Typically, a Byblos conversion took an abandoned mine and transformed it into a fully working space station. A pressurized hangar, sealed from the vacuum by a forcefield, permitted small spacecraft such as Utility Tugs or Corellian transports to dock. Mineshafts that led to the exterior of the asteroid were either blocked off, or became the site of a defense emplacement—typically a turbolaser turret or similar laser weapon. Crew quarters and station facilities were located in the hollowed out space at the core of the asteroid.
Because, throughout the galaxy asteroid fields were key locations for mineral extraction, many asteroid fields were riddled with abandoned mineworkings, hollowed out asteroids ripe for conversion into habitable bases. This ubiquity was due to several reasons, including but not limited to plentiful suitable locations, low transportation costs, and minimal environmental impact. Thus, because so many dormant or exhausted deep space quarries existed, monitoring them all was impossible. Therefore the Asteroid Hangar was an ideal location for groups wishing to keep their presence hidden from unfriendly eyes. Furthermore, thick layers of rock were able to mask electromagnetic emissions from passing Probe droids or Scout Craft, and machinery that could not be hidden was easily disguised as disused mine equipment.
However, the expense and secrecy involved in the conversion process was such that great organizational care need to be taken to ensure that these measures were effective. Often, pirate groups lacked the expertise or temperament to utilize a base of this kind, and so Asteroid Hangars were more unusual than might be expected, given the almost unlimited choice of locations available. When such a facility was built, it might have been used for several purposes. Secret research and development projects might have been undertaken in seclusion deep within the bowels of the rock. Squadrons of starfighters could have been housed and maintained, with the asteroid providing more protection than a spacecraft's hull.