The Sagittarius Reach is a vast of expanse of uncharted space, thousands of light years from Federation space. Situated at the edge of the Milky Way, one of the dominant features of this region is that it incorporates a small section of the toroidal Galactic Barrier first encountered by Starfleet in 2265. Because of the dangerous effects that the Barrier had on those sensitive to Extra Sensory Perception, the Reach has been unexplored outside of the disused automated lithium cracking station on Delta Vega I.
The USS Columbia is the first manned Federation vessel to explore this distant region following three separate incidents involving the USS Enterprise in the mid 23rd century. The Galactic Barrier’s ability to uplift individuals into omnipotence as well as the damaging effect that traversing the barrier has on starships caused Starfleet Command to ban all manned exploration of this distant corner of the galaxy. In late 2394 the Federation Quadros XII probe reported that energy readings and the mass of the barrier itself had shrank and analysts decided to begin an exploratory program.
The Columbia is not cleared to enter the galactic barrier regardless of the changes within the barrier and any scans must be conducted within a distance of 2 million kilometers. Quadros XII also detected evidence of space faring civilisations within the area and part of the Columbia's mission within this region is to make first contact where possible.
At present the only charted world within the Reach is Delta Vega I, the site of a long abandoned lithium cracking station that ceased operations long before it was visited by the USS Enterprise. This class-L world is now home to Dehner Base - a scientific research institute comprised of some of the keenest minds from across the Federation led by Professor Olivia Sellards. Construction of the base began in January 2395 and phase one of its construction was completed in September of that same year.