Every other upgrade gives a bigger benefit.
1 storage = 50% more carrying capacity.
1 reactor = move two more spaces if used to move
1 drill= 100% more drills per action.
1 thruster = 33% more movement.
So shouldn't thrusters give you two more moves instead of 1?
Unless I'm mistaken, 1 thruster(rocket) gives you 50% more movement. It also is "cheaper" costing only 1 tile vs. 2.