Control chair

Control chairs are devices built by the Vehrians to facilitate the operation of several systems of their cities and starships. 

Functions
Taking the appearance of a large, throne-like chair, the most prevalent function of the device appears to be to directly control the targeting and launch of the primary weapon used by the Vehrians, the seeker drone. At least some degree of telepathy is required to operate the chair, and it is possible that only the Vehrians and their desendents are able to do so. ("Realisation")

Launching of the drone weapons is possible without the use of a control chair, though in this instance the weapons become autonomous, choosing targets as they see fit. ("Lost and Found")

Operation
The user's mind is directly linked to the control systems via a non-invasive neural interface that snaps into place around the forehead. The interface of the L'Vehris control chair stimulates the secretion of endorphins in the nervous system, making use of the chair a pleasurable, even euphoric experience. A holographic representation of the area is projected around this chair, allowing the user a better understanding of where they are directing the drones. ("Final Approach") The chairs aboard Olympus-class warships are not equipped with such a system, and similarly do not induce the same effects on the user. ("The Calm Before the Storm", "Oblivion")

Side effects
Prolonged use of the chair can cause the body to become dependent on the elevated endorphin levels stimulated by the interface, triggering severe withdrawal symptoms over several months. ("Survival", "Desolate")

Background
The control chair was partially inspired by the device of the same name from the television show Stargate Atlantis, which similarly allowed certain individuals to control the launch of Atlantis' weapons, among other things.