|WARNING! This article contains MAJOR spoilers for the recently released episode That Hope Is You, Part 2. Caution is advised.|
The distortion field was a 32nd century Federation technology, a system to shield and conceal the location of Federation Headquarters within the galaxy's Alpha Quadrant following the Burn. (DSC episode: "Die Trying")
History and specifications
The distortion field was generated by the Federation HQ space station and appeared like a bubble around it and the docked Starfleet ships. From outside, the appearance had a mirroring effect. Via power cables connecting the fleet with the station, the distortion field was sustained by the collective energy of the vessels held within.
In the year 3189, the crew of the time-displaced 23rd century Crossfield-class science vessel USS Discovery discussed the distortion field when they arrived at the station. Inspector Adira Tal of the United Earth Defense Force had provided the Discovery with the coordinates, and Captain Saru established contact in advance of their arrival. (DSC episode: "Die Trying")
Following the defeat of Osyraa and the disintegration of order within the Emerald Chain, the surviving Federation reached out to other worlds again. The distortion field, however, remained in place around HQ. (DSC episode: "That Hope Is You, Part 2")