From Starbounder - Starbound Wiki
Force Field is an object unobtainable by players through normal means. This item's information is present in the game files, but not intended by developers to be in players' possession.
Force Field is a semi-transparent door object found near the ends of missions.
This door is unique in that it allows passage through in one direction, but will not allow passage through the other direction.
|Apex :||This ancient looking door can only be entered from one direction.|
|Avian :||This door is going to keep me marching forward - I will not be able to come back through it.|
|Floran :||Old door won't let Floran come back through it.|
|Glitch :||Concerned. This door can only be entered from one direction. There's no going back through it.|
|Human :||This door creates a one-way force field. Anyone going through isn't coming back the same way...|
|Hylotl :||This door creates a force field that can only be entered from one side. One cannot turn back through it.|
|Novakid :||There ain't no turnin' back once I go through this ol' door.|
- Cheerful Giraffe: Added