Project was a defence weapon consisting of a series of nuclear warheads placed at strategic points beneath the Earth ' s crust and a last resort that would sacrifice the planet in the hope of taking its enemies with it . Overview . The Osterhagen Project was a planet ary self - destruct system . It was meant to be used only if humanity were suffering unbearably , with no hope of help ever coming . The Osterhagen system was a chain of twenty - five nuclear warheads placed in strategic points beneath the Earth ' s crust . If the key was used , the system would be activated and the Earth would be ripped apart . The Osterhagen keys were distributed among various high - ranking UNIT personnel across the globe . There was at least one key for each of the five stations known to be operational . ( TV : " Journey ' s End " ) In 2009 , General Sanchez was in possession of an Osterhagen key . During the Dalek invasion of Earth , Sanchez authorised Martha Jones to use it if she failed to contact the Tenth Doctor . ( TV : " The Stolen Earth " ) Two other keys were given to UNIT soldiers in Africa and Asia . ( TV : " Journey ' s End " ) Osterhagen stations . There were at least five Osterhagen stations located across the world but only three needed to be manned for the system to work . Osterhagen Station 1 was located sixty miles outside of Nuremberg , Osterhagen Station 4 was located in Liberia and Osterhagen Station 5 was located in China . Another station was located in Argentina . ( TV : " Journey ' s End " ) History . Threatened use . After Earth fell to the Dalek s , in 2009 , General Sanchez of UNIT gave a key to Martha Jones , along with the prototype of Project Indigo , to escape . However , former Prime Minister Harriet Jones told Martha Jones not to use the Osterhagen key under any circumstances . ( TV : " The Stolen Earth " ) Believing the Dalek invasion unstoppable , Martha Jones made her way to Germany . She activated the station there and contacted two UNIT soldiers , one Anna Zhou of China , another a Liberian who refused to give his name . UNIT protocol stated that the keys should be used immediately upon the activation of any three stations , but Martha Jones delayed their use to offer the Daleks a chance to surrender . Discovering that the Doctor had been captured , Martha attempted to blackmail the Daleks into releasing him , but the Daleks transmat ted her to the Crucible before she could insert the key , disarming the system . Martha Jones claimed that the Earth would be ripped apart , making the reality bomb useless , since it used Earth as part of its mechanism . After the War in the Medusa Cascade , the Doctor asked Martha to persuade UNIT to dismantle the " Osterhagen Project " altogether , to prevent it being abused in the future . ( TV : " Journey ' s End " ) Principle . During the Second Dalek War , the planet Auros was once found burning by the Doctor and the crew of the " Wayfarer " . Her captain , Jon Bowman , described the devastation as " the Osterhagen Principle " . The planet had been destroyed to stop it from falling to the Dalek s as their fleet drew nearer . Nevertheless , the Daleks anticipated this move and the Auros evacuation fleet was driven into a trap devised by Dalek X . ( PROSE : " Prisoner of the Daleks " ) Other information . Though the Doctor had asked Martha to see to the dismantling of the Osterhagen Project , ( TV : " Journey ' s End " ) its use on Auros during the 26th century showed that some trace of information regarding the Osterhagen Project lived on , either through classified files or word of mouth passed down by high - ranking officials . ( PROSE : " Prisoner of the Daleks " ) The German woman who provided food for UNIT forces at Osterhagen Station 1 implied that the Project had been around since her visit as a youth to London . ( TV : " Journey ' s End " ) Jack Harkness of Torchwood 3 was able to learn the details of another top - secret UNIT initiative , Project Indigo , but he had no knowledge of the key . However , several people outside UNIT knew of the key , such as former Prime Minister Harriet Jones . ( TV : " The Stolen Earth " ) The Doctor surmised the Osterhagen Project and key were invented and named after someone called " Osterhagen " . ( TV : " Journey ' s End " )