If you lost the vial of thioseptal, your only recourse is to search space at about range 1200 to 1500 away from the star, in each system after St. K's until Jiang's Star. Drop a crate at the middle of the star, and keep the crate targeted as you fly through space, so you can see the range. Even with this, finding the gate without the vial is usually tedious.
Download and Play in 1.9 beta 1... Drake Technologies (Alpha): More hardware for combat in parts 1 and 2! Star Castle Arcade: Play a classic arcade game adventure, with or without more features (like powerups)! Playership Drones: Buy or restore exotic ships to command!
Other playable mods from 1.8 and 1.7, waiting to be updated... Godmode v3 (WIP): Dev/cheat tool compatible with D&O parts 1 or 2.