Dead Orbit Faction Allegiance in Destiny: The Taken King.

By visiting Arach Jalaal and talking with him, a Guardian can declare their allegiance for a particular faction. This will get you a Dead Orbit Faction Badge.

Being aligned with the faction allows for you to purchase their weapons and armor. You can also perform Material exchanges.

"It will not be easy. New battles await us among the stars, but we would rather fight on our terms than stay crouched in this coffin as the Darkness closes as the Darkness closes in. We possess the hope the Traceler gave us its dying breath. We will bnot allow this hope to wither on dead Earth. We will seed it amongst the stars.