The GX-9900 Gundam X was a Gundam Type mobile suit - a decisive battle weapon developed by United Nations Earth, equipped with the Flash System. Its greatest weapon was the Satellite Cannon, a beam cannon with enough power to destroy a space colony with a single shot, powered by Super Microwave (SMW) launched from a solar power facility on the lunar surface. Power from the SMW was stored in the backpack and a series of energy conductors spread all over the GX's body, and the backpack could also provide energy for the Gundam's other weapons, such as beam sword and rifle. Because of this, when conducting combat without firing the Satellite Cannon, the Gundam X could continue fighting for up to a week without resupplying.
The Gundam X's other key feature was the Flash System, which enhanced the thought waves of Newtypes. This system was used to access the SMW facility and conduct the initial registration of the Satellite System. It could also be used to control unmanned mobile suits known as G-Bits, with the Gundam X capable of simultaneously controlling up to 12 FX-9900 GX-Bits - a type of Satellite System-equipped Bit.