Planet Vort's Solar System is home to 12 planets, two of which are gas giants with small planetoids orbiting around them. Invader Vex was given the mission to wipe out all resistance or refuge camps on the other planets in the Vortian System, along with his SIR unit: VIR.
Importance to the Irken Empire
The resistance camps had to be destroyed in order for no Escapees to be able to leak information about the Irken Armada, as Vort assisted the Empire design most of their starships and quite a bit of other technology.
Only one Vortian escaped Vex's sweep: Lard Narr, leader of The Resisty. Fortunately, Vex did not let him escape with any Irken blueprints or schematics, and Lard Narr was forced to work only with his memories when attacking The Massive in "Backseat Drivers From Beyond the Stars."
Methods for Conquering
Vex conquered the Vortian Resistance camps by first infiltrating them as a stranded alien on the run from the Irkens. He then located and destroyed all information that may have compromised the Irken Empire's safety by getting close to a few key people in the various compounds. After this, he destroyed all life support as well as transportation off the planets. He then flew around blasting buildings in his Blade Runner while Commander Thresh and a small group of Irken Special Operation troops went into the larger compounds, killing people or destroying life support systems until everyone had either suffocated or been shot.
Planet Vort was made into a military research prison to design and test new Irken technology. The rest of the planets were used for additional maximum security prisons for dangerous criminals awaiting sentencing and (most likely) execution. A large piece of debris in one of the gas giants' belts is used for the most dangerous criminals, and designated Super-Max by Irken officers and prisoners alike. The true name of the prison is Super-Maximum Security Detention Center 178 . Without transportation off world, the prisoners can really only hurt themselves.
One small moon orbiting one of the gas giants is a bunker and storehouse for Vex, and contains over 100 years of provisions. Vex sets aside a portion of his income to work on this in case of some kind of apocalypse. This moon is unknown to all but Vex and a few of his most loyal friends and employees, so it is an excellent point of defense agains opposing forces.
"They don't really care about what we do to each other on the inside. The only thing they care about is the painful fact that there is no escape." -A prisoner's remark about the super-maximum detention facility