Deimos was purchased by the United Earth Government in 2395 and the pre-construction phase of the Marathon Project was started ten years later in 2405. In 2408 conversion of the moon into a ship began. The project ended in 2472 with the completion and launch of the Marathon. This was more than 300 years prior to the events portrayed in the game Marathon (see Timeline for the full history).
"Mankind will venture out past its earthly bounds, and move into a future grander and more real than the total of its own written history. This, the grandest achievement mankind has ever conceived will be for the purpose of peace and the preservation of the human race. May this great technological ark carry with it the sum total of all human wisdom, and may neither time nor distance weaken our common ties."
- UESC president Marcus Tiberius Buendia, on the eve of the launching of the Marathon.