Beginning Starship Combat
When the crew of a starship has hostile intentions toward another vessel, they go to their battle stations and activate their starship’s targeting systems. This is clearly obvious to all other starships in the vicinity with working sensors, though there could still be a chance a hostile vessel can be talked down, if the GM allows it.
In general, the GM decides when starship combat begins, where the combatants are, and which way their starships are facing. This might mean that both sides are facing each other from opposite sides of the grid. However, their relative positions and facing can also be established randomly. Roll 3d6+5 to determine how many hexes separate the opposing sides. If either side consists of more than one starship, this result is the distance between the highest-tier starship on one side of the battle and its counterpart on the other. Other starships should be placed within 3 hexes of an allied starship. Then, roll 1d6 for each group of starships to determine the facing of the starships in that group, with a 1 meaning the starships are facing the top edge of the grid, and with 2 through 6 proceeding clockwise around the hex.
Source
Core Rulebook pg. 316