The Solas Tempus setting is a space-based science fiction setting based on Star Trek with elements from many other Sources of Inspiration.
In the Darkest Night
Set in a darker vision of Star Trek where the Federation has serious issues with classism heavily steeped in racial tensions even within its own boarders. The ideals are still alive in the hearts and minds of many but applied unfairly the farther from the core Federation worlds one gets. Other powers in the known Galaxy have their own, similar, issues and it is a rare instance where two great powers can see each other clearly across the cultural divides. Still, many forces try to bridge the gaps, maintain the peace, and forge new alliances. The galaxy is an unfair place though, and many people have fallen through the cracks of democracy.
Here and Now
Set the in year 2390, there is an old threat that has been hidden in the shadows for decades now. An unknown force only known as Onyx works to undermine the fabric of society through selective use of time travel. Their purpose is unknown and though the Federation knows of them, they cross borders and a new organization has grown out of the need to combat this threat. Born of secrecy and one of the few last bastions of truth, Solas Tempus stands as a guardian to the very fabric of history itself situated uniquely by a series of unlikely alliances their influence spans quietly across borders to fight this new threat.
Our game is centered in this universe, specifically, aboard the space station known as Nimbus Station in the oceans of the planet of Soteria in the Schatten Star System. The station is a secret facility for research and development, but now, the very anomalies which fuel that research have begun to align together forming Splices which serve as temporary gateways to different places, times, and even realities. One moment a person could be standing on a mountaintop in 1992, Earth, and the next they find themselves aboard this fateful station in the here and now, far from anything and everything they've ever known.
How?
The mechanics of how this happens are not important and fall under the category of The Fudge. It would take way entirely too much writing in the area of theoretical physics of time travel to really codify. This is why many people would prefer a magical solution to most things - no one has to explain why magic works it just does. For our purposes the temporal nexus point just works. Clearly in-game someone knows why the nexus point allows traveling to and from the station the way it does, but they aren't talking.
Hope
Since Solas Tempus was born from the broken trust and dreams of the darkest elements of the Federation, it remains a dim beacon of hope in a sea of cold political conflict. The last beacon calling out that all species, all peoples, can work together toward a single common goal when they have need. That goal, to protect the truth of the past, for what may be the last battlefield for the survival of all.