The river that led humanity to the starsConnecting the largest solar system colonies, the Via Solaris is a Hypersea lane that resembles a river and is easy to traverse by starship. Its course has changed over the years, as if it is actually meandering. This was considered relatively harmless until 38 years ago, when the Lupus Exonis System lost its access to the Via Solaris. Since then, governments started preparing for the worst case scenario.
The Via Solaris only requires low Relativity to navigate. The massive starships traversing it would never be able to use other Hypersea lanes, due to their size preventing them from obtaining higher Relativity levels. These large ships can transport both Terraforming Seeds and large armies, which is what made the Via Solaris so crucial to the spread of humanity across the galaxy.