The Osterhagen Project was a planetary 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)