Hyades, Known Space, and FTL Travel

Overview

Hyades is an open star cluster containing roughly between 400 and 500 star systems. In the year 301 AC, it is the home of the now unorganized human race, and is the largest region of the area called "Known Space". Known Space refers to the area that has been well charted and explored by man. The Hyades Cluster, which comprises upwards of 90% of Known Space, is the center of this area. The other, smaller, regions form a loose circle around the star cluster. These Edge Regions are the furthest reaches of humanity, and are typically territorial and unfriendly kingdoms run by those who have turned their back on the rest of their race. However, the Edge Regions are also famous for their adventurous and daring explorers, who are constantly searching for new planets to add to known space, and selling the information to Navigational Database Manufacturers. One popular quest among these explorers is searching for the fabled lost homeworld of humanity, Terra, which is believed to lie somewhere outside the Hyades Cluster.

Hyades and Empire

The history of the Hyades Cluster is shaped by The Empire of Terra. Originally, they Hyades Cluster was a number of unique alien races, and was beginning to show the start of a powerful and thriving multiracial community. This was changed by the arrival of the human Empire of Terra, which began colonizing and terraforming every planet they could reach. The Terran Genocides followed, a series of wars spanning nearly two hundred years, in which the Empire was able to effectively eliminate all non-human life in the Hyades Cluster. The Empire then renamed itself the Hyadian Imperium, declaring the entire star cluster the rightful territory of humanity. Another two hundred years after this, the empire collapsed from internal pressure. In the modern day, the last 300 years have been humanity's attempt to reconstruct the Hyades Cluster. However, now, rather than being united under a single Imperium, mankind is divided into many smaller kingdoms and territories, the largest of which is New Hyadian Federation.

Faster than Light Travel and Known Space

Currently, the only widespread mode of faster than light travel is the Jump Drive, affectionately nicknamed the J-Drive. J-Drives operate by pushing a starship through hyperspace, quickly consuming fuel until they are unable to operate, at which point the starship returns to regular space. Distances in hyperspace are significantly shorter than those in regular space, allowing ships to traverse the galaxy without technically travelling above the speed of light. A jump is considered a unit of measurement, a ship with a Jump 1 engine is capable of travelling through hyperspace half as long as a ship with a Jump 2 engine. Smaller craft usually have engines with jump capacity of 3 or lower, while the largest and most advanced ships can have drives up to jump 12. Each time a ship exits hyperspace, it's jump drive will have burned through all it's fuel, and it most refuel before it can jump again. The main ingredient of the fuel used by J-Drives is hydrogen, so while most space stations and space ports do sell fuel, the preferred method for most ships is to jump to a system which contains a gas giant, and to use what is called a Scooper to pick up the necessary gases need from the gas giant. Following this, the J-Drive will synthesize it's own fuel. This leads to the creation of Jump Chains, where ships will jump from gas giant to gas giant, picking up fuel to get where they need to go.
This is, in short, the main reason human exploration has halted at the edge of what is currently Known Space. As the J-Drive is heavily dependent on gas giants to refuel at, this also means it works most effectively in areas with lots of star systems. This makes it perfect for use within star clusters, like Hyades, but as explorers pushed outwards into less densely populated spaces, they continued to need larger and larger J-Drives to reach new worlds. Until a new method of FTL travel is developed, humanity is essentially trapped within the Hyades Cluster.