The GDSS Philadelphia is an orbital command station that acts as the primary command and control center for GDI forces worldwide. While the station's function is strategic command, with global command posts interfacing with its EVA unit, it can also provide limited tactical support, as it is capable of deploying drop pods.
The Philadelphia was completed prior to the Second Tiberium War and acted as the central command center for GDI forces. GDI was only able to construct such a complex because of their victory and that they were now the Earth's main government. During the Second Tiberium War General James Solomon coordinated GDI efforts to combat the resurgent Brotherhood, often making use of the station's offensive capabilities to assist his ground commanders. It was also in a transmission to the Philadelphia that Kane announced his return to GDI, where he engaged in a short war of words with Solomon.
During the Firestorm Crisis increased ion particle activity in the upper atmosphere severed links between Earth and orbital assets, including the Philadelphia. GDI global command was assumed by Southern Cross until the conditions passed.
Following the war, there was an effort to move control of the ion cannon satellite network onto a space based platform such as the Philadelphia. However, this would have required building another space station at tremendous cost. Instead GDI elected to upgrade the Philadelphia to handle some of the control tasks but kept the rest of it planetside at Goddard Space Center. This idea of ground controls was a result of SpaceCom wanting to save money. By the Third Tiberium War the station was in the final stages of its upgrades and ground support was provided by a Chilean spaceport in Blue Zone 8.
In preparation for a new war, General Kilian Qatar planned a strike against the station when it hosted the annual GDI Energy Summit in 2047 to kill GDI's top political and military leaders. After disabling GDI's A-SAT defenses, a nuclear ICBM launched from a secret Egyptian facility struck the station on the fifth day of the summit. The station was destroyed with 1,047 dead. Significant debris fell into Congo Red Zone.
The destruction of the Philadelphia and coordinated global attacks allowed the Brotherhood to overrun several Blue Zones and GDI command centers in the opening stages of the war. Most GDI council members were killed, resulting in Redmond Boyle becoming the commanding director.
|The following is based on the Nod campaign for Tiberian Sun and some details might contradict canon.|
With Hammerfest under Nod banners, the Brotherhood set about delivering the coup de grace to GDI: deploy three TEL-launched ICBMs straight on the GDSS Philadelphia, the only roadblock standing between Nod and total victory. The missiles were successfully launched, blowing the Philadelphia out of the stars and paving the way for the World Altering Missile to launch - to which Anton Slavik noted in a twisted sense of Nod humor: "Peaceful, isn't it?". The deployment was time constrained as within three orbits Philadelphia would have acquired the targeting data needed to strike the ICBMs from orbit. Once all orbits are acquired, all would be for naught for the Brotherhood.
The Philadelphia has artificial gravity. On videos from the station, people walk around in what seems to be a one-G environment. It also houses a "zero gravity" barrack and launch station to deploy drop pod reinforcement, as seen in the intro of Tiberian Sun.