Midgard System
The Midgard System is located in the Midgard Sector, on the border of the United Federation of Planets and the former territories of the Romulan Star Empire and Romulan Neutral Zone. It was settled soon after the Federation's founding and has been a hub of regional defence for centuries of tension with the Star Empire, with Starbase 23 - Gateway Station - located in orbit of its third planet. The collapse of the Star Empire and Starfleet's expanding operations beyond the border has confirmed that the Midgard system will continue to act as a fulcrum for the interests of the Federation in the sector, especially Federation civilians.
History
Earth Starfleet first charted the system during the Romulan War. After the war's end and the forming of the Federation, the system's resource-rich planets and new strategic position made it worthy of settling. After the initial establishment of defensive infrastructure and observation posts, by the late 22nd century, settlers seeking a frontier life had colonised the third planet. Starbase 23 was built in the 23rd century, but little else changed beyond continued development of the system until the Romulan Supernova.
When the evacuation began, the Midgard system was considered an ideal home for Romulan refugees, but locals protested. Two centuries of living on the frontier with the elusive Romulans mere light-years away had made them cautious and unwilling to take in the old enemy. Midgard colonists were among those placing political pressure on the Federation opposing the evacuation and celebrated when it was cancelled. The changing political situation did not alter much for Midgard except to make them more cautious and defensive, as the Neutral Zone became a wild, more permeable border.
Starbase 23 was already slated to be replaced with an old Spacedock-class station when the Star Empire of Rator collapsed in 2400. The Romulan Republic expanded to take on more territory and drew closer to the Midgard system, but in Rator's wake was a slew of unclaimed and independent worlds thrown into new chaos. This precipitated Starfleet dispatching more ships to manage the frontier, rendering aid to Romulan refugees and building bridges with the Republic. Starfleet was also eager to expand its exploratory operations into old Romulan space. The arrival of Sirius Squadron has thus drawn more resources to the Midgard system and Gateway Station, but the local colonists remain wary. They have never been given reason to trust anyone or anything beyond the border.
Planets
Hrungnir (Midgard I)
Freyja (Midgard II)
A rocky world with a thin, breathable atmosphere. Much of Freyja's surface is arid, with the flat regions covered in desert. Terraforming attempts were abandoned, and any inhabitants live in habitat domes. Most residents either work at or support the research outposts and mining operations scattered across the planet.
Alfheim (Midgard III)
The home of the main and oldest colonies of the system, Alfheim is a rich, habitable world. Its surface has a variety of biomes, landscapes, and temperature ranges, and settlements are scattered across the planet. Mineral resources in the northern hemisphere, however, mean the original and largest cities were established in harsher, colder climates. The centre of government is located in the frost-bound city of Ymir, as are most of the headquarters of the planet's companies and organisations. Gateway Station orbits Alfheim.
Vanaheim (Midgard IV)
A massive gas giant, Vanaheim is surrounded by brightly-coloured rings and has numerous moons. The moons boast a variety of biomes and home various operations, but Vanaheim is most significant for its gas mining operations, with deuterium and helium-3 extracted.
Svartalfheim (Midgard V)
A small, icy world on the outer fringes of the system. It does not have a breathable atmosphere, and most of its surface is covered in glaciers, but it is rich in minerals.