By watching tutorial djaydino gave me i made a parent object which contains both the camera and the player with the translate action (which moves object without rigidbodies i.e. unaffected by physics) and set it to late update with self as space. Now, because my ship moves with set velocity, it also needs to have fixed horizontal movement without physics involved. So, i put translate on the player too, with late update but world as space. It works, but the ship has a noticeable jitter
And i tried Sid's solution, it works perfectly, child ship under the camera, and move with translate instead set velocity