This is now a craftable item (as of v4). Its purpose is to speed up elapsed time throughout the game so <player> doesn't have to sit waiting for (eg) looting drones to return toi their mothership, or station building to complete.
The entire game will be sped up while <player> is using SETA, whether or not <player> is present in zone, system or sector, or even if they've never visited those areas before!
Its availability shows up as a blue ring in the HUD, next to the jumpdrive if you have that item
For conditions of its use, here's a copy from CBJ's post:
The conditions under which SETA is not available or which will stop it if it's active are:
• You are on a platform or otherwise away from your pilot seat.
• You are in a conversation or menu.
• You receive an important event on your event monitor.
• Your ship is attacked.
• You fire a weapon or activate a scanner.
• Your jump drive is charging or active.
• You steer hard in any direction.
• You stop your ship suddenly using the stop key (Backspace by default).
• Your ship is in close proximity to another object (except when autopilot is active).
• You collide with something (whether autopilot is active or not).
There are currently discussions underway as to precisely define when SETA can or cannot be used