Great Gate

The great gate is a special type of gate connecting the Frontier sector of Canis Majoris dwarf galaxy to presumably the Milky Way (although this is not confirmed). People arriving at Canis Majoris tend to arrive through the Great Gate, though mishaps happen - and the ships can be flung outwards, towards Galaxy's Edge sector, or worse.

Unlike the Frontier and Conquest sectors of Canis Majoris, the Galaxy's Edge is much farther away and has no own connections to Frontier.

History of the Gate/Stranded

While there is no direct information on who built it, why is it greater than others - though it is likely due to distances required to bridge galaxies - nor why it tends to fail (or if it works at all at the present time), after navigational mishaps the Stranded emerged as an united force within the Galaxy's Edge sector.

Once their own separate connection to Frontier is repaired/rebuilt through the actions of Captain, they are reconnected to the rest of the Canis Majoris - at least unidirectionally. In game terms, this allows the player to leave the prologue behind and enter the game proper.

As a side-effect, the Stranded also rejoin the galactic community and start competing with other major and minor factions.