Nerva Beacon

The Nerva Beacon (later just called Nerva and nicknamed The Ark) was a space station located in the Sol System.

Early history
The Fourth Doctor thought that the station (or parts of it) were built in the late 29th or early 30th century.

The original purpose of the space station was, for thirty years, to function as a beacon (hence the name) to warn spacecraft about the planetoid Voga, which in turn orbited the planet Jupiter. Nerva was at that time operated by the Interplanetary Space Command, which had its headquarters on Earth.

In a time period after the Cyber-Wars, Nerva had a transmat link to the breathable interior of Voga. Nerva was apparently struck by a plague that wiped out nearly all of the fifty-strong ISC crew. Only three of the crew (Commander Stevenson, Lester, and Warner) and one observer survived. It was soon discovered that the plague was in reality an infection spread by invading Cybermen, who planned to destroy Voga. (DW: Revenge of the Cybermen)

Later history
The Beacon was moved to Earth orbit, where it acted as a cryogenic storage facility, nicknamed "The Ark". Scientists had foreseen that for 5000 years the Earth would become uninhabitable due to solar flares, and under the leadership of the Earth High Minister had chosen Nerva as a "lifeboat". (The rest of humanity was evacuated in Thermic shelters, but they were apparently not expected to survive long enough to repopulate.)


 * It is unknown exactly how much time had passed, though the Earth High Minister mentioned in a recorded revival speech that "you have slept longer than the recorded history of mankind" (supposedly referring to the planned 5000 years rather then the period really slept).

DNA samples of Earth's flora and fauna were stored on board, and the bodies of specially selected human volunteers were placed into suspended animation. People stored were genetically screened so that the genetic pool of the survivors would be crossmatched, balanced and compact-evaluated. For this reason regressive humans, typified by 20th century humans, were not allowed.

The power for the station was by this time provided by solar stacks, and the transmat link now connected the station with Earth, rather than Voga.

Due to a Wirrn infestation, a massive system failure occurred and the humans overslept. By the time they did wake, up 10,000 years had passed. The awakening humans had to fight off the Wirnn, but eventually managed to retake the station and start recolonising the Earth. (DW: The Ark in Space)

During those thousands of years, the Nerva Beacon had become a legend, the lost refuge of mankind, sleeping while the rest of humanity was expanding their empire into the rest of the galaxy and even into the Andromeda. (DW: The Sontaran Experiment)