The Gate of Hades is a doomsday device left unfinished by the UPDO After it was deemed a terrible weapon. The Androva repaired what was left to convert into a hunting post, then later after the Human-Androva War, used it as a Earth Base to defend in against humans. It was later destroyed after crash-landing on Earth 10,000 years into the past, and then after being rediscovered, blown up by Jack Morrison in the year 2009.
The UPDO Set up the Orbital System Pact to develop a defence grid around UPDO-Owned planets. It was semi-completed in the 31st Century, but deemed too hazadous. The system was not operational until 3130 when Androva repaired it.
Due to the Androva-Human War, it was used to devastate several areas of the Earth, and then refitted to prevent recolonisation of the doomed planet.
By 4048, It was the last ODN-Type Orbital Station, and two years later it was missing in action.