As one of the ships is cutting through the doors of the asteroid-base, it is torn appart by a railgun mounted on the exterior. Whilst the remainder get through. Some of the large groups are vented out of the asteroid into space via various blast doors across the outer layers of the asteroid whilst interior defences activate (eg turrets and doors) slowing down the offensive a lot and causing some casualties whilst a force of pirates fortify the interior of the base, maintaining the heavy railgun fire on the battleship and breaching it's armour in places whilst the base calls for aid.
